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Running One VC on a DVC Sub

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URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=74640
Printed Date: December 08, 2021 at 12:38 AM


Topic: Running One VC on a DVC Sub

Posted By: 1lowgalant
Subject: Running One VC on a DVC Sub
Date Posted: March 17, 2006 at 3:16 PM

We'd like some feedback from other installers out there. We're having a little debate on how you can wire a 4 ohm dvc sub. One of our installers says you can run only one voice coil to get a 4 ohm load with no problems. He says he's done this for years with no problems. I, on the other hand, disagree. If you are running one 4 ohm dvc sub, the only ways to do it are a 2 ohm load or an 8 ohm load using both voice coils. I know I've seen subs suffer damage due to running only one voice coil on a dvc. Any feedback would be great. Thanks.



Replies:

Posted By: bmwpwner
Date Posted: March 17, 2006 at 3:35 PM

i am the other installer in the mentioned shop. i have used only 1 4 ohm coil on DVCs for years with no ill effects. why is this not considered a proper method. from my understanding that is the whole point of having a DVC. you can go either 4, 8, or 2 ohm loads depending on the wiring. what is the downfall of using only one voice coil? and if i am wrong then i am the luckiest man alive because i have never had a setup come back broken for such an improper connection. everyone needs to take me to the casinos LOL! seriously, i would like to know if i've been wrong all these years.

thanks



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"I cannot teach anybody anything, I can only make them think."
-Socrates-




Posted By: haemphyst
Date Posted: March 17, 2006 at 4:07 PM
1lowgalant wrote:

I know I've seen subs suffer damage due to running only one voice coil on a dvc.

No, you have not. Not SPECIFICALLY from only running one voice coil. What was probably the CAUSE of the damage, if there was truly damage done, was from overpowering the single voice coil. When you are running one coil, the power handling is cut in (close to) half - i.e. a 200 watt DVC woofer will only handle 110 watts (or so) when one coil is powered - NOT the full 200 watts the woofer is RATED for... I also have run one coil from DVC woofers for MANY moons, and have never had any issues.

I have actually used the second voice coil for a system "tuning" device. By adding a fixed or adjustable resistor, you can actually adjust the elctrical Q of the woofer, (ala this article, posted by Steven Kephart of Adire Audio) which will affect the toal Q of the system. Nice. Thanks, Steven!

I have also built RLC networks in equal and opposite resonant peaks (equal and opposite peak of the woofer in the enclosure) for tuning out peaks in enclosures that are too big... a "passive, fixed, single band, parametric EQ", as it were...also nice. Steven, you DO know I was doing that before you posted that link originally, right? posted_image

No, ABSOLUTELY NOT, there is NO (as in none, nada, niet, niente) damage that can be done to a DVC woofer just by runnning one coil, as long as the system's power handling is adjusted. I will say that forever, until I am proven wrong. Nice thing about blowing one coil? You have a second one to go through BEFORE you have to buy another woofer! posted_image

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: Francious70
Date Posted: March 17, 2006 at 4:36 PM
There really is no problem with running only 1 voice coil. Check out Ascendant Audios old subwoffers. They were DVC and reccomended you use only 1 voice coil, and use the other one with a potentiomoter for a varaible QTS system.




Posted By: stevdart
Date Posted: March 17, 2006 at 7:06 PM
I agree with haemphyst as well, so bmwpwmer wins this argument IMO.  (But haemph...I believe Dan Wiggins wrote that paper and I've seen S.Kephart attribute it to him.)  Anyway, this doesn't delve into the issue of why such a thing is done in the first place though.  Did you need to use those particular subwoofers so badly that you had to rig normal wiring methods to make them work?

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.




Posted By: jeffchilcott
Date Posted: March 17, 2006 at 11:50 PM
very very interesting article...gives me some new ideas!

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2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR
2007 USACI World Champion
2007 World Record
2006 USACI Finals 2nd Place




Posted By: bmwpwner
Date Posted: March 18, 2006 at 12:12 AM

i used to work for a "mom & pop" shop that didn't know mobile from a hole in the ground so instead of confusing them with single 8ohm and 4ohm woofers we told them to just get DVC because they are kinda like a hermaphaite speaker. they can be wired to be a 4 ohm speaker in single woofer apps, 8 ohm woofers if using 2 woofers and bridging it into a 2 channel 2ohm stable amp, or 2 ohm if we needed to use a mono amp. like i said before i have been doing it that way for 10 years and haven't had a problem yet so i was very curious to see if i had been doing it wrong all these years. also, i have seen woofers come back abused enough to blow the single voice coil that had been used and just switch the wires to the other coil and it work perfectly. anyway, thanks for all the feedback on this bet. i guess i win and the other installer will be working a double shift for me now LOL.



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"I cannot teach anybody anything, I can only make them think."
-Socrates-




Posted By: willdkartunes
Date Posted: March 18, 2006 at 12:22 AM
bmwpwner wrote:

from my understanding that is the whole point of having a DVC. you can go either 4, 8, or 2 ohm loads depending on the wiring. what is the downfall of using only one voice coil?


You are completely correct! That is exactly the point of having a DVC subwoofer. Different wiring options! The only downfall to wiring only one voice coil is you have to run lower wattage to the subwoofer. Of course, there is an upside too. (already stated earlier by haemphyst)

I knew guys that use to do this all the time when I was younger. (hook up only one voice coil of a DVC sub) They loved this new idea of subwoofers having dual voice coils. Don't know how it first started, but a very cool invention. So is the removable voice coil.... very sweet. Much cheaper too!



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Do whatever makes you happy in life without diminishing the happiness of others




Posted By: haemphyst
Date Posted: March 18, 2006 at 11:00 AM
stevdart wrote:

(But haemph...I believe Dan Wiggins wrote that paper and I've seen S.Kephart attribute it to him.)

Ahhhh, but if you re-read my post, I only said Steven POSTED it, not wrote it... posted_image

To whit:
haemphyst wrote:

(ala this article, posted by Steven Kephart of Adire Audio)


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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: stevdart
Date Posted: March 18, 2006 at 12:15 PM

]Ahhhh wrote:

but if you re-read my post, I only said Steven POSTED it, not wrote it... posted_image

posted_image  Sorry...my bad.



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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.




Posted By: 1lowgalant
Date Posted: March 21, 2006 at 5:19 PM

If i'm wrong, i'm glad to finally know the truth. this will save me alot of headache in the future. but, haemhpyst, don't tell what i have or haven't saw. if overpowering one voice coil can damage the sub, then like i said, running only one voice coil CAN cause damage. think about how you say something before you say it.



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Whatever you do, DO NOT let the white smoke leak out of the wires.....




Posted By: stevdart
Date Posted: March 21, 2006 at 6:25 PM

]think wrote:

about how you say something before you say it.

1lowgalant, you should read it again:

haemphyst wrote:

1lowgalant wrote:

I know I've seen subs suffer damage due to running only one voice coil on a dvc.

No, you have not. Not SPECIFICALLY from only running one voice coil. What was probably the CAUSE of the damage, if there was truly damage done, was from overpowering the single voice coil. When you are running one coil, the power handling is cut in (close to) half - i.e. a 200 watt DVC woofer will only handle 110 watts (or so) when one coil is powered - NOT the full 200 watts the woofer is RATED for..

Believe me, haemphyst was not only very clear in what he said, he was also very polite...

...for haemphyst.   posted_image



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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.




Posted By: 1lowgalant
Date Posted: March 21, 2006 at 7:58 PM
i know exactly what i said and what he said. what he said was assuming i had no common sense on running one voice coil halfing the handling power. i know this and understand it very clearly, but most other people do not. Thus, running one voice coil, with the power to run two, can damage a sub, exactly what i was refering to. the only thing i was curious about was running one vc and the sub staying balanced. now that i think about it, and have backup feedback, i understand this end now. as far as power handling, i knew this already but i didn't clearly state this assuming people knew what i was talking about but go figure.  i never said i was right or wrong, just misinformed . anyways, thanks for mostly all of the feedback.

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Whatever you do, DO NOT let the white smoke leak out of the wires.....




Posted By: DYohn
Date Posted: March 21, 2006 at 8:44 PM
1lowgalant, please chill out.  There is no need for hostility.

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Support the12volt.com




Posted By: stevdart
Date Posted: March 24, 2006 at 7:56 PM

Just to explain the way we answer questions in the forum: 

Since these questions and answers are read by a lot of people, a good respondent like haemphyst (along with most of the regular contributors) will provide more reasons for a given problem than your situation alone might call for.  1lowgalant, given that you are an experienced installer, it is assumed from the start that you know that one coil of a DVC driver would take only half the power of both combined.  But a lot of readers who are looking to the 12volt.com for guidance don't know that, or at least haven't given it any thought.  These threads are ways to get the information out there in a variety of ways, and threads like this one allow the forum to do that.

It takes only a few times of leaving important parts of the big picture out of the response, and then getting called on it by another member, to get into the habit of "covering all bases".



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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.




Posted By: aaron9999a
Date Posted: March 31, 2006 at 1:41 PM
Ok, how about running each voice coil with a different amp (of the same type with the same settings)?




Posted By: stevdart
Date Posted: March 31, 2006 at 3:07 PM
Check out, er, that is to say, read the Dan Wiggins paper that was linked on the previous page.  It's got your answer.  But the quick and dirty is:  sure it's okay...it's 2 channels with two mono amps as much as its two channels with one combined 2-channel amp.  It would even be considered "two channels" if both the amps in question were bridged 2-channel amps.  This thread talks about it.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.




Posted By: MrSuperStar
Date Posted: April 04, 2006 at 1:29 PM
"Dual Voice Coils: For increased system flexibility, the woofer has two 4-ohm voice coils. When the voice coils are wired in parallel with each other, the woofer presents a 2-ohm mono load. When the voice coils are wired in series with each other, the woofer presents an 8-ohm mono load. -->In addition, each coil may be connected to a different amplifier channel and each channel will see a 2-ohm load.<--"

This was quoted from crutchfield about the Alpine type R. My question is about what's in between the arrows. Why would each channel see a 2 ohm load if its a dual 4? Is this a typo?




Posted By: DYohn
Date Posted: April 04, 2006 at 6:36 PM
Looks like a typo.  Should be 4-ohms.

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Posted By: 1lowgalant
Date Posted: April 04, 2006 at 10:14 PM
sorry for getting ill guys. thats my bad. thanks for all the feedback. this will help me out in the future.

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Whatever you do, DO NOT let the white smoke leak out of the wires.....




Posted By: audiocableguy
Date Posted: April 05, 2006 at 10:07 AM
If you were to add a Pot to adjust Q what impedence would you use?




Posted By: haemphyst
Date Posted: April 05, 2006 at 4:29 PM
I would use a 2 ohm to 16 ohm, 5 watt (or so), linear taper pot. (The resistance stated on any pot is the maximum resistance - so a 2 ohm pot, or a 16 ohm pot, or something between those values should be fine...)Probably wont HAVE to have a 5 watt power handling, but too small might burn out... I have never done any experiments to figure the actual power produced by a secondary voice coil. The lower the resistance the pot is, the more power it will need to be able to dissipate.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: proatthagame
Date Posted: May 12, 2006 at 12:46 AM

haemphyst wrote:

(ala this article, posted by Steven Kephart of Adire Audio)
[/QUOTE]

Insert from article above

What about driving just a single coil, and leaving the other open? Well, as you would guess, the push is weaker. The system has a peakier resonance (for the techie types, Qts increases because Qes increases). BUT - let's drive one coil, and short the other. Guess what? Things change from the original (both coils driven) situation, but they also stay the same. The driven voice coil is pushing and pulling, as normal. But what about the shorted voice coil? Well, it's trying to keep things at rest - it's trying to resist ANY motion! The net result is the overall peakiness of the resonance is the same as it was when both coils were driven, even though we are only using half the motor (driving one coil). The other coil helps "tame" the driven coil, so that the system basically behaves the same as before.

He mentions driving a single coil and leaving one open and driving a single coil and shorting the other. What is the difference between the two?



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Yours Truly




Posted By: DYohn
Date Posted: May 12, 2006 at 8:50 AM

proatthagame wrote:

He mentions driving a single coil and leaving one open and driving a single coil and shorting the other. What is the difference between the two?

With non-driven coil shorted, Qts remains equal to listed specs with both coils driven.  With non-driven coil open, Qts changes.  In any case,  power handling capability is cut in half



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Posted By: proatthagame
Date Posted: May 13, 2006 at 2:53 AM
So how do you short a voie coil?

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Yours Truly




Posted By: Steven Kephart
Date Posted: May 13, 2006 at 5:20 AM

Acutally power handling isn't halved.  Here's a quote by Dan Wiggins on this topic:

"Lastly, power handling isn't compromised by a factor of 2; it's usually decreased 10-25%. The reason is that rarely are you current-limited by the gauge of the wire, and voice coils are wound concentrically so you still have the entire thermal mass working for you. Just that now all the power is dissipated in a single voice coil (typically two of four layers) so you may end up with an inert, non-conducting thermal mass insulating one side of the voice coil. This does not halve power handling, but can reduce it somewhat."





Posted By: thrice010
Date Posted: May 18, 2006 at 12:53 AM
DVC subs are great for different wiring options but why in the world would anyone power one VC.  IMO...get a 2 ohm stable amp.  Good topic tho




Posted By: bmwpwner
Date Posted: May 18, 2006 at 10:45 PM
good point but here is what you have to keep in mind. when you are selling equipment in a business type atmosphere you want to stock equipment that can be versatile enough to fit a bunch of different customer's needs. and it helps if you can show the customer that the equipment they are buying today will allow them to add to the system without having to get rid of the old equipment first. for example i usually mention that if they are getting 1 sub (maybe for a truck or something that has limited space) then they should choose a woofer with DVC and a slightly bigger amp so that they can later add another sub to the same amp if they move the system to a car or extended cab. then i explain that with the single woofer you can use one VC (4 ohms) and wire that into the bridged setting on the amplifier (mainly because everyone wants the amp in mono) and with 2 subs you can wire them into 8 ohms each and then mono that into the amp. this way they are always getting maximum performance out of the amp and the sub or subs. great solution and it so much easier to teach sales person which brand to sell versus having 4 or 5 different model number in each woofer line.

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"I cannot teach anybody anything, I can only make them think."
-Socrates-




Posted By: thrice010
Date Posted: May 19, 2006 at 9:00 PM
i do agree in the business world, that may be brought up.  I can't say that I havent said that to a customer already but point being...its not the best route.  For people that do want to keep that amp because they dont have the money for another one...that may be just fine :)




Posted By: couchflambeau
Date Posted: May 27, 2006 at 4:51 PM

Are any of the other Thiel Small parameters affected by running only one of two coils?  Mainly concerned on how box calculations would be affected by running only one coil and if the published manufacturers recommended enclosure size would still be valid...?

Good topic, lots of snake oil going around about this....





Posted By: soultinter
Date Posted: June 16, 2006 at 12:42 PM
so how do you "short" the other coil ???????




Posted By: wishboneattack
Date Posted: June 17, 2006 at 9:57 PM
With a screw driver.... posted_image LOL

I just read all the posts on here and laughed intensly. So did anyone get a DVC sub and test the idea? If you buy a DVC sub from any manufacturer there is a pamplet that comes with it and tells you to not hook up one coil in the manner you would both because you will damage the sub and void your warranty... Man it is almost worth buying one from Best Buy and trying it out on a Fosgate. Buy the service plan of course, for when it cooks... I've beenn in the business for 18 years now and can honestly say yes it will damage it. Seen it many times from people hooking them up not knowing the other VC needed to be hooked up too. I like to hear that scraping crunch noise when you push down on the sub. I get a good chuckle everytime.....

Please proceed...

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I may be lost but I am making good time.




Posted By: bmwpwner
Date Posted: June 17, 2006 at 11:32 PM
yep come to my Best Buy and have me install a DVC woofer up for you and i will guarantee it will NOT void your warranty and i can optimize your woofer and your amplifier. i can't believe that anyone (after reading all the above posts) would post an reply claiming that running one voice coil will damage a woofer. also, anyone that knows how to tune an amplifier on a woofer should understand how impedance loads work and what will work and won't work. at our shop we not only install the equipment we educate the customer on how to listen to music and distortion. btw, instead of the crunching sound i like hearing "i know i hooked it up right but the amp keeps shutting off" and that is when we show them why we are paid professionals that understand impedance manipulation and optimization of their stereo (ie amp and woofer(s)). i will say it again, anyone that honestly believes that using one voice coil on a DVC is the best way to ruin the woofer you need to save up a big wad of cash and then take me to the casino because i've been running them that way for 10 years and never seen any evidence of this causing any damage to a woofer or an amplifier. customer's that are not educated on their equipment (and the equipment's limitations) can and will damage equipment until they are taught the correct way to use their stereos -- any really isn't that what we are all here to do? good luck and hope this helps!

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"I cannot teach anybody anything, I can only make them think."
-Socrates-




Posted By: speedstep1
Date Posted: June 18, 2006 at 4:50 AM

hi, need some clarification here.... so can i say if i have a 2ch amp & a DVC, its either -

- bridged e 2ch amp, parallel e DVC & connect, makin it into 4ohm

or

- 2 seperate channel goes to 2 seperate coils, end up each coil is 8ohm??

which is e better option?? thks for e advice in advance.... :)





Posted By: bmwpwner
Date Posted: June 18, 2006 at 7:27 PM

if you are running a DVC woofer then it can be wired to act as the following impedances:

4 ohm (using only one coil)

8 ohm (requires running the coils in series ie run a jumper from + on one coil to the - on the other and using the left over inputs to go to the amp outputs)

2 ohm (parallel both coils)

if you are doing an AB Class amplifier (ie a standard 2 channel that is 2 ohm stable at bridged) then running the woofer as a 4 ohm woofer is the best way in my opinion. remember that when you wire the woofer to the impedance you desire then you must take into account that a 2 channel amp will half that ohm load on the bridged setting.

if you are using a D Class Mono block amp then whatever impedance you put in will be what the amp actually sees. these amplifiers do not half the impedance like AB class amps. in this case then you could wire the woofer in a 2 ohm load (given that the amp is 2 ohm stable) and that will maximize the woofer and the amp.

if you are running 2 woofers on a 2 channel then i would wire both woofers in 8 ohms EACH and then mono into the amplifier for the most bass. if you are looking to have more quality sound then run them in 4 ohms EACH and go stereo (left + and - going straight to left woofer and right + and - going straight to the right woofer) into the amplifier.

i usually try to wire the amp in bridged setting because if i don't then the customer will eventually come back behind me and do it and eventually kill the amp. good luck and hope this helps.



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"I cannot teach anybody anything, I can only make them think."
-Socrates-




Posted By: speedstep1
Date Posted: June 19, 2006 at 5:41 AM

oh my..... i m totally lost now.... hahaha....... posted_image

correct me if i am wrong -

1) with a class AB 2ch amp, if i bridge the 2ch into 1 (ie usin '+' of ch1, & '-' of ch2), it becomes 2ohm output, therefore i need to connect the DVC in parallel (2ohm) ???

or

2) if i only use 1 ch of the 2ch AB amp, & connect to only 1 coil, that means its 4ohm rite? what do i do with the 2nd ch & 2nd coil?

or

3) i bridge the 2ch amp, & connect to only 1coil, whats the effect?

4) i connect ch1 to coil1, & ch2 to coil2, whats the effect?

sorry for askin too much qns... noob here heehee





Posted By: bmwpwner
Date Posted: June 19, 2006 at 10:25 AM

it might be easier if you just post what equipment you have lol. if you have a 2 channel amp and are only using 1 DVC woofer then you want to wire the woofer as a 4 ohm (only one coil) because the 2 channel amp will half that impedance when you put that load on the bridged channel. so if you wire the woofer into 2 ohms and then mono that into the amp it will actually be running at 1 ohm rather than 2. that usually lets the magic smoke out of the amplifier and that is not good.

now hooking channel 1 to one coil and channel 2 to the other coil will work but will not be the most efficient way to do it. technically there isn't anything wrong with doing it that way but you aren't really maximizing anything at that point.

again, the halfing of the impedance only happens on the BRIDGED setting. you don't want to use channel 1 or channel 2 alone. either stereo or bridged is the best way to do it.

if you have anymore questions you can PM me with what equipment you have and i'll try to help ya.

btw, asking questions shows an eagerness to learn so, in my opinion, don't ever be embarrassed by asking questions. good luck and hope this helps.



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"I cannot teach anybody anything, I can only make them think."
-Socrates-




Posted By: speedstep1
Date Posted: June 19, 2006 at 10:16 PM

hi bro,

thks for all e advice earlier!

currently, i have a 2ch rodek amp, stated 'competition series 500W' on e cover, but i still cant find e catalogue or exact model number on the net... & a JBL GT1000 10" bass tube. i am lookin into upgradin to 1x DVC due to the limited space in my boot.

so base on the advice earlier, can i conclude tat for max. efficiency, juz bridge e 2ch into 1, & connect to 1 coil???

thks!





Posted By: Steven Kephart
Date Posted: July 05, 2006 at 11:57 PM

nouseforaname wrote:

 their sub power will be decreased almost in half(30-40%).

Actually it's not quite that bad.  Read my previous post to see why.





Posted By: Steven Kephart
Date Posted: July 06, 2006 at 2:14 PM
I personally don't know.  The above came from my old bosses EE degree and a great deal of experience designing speakers.  Honestly the best way I have found to learn was to search all the car audio forums for Dan Wiggins' technical posts as they are ALWAYS very informative.  Here's some white papers he has written: https://www.adireaudio.com/TechInfo.htm  Also search in this online magazine: https://www.adireaudio.com/TechInfo.htm   He did the "chalkboard" section where people would ask him technical questions and he would answer.




Posted By: camusmuse
Date Posted: July 10, 2006 at 11:05 PM

Great topic!!  I've been arguing this for years as well.  Not a thing wrong with only running one coil, or even running different info to the two coils.  Infinity had a home speaker line called Quantum(this is gonna date me) that ran a watkins dual vc 12" woofer.  One coil was 6ohms the other was 2ohms(I think...been a few years).  They had a nifty passive crossover with what I believe was a special notch filter for the 2 ohm coil to make up for the "peaks and valleys" of the 8ohm coil.  Sure this did goofy things to the overall impedance, but it had amazing bass for two twelves(in stereo). 

If the situation ever presented itself, I'd love to try something similar with a more modern dual or quad vc speaker with active crossover and dsp.  I'd imagine the tuning would be nearly limitless.....and a big PITA, but thats half the fun isnt it?  





Posted By: demo21r
Date Posted: August 15, 2006 at 11:29 PM
not really on subject but.

Here goes not sure if this is right I believe that when I hook 2 dual 2omhs subs up I should have a 1 ohm load ?




Posted By: bmwpwner
Date Posted: August 16, 2006 at 12:15 PM
if you have 2 2ohm DVC woofers and only used one voice coil of each woofer then you would have 1 ohm going into the amp. if the amp is a mono block amp then that would be the perceived impedance.

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"I cannot teach anybody anything, I can only make them think."
-Socrates-




Posted By: INSTALLER_MSS
Date Posted: August 16, 2006 at 8:26 PM
I have worked in high-end shops for quite some time now and have to agree and disagree with the views stated here.  Yes, DVC is nice because of the different options to wire them, but they aren't intended to be used with only one VC.  The reason for DVC was for running multi-sub systems.  There may have been a coupl esubs that suggested running one for bass and one for varied QT, but not nowadays.  You can run one VC at half RMS power yes, but you still should just buy the right amp/sub combination instead of half-assing it.  And also, I don't think you guys who are saying "just use the other VC when you blow one" have actually tried this successfully...at least not for very long.  When you blow a VC it can still damage the other and if it doesn't then it can still "hang up" on the pole when the other is hooked up and used.  In other words it's just not a good idea.  Just because something works, doesn't make it the right way.  You can get an amp to "work" by running 16g speaker wire to the battery for power and ground, but thats not right is it?




Posted By: demo21r
Date Posted: August 16, 2006 at 8:38 PM
I got my subs and amp today and what was 2 single vc 2 ohm subs are actually 2 dvc 2omh subs and i have a 1200 watt class d mono amp capable of 1 ohm now how do I wire them

Rich




Posted By: bmwpwner
Date Posted: August 16, 2006 at 11:30 PM

"And also, I don't think you guys who are saying "just use the other VC when you blow one" have actually tried this successfully...at least not for very long.  When you blow a VC it can still damage the other and if it doesn't then it can still "hang up" on the pole when the other is hooked up and used.  In other words it's just not a good idea. "

actually i have used the other coil and the stereo did fine afterwards. now if the woofer is covered under warranty then by all means swap it out and do it right but if something is way out of warranty or if that model isn't made anmore (which was the case) then if you check the impedance of the unused coil and everything checks out then yes you can use the other coil. again, if anyone says this is an incorrect way to run ANY dvc then i dare say you have fallen victim of learning your craft via book knowledge rather than practical application. and if doing this in the older model dvc or newer ones is incorrect then i would love to see why that is so. i have been doing this since DVC came out and have never seen a problem with running one vc. regardless of anything else this has sparked all kind of responses on this topic. good times.



-------------
"I cannot teach anybody anything, I can only make them think."
-Socrates-




Posted By: INSTALLER_MSS
Date Posted: August 17, 2006 at 9:13 PM
actually my knowledge has come from building award winning competition vehicles at high end shops, not books.  my only book knowledge, as you call it, has come from the MECP certification books.  i'm only victim to hearing the stupidity of half-ass installers that work in junk shops.  and i have over 100 trophies on the counter at work to prove it.  if you read my post correctly you would have realized i said that running one VC can work but it is half assed and not what the manufacturer made it that way for.  also, i never said it always damaged both VCs, i said it can.  and once again i said it CAN hang up on the pole piece, not that it always did.  to me, it sounds like you guys need to read a book...or at least not do half ass work and think that you are right.  but you know, they say never underestimate the power of stupid people in large groups, right?  Not intended toward the people here that know what the hell they are talking about or those who were never in this.  please don't waste any more of my time until you get some more education and experience there, amature.




Posted By: INSTALLER_MSS
Date Posted: August 17, 2006 at 9:25 PM
i never said it was wrong in the sense that it would cause damage to the sub.  i mean that it's not how the manufacturer intended it to be used.  if you ever look at the specs for any woofer, it doesn't say: hook it up this way at this power, in this application with one VC, OR if you use both use it this way instead.  all i'm saying is that it's half-*** and ****** up to sell a customer a piece of equipment and then only hook up half of it for them.  sell them the right stuff to begin with.  if they come in with the wrong doodie, then try to help them get the right woofers for the amp they have or vise-versa.  if they don't want to dish out the cash (which too many customers don't want to) then hook it up one VC.  once again...i'm not saying it won't work or that it'll mess things up...it's just not the way it should be.




Posted By: bmwpwner
Date Posted: August 17, 2006 at 9:43 PM

HOLD UP BABY! calm down and take one of those pills. only people that question their knowledge get that upset that quickly sweetums. the reason there aren't any diagrams in the woofer connection guide that comes with each speaker is because (i'm ASSUMING - place your quote/joke here ASS-U-ME) that any installer with a couple of months of experience should know that you can use only one vc. that is great that you build these huge "competition" vehicles and it is your opinion that we are "half-assing".

i work for the largest electronics retailer in the world and i have 10 years of apprenticeship under my belt at a custom shop. you also need to understand that for those of us in the world of retail (big box stores ie publicly traded company) that we carry products that fits the majority of the general publics needs. a dvc woofer makes more sense than carrying 5 different model numbers that only differ in impedance loads. again i respect your opinion on product and/or installation suggestions but please do not call me a half ass installer unless you have taken my work apart and can back up your claim. i have been in the business a long time and i still learn something new everyday but on this fact i stand firm and if i'm wrong i am the luckiest guy in the world.

**on a side note i am MECP certified but i don't really thinks that makes a bit of difference. good luck and hope this helps.



-------------
"I cannot teach anybody anything, I can only make them think."
-Socrates-




Posted By: INSTALLER_MSS
Date Posted: August 17, 2006 at 9:55 PM
don't come at me sideways.  i didn't insult you so give me the same respect.  i said that its different for certain applications.  i too have worked for a huge chain store and that reason you just gave me has made me go back to sole-proprietor custom shops.  i don't know about your work nor do you of mine.  i have 7 years experience in custom work myself so i know how things go.  i care more about making the customer happy than making the store a dollar.  i have no beef bmw unless it gets brought my way first.  people here should read doodie more carefully and try to understand what others are saying before they pop of at the damn mouth.




Posted By: haemphyst
Date Posted: August 18, 2006 at 9:01 AM
Whoa, installer_mss... WHOA!!!

Dude, you need to chill out. I did read your post, and I felt personally attacked with your first post. I personally don't like being told I'm wrong, especially when I know I'm right. You are new here, at the12volt, and (to borrow your phrase) you have no idea who I am, or my credentials. You may be an installer with much experience, (it is not for me to say otherwise, I don't know you) but I personally know two (actually 1 and ½ - one full-fledged, one third year apprentice) loudspeaker designer/engineers at Harman International in Northridge. When they say "There is nothing wrong with running one voice coil", I think I can fairly safely bring that information here. There is no "grain-of-salt" involved.

Steven Kephart worked for Adire Audio, one of the most highly respected names in high-end audio - does the name Dan Wiggins ring a bell? Did you by chance read the paper by Dan that I know was linked to early on in this thread? If you did, and you are still questioning the validity of the viability of only running one voice coil, I have to wonder what kind of car you're driving - gotta be an H2, cause your head wouldn't fit in anything smaller...

For your information, I have seen MANY times in the past, an owners manual from several manufacturers, (all the names escape me presently, but I can say with certainty, that I had two Infinty Pro 12's with three sets listed...) an actual listing of THREE sets of Thiel-Small parameters - one with one voice coil, and one series and one parallel wiring. Granted, it is not common-place today, most everybody will use both coils, because it's "better"... (lower impedance gets more power from the amp, so it MUST be "better", right?)

I "have no beef" with you, either, but I can tell you that no matter HOW much you think you know, if you listen with an open mind, you'd be very surprised how much you can learn. Calm down, pay attention, and learn a little bit. You will find that you are NOT always right, and it's an eye-opening experience!

Welcome to the12volt, I'm sure in your experience, you have gained MUCH knowledge, hang out here, and share some, but always know that as much as you might actually know yourself, there are others out there that can teach you even more. You have been learning your whole life, and those SAME types of people were the ones teaching you all along, and there are more out there... We try to be a mature forum for professionals and amateurs alike, and we (generally) all show respect to all the other members here. Please do the same, and one of the ways we all show that, is refraining from profanity.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: demo21r
Date Posted: August 19, 2006 at 12:05 AM
Here Here
But now back to shorting the 2nd VC or putting in a resistor what is the correct way I have 2 2omh solo baric kickers and a 1200 watt class D mono amp capable of running 1 omh I under stand use 1 VC Each in series but what do I do with the other 2 VC's

It does say Rookie next to my monogram




Posted By: stevdart
Date Posted: August 19, 2006 at 1:39 AM

Not answering for anybody else, but here's my thoughts on this:  it's a dangerous habit to get into, thinking and saying that you'll just lose 10% of total power handling using one voice coil, as if it's a perfectly acceptable option for the mainstream and fundamentally-challenged user.  Unless you are working up a very advanced setup, both coils should be used...unless the manual specifically states otherwise.  Here is a typical Kicker manual, and here is one from Alpine.  The first specifically forbids using just one coil, and the second says the same thing by way of illustrations...a one-coil "option" is omitted, which makes it forbidden by omission.  

Most subwoofers that I know about have availablity in more than one coil configuration.  And add to that the fact that we have both mono and two channel amplifiers to choose from.  Which is to say there is no reason, other than something esoteric and far from mainstream, to put a system together where you are forced to use only one coil.  It's called an "oops".  Or, if it's a salesman in a car audio shop selling a customer a mismatched system with the advice that using one (of two) coils is a viable option, it's misleading (if it doesn't say the same thing in the manual). 

The proper thing for the professional in the industry to do is to put together a proper package of goods.  The proper thing for the end user to do is to wire subwoofers according to the instructions contained in the sub's manual.  As was stated above, just because something can be done doesn't necessarily mean it should be done.



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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.




Posted By: demo21r
Date Posted: August 19, 2006 at 8:48 AM
Mine was the (oops!) I ordered the wrong one so looks like this one will be expensive and I will order the 4 ohm version to make it right. thank you all I have learn alot and will continue to read on and watch the forum for info.

Thanks for the info as sales rep was of no use




Posted By: demo21r
Date Posted: August 20, 2006 at 12:03 PM
Is this amp considered a good amp to drive 2 2ohm subs

RMS Power Output:     750W x 1 @ 2 Ohm
Peak Power Output:     1500W x 1 @ 2 Ohm
Birdged Output:     1210W x 1 @ 1 Ohm
Signal To Noise Ratio:     100dB
Frequency Response:     5Hz-250Hz
Input Sensitivity:     100mV-16V
Bass Boost:     0-18dB
Built-In Crossovers:     Variable 24dB
THD @ 4 Ohm RMS Power:     0.10%
Ohm Load Stability:     1 Ohm
Low Level Input:     Yes
Built in Cooling Fan:     No
Bass Control Knob:     Yes





Posted By: INSTALLER_MSS
Date Posted: August 20, 2006 at 9:59 PM
haemphyst, i have to say i have a lot of respect for you.  i admit a said some strong words that probaly should have been toned down, but the way you approached it deserves respect.  this as i recall is a thread asking opinions.  i don't think running half a woofer is the best idea but i will not deny that it will work.  thank you for the way you responded...some people here (including me actually) should follow suit.  sorry if i offended anyone...besides bmwpwner...lol, j/k, but stop the name calling.




Posted By: INSTALLER_MSS
Date Posted: August 20, 2006 at 10:01 PM
are they DVC 2 ohm subs or single VC.  and what brand of amp?  what is the rms handling of each sub?




Posted By: demo21r
Date Posted: August 20, 2006 at 10:59 PM
The Amp is a concept CD 1210
The Subs are Kicker 04S12L7 D2 12 Inch
    * 12" Kicker L7
    * Dual 2 Ohm Impedance
    * RMS Power Handling 750 Watts
    * Peak Power Handling 1500 Watts

I also have the choice of a
Brand:     Concept
RMS Power Output:     1150W x 1 @ 2 Ohm
Peak Power Output:     2100W x 1 @ 2 Ohm
Birdged Output:     2410W x 1 @ 1 Ohm
Signal To Noise Ratio:     95dB
Frequency Response:     5Hz-250Hz
Input Sensitivity:     100mV-16V
Bass Boost:     0-18dB
Built-In Crossovers:     Variable 24dB
THD @ 4 Ohm RMS Power:     0.10%
Ohm Load Stability:     1 Ohm
Low Level Input:     Yes
Built in Cooling Fan:     No
Bass Control Knob:     Yes

Still not sure please help these are for my sons 16th Birthday But if really sounds good i might geta set also
Rich





Posted By: demo21r
Date Posted: August 20, 2006 at 11:09 PM
His head unit is a Vintage Poineer DEH 47 front speakers are 3.5 blauplunkt rears are 6x9 coax blauplunkt

I allready have the Kicker subs




Posted By: INSTALLER_MSS
Date Posted: August 20, 2006 at 11:23 PM
they should match up fine...you won't get 100% power from the amp...but it'll give enough if those specs are accurate.  besides, it won't get as hot running at 2 ohms instead of 1 ohm so you'll be able to jam it for long periods of time with no problem.  make sure you don't have any voltage drop below 12 volts...11.5 min.  if it does, it can damage the amp.  use at least 4 guage power and ground or bigger and make sure you have a good ground.  an extra battery or couple of capacitors wouldn't hurt to be honest.  especially if its a small car or mini truck.  there are various forum topics you can read that should be quite helpful.




Posted By: demo21r
Date Posted: August 20, 2006 at 11:34 PM
Should i go ahead and get the the cd 1210 or the second amp the CD2410

Brand:     Concept
RMS Power Output:     1150W x 1 @ 2 Ohm
Peak Power Output:     2100W x 1 @ 2 Ohm
Birdged Output:     2410W x 1 @ 1 Ohm
Signal To Noise Ratio:     95dB
Frequency Response:     5Hz-250Hz
Input Sensitivity:     100mV-16V
Bass Boost:     0-18dB
Built-In Crossovers:     Variable 24dB
THD @ 4 Ohm RMS Power:     0.10%
Ohm Load Stability:     1 Ohm
Low Level Input:     Yes
Built in Cooling Fan:     No
Bass Control Knob:     Yes




Posted By: bmwpwner
Date Posted: August 21, 2006 at 8:41 AM

if you are using that radio on the 3.5" and 6x9s then here is something to try from the radio. i think that radio has a FIE (front image enhancer) function. if you turn that on for the front speakers then you can use it kind of like a crossover and set it to the highest setting (i think it is 250). if you are using an external amp then it won't matter to much since most amps has at least a high pass filter crossover built in. it probably wouldn't hurt to put some bass blockers on those front speakers.

as far as the woofers and sub amp go i would wire them into a 4 ohm load (series the 2 coils) and i would put them into stereo on the amp. the reason i am saying wire them in stereo is because every 16 year old i have seen wants to crank on the system as much as they can and then wonder why they blow the woofers or the amp. if you put the system in stereo it will run the amp easier and have a lighter load on the subs. i would also tune the system so that everything is as low as possible and still sound clean. power isn't what kills equipment it is about how you operate the equipment and how you listen to it. when we have younger customers in our shop we spend almost as much time educating them on what not to do as we spend installing the system. this is better for us because if do something to the system that we told them not to then when it breaks they know they are at fault. we call this a "bought lesson". i would hate to see your vehicle fall into this category.

btw, i would like to say i didn't mean to offend installer_mss by calling him sweetums. i don't consider this to be name calling because i merely wanted to lighten the mood around his tone. i also like the name sugar breechez (but you have to say it with a southern draw). that is a little pet name i have for nouseforaname at our shop and he loves it. lol, all good and keep learning fun sugar breechez.

good luck and hope this helps.



-------------
"I cannot teach anybody anything, I can only make them think."
-Socrates-




Posted By: INSTALLER_MSS
Date Posted: August 21, 2006 at 11:54 AM
it might not have FIE if it an older pioneer.  but if you do have that feature i would use it.  do use the bass blockers if you use the HU to run the speakers, and not if you use an external amp.  i would use an amp at high pass myself because you get a cleaner sound from an external amp than a HU and a lower distortion level.  it costs a little more do buy two amps but you will hear the difference and be glad that you did.  bmw pretty much nailed it on the sub/amp thing.  run it at 4 ohm stereo and you'll have enough power to kick up some bass and not run the amp into the ground doing so.  if you run it like this and use proper installation techniques you should never have any problems with the amp unless there is a manufacturer defect of coarse...which is not likely.  besides, those concept amps i've noticed don't like to be run full throttle for long periods of time, but at 4 ohm stereo it should be fine.  and lastly, no don't buy the bigger amp, you don't need more power than the first amp.  if you don't mind me asking...what kind of vehicle is this all going in?




Posted By: demo21r
Date Posted: August 21, 2006 at 9:19 PM
It is going in a 1994 OLDS cutlass ciera 4dr I have used rubberized under coating inside the trunk to help reduce noise and vibration I have 1/0 power and ground wire and using monster 16ga speaker wire.




Posted By: bmwpwner
Date Posted: August 21, 2006 at 9:56 PM
that pioneer should have FIE on it. that is last years model but it is a wal-mart radio. i think the only difference between the deh-p47 and deh-p4700mp is the display colors and the 47 may not have mp3 playback. anyway, i would probably put bass blockers on the 3.5" speakers either way you go personally. the FIE would be a cheap way to go especially if you don't want to have to go back into the install to put the blockers in. i like to safe guard the smaller speakers as much as possible especially when the customers are young. good luck and hope this helps.

-------------
"I cannot teach anybody anything, I can only make them think."
-Socrates-




Posted By: demo21r
Date Posted: August 22, 2006 at 10:27 PM
I'll let you know How it goes.




Posted By: bmwpwner
Date Posted: September 04, 2006 at 6:58 PM
hey guys, this is a little off the subject but i was wondering what a good program would be to do the drawings for schematics. i am wanting to design a sheet for alarms and some other basic things for some co-workers and i like the way the relay diagrams and stuff look on this site but i don't know which program would have everything i need for mobile electronics. any suggestions for a trial version so i can sample the program prior to buying it would be great. thanks in advance.

-------------
"I cannot teach anybody anything, I can only make them think."
-Socrates-




Posted By: demo21r
Date Posted: September 04, 2006 at 11:10 PM
Well I got it all hooked up went with Kicker 1200.1 with 2 12 solobaric dual 2ohm voice coils and wired to 2ohm and it sounds great does not seem to be pushed to hard and best of my 16 yr old likes it and is happy with the system

Thank you all for all the info will continue to read on

Rich posted_image posted_image




Posted By: mike_2127
Date Posted: October 01, 2006 at 4:18 PM
I don't understand why you would do that. i guess if you don't have a choice, or the customer brought the speaker in, you could do that but otherwise just bye the right speaker/speakers. i think the wiring options are meant for using both voice coils on a dual voice coil speaker.




Posted By: pwuthedon
Date Posted: October 01, 2006 at 8:42 PM
not a good idea




Posted By: murdakillemall
Date Posted: October 28, 2006 at 1:37 PM

Just to add to this topic, I had a question...

I'm trying to maximize my usage of components. I already have two 4-ohm 12 inch subs, single voice coil, wired at 2-ohm on a mono amp. Eventually, I'll be replacing the speakers with something new. I wanted to buy two 4-ohm dual voice coil speakers so that I can be variable with the wiring options. Now, the amp is not 1-ohm stable so my wiring options were limited. To maximize the amp power, I would have to run a 2-ohm load. Later in life (when I get more money) I will either get an additional amp that is the same as the current one (basically using 2 mono amps) or one 2-channel amp that is stable at 2-ohms.

So, the question is, with the new speakers and the current amp, would it hurt to run one coil from each speaker in parallel with the other speaker to get a 2-ohm load on the amp?





Posted By: addicted
Date Posted: October 31, 2006 at 11:12 PM
4ohm. dvc. subs, using 1vc from each wired in parallel, bridged 2 channel amp. that would be a 2ohm load from the woofers so the amp "see's" 1ohm in mono state correct?




Posted By: addicted
Date Posted: October 31, 2006 at 11:14 PM
the amplifier is stable to 1/2 ohm.




Posted By: addicted
Date Posted: October 31, 2006 at 11:19 PM
and if i wire each vc. in parallel that would give me a 1 ohm. load. the amplifier would "see" 1/2 ohm. load is that not safe? would my dynamic headroom be at its peak? (orion 250 hcca a classic) i would think not very much playing time before cooking my amp.




Posted By: camusmuse
Date Posted: October 31, 2006 at 11:34 PM

how many ohms are each coil?  two subs(four coils)....if they are 4ohms each, then you can go 1 ohm(parallel), 4ohm(parallel/series combo), or 16ohm(series).  You can run that HCCA at 1ohm mono but it will run HOT and youll need active cooling(and one hell of a charging system for the unregulated PS).  for a daily system might be better running stereo at 2 ohms per channel.  I had two of these years ago and ran one mono at  2ohms and it was amazing(two orionxtr 12's..nothing special), then the other amp for my highs(Peerless 6.5, orion nt4 and nt1 all at 4 ohms)....little low on volume, but sounded fantastic.  Plus two 250 hcca's lined up with the "spacer" just looks cool....





Posted By: addicted
Date Posted: November 01, 2006 at 5:57 PM
4 ohm. vc's, and i have an 12 volt ocsillating fan on the amp, not the carshow type set-up, but i need to be efficient while satisfying the bass need. 2 ohms per channel would take me out of mono mode. shouldn't a signal be in mono for these subs? (15 kicker comp.cvr4ohm.) i think i will try that. see how i sound, i do need a power friendly system at times. hcca's are current hungry.




Posted By: 1lowgalant
Date Posted: November 02, 2006 at 7:09 AM
the amp doesn't "see" a 1/2 ohm load, the given load is shared between both sets of rails inside the amp. regarding the subs requiring a mono signal, a sub doesn't know what kind of amp it's hooked to. stereo and mono are conditions involving the way the channels are wired for output. a subs only concern is handling the supplied power without going passed it's thermal limits. the lower the supplied impedance, the harder the amp has to work resulting in ineffecient power due to being lost as heat.

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Whatever you do, DO NOT let the white smoke leak out of the wires.....




Posted By: cabsnow
Date Posted: November 12, 2006 at 7:17 PM
I have a Kenwood Kac-7202 amp and a Alpine Type R SWR-1242D!
What is the proper way for me to hook this up. Thanks for the help in advance!




Posted By: KarTuneMan
Date Posted: November 13, 2006 at 12:15 AM
GOOD LORD MAN.....buy another sub....!

-------------




Posted By: cabsnow
Date Posted: November 13, 2006 at 6:18 AM
KarTuneMan wrote:

GOOD LORD MAN.....buy another sub....!

May i ask why i should buy a new sub?




Posted By: sin0cide
Date Posted: November 25, 2006 at 1:41 AM

1lowgalant wrote:

t the lower the supplied impedance, the harder the amp has to work resulting in ineffecient power due to being lost as heat.

I am confused... wouldn't the amp have to work harder if it had "more" resistance? resulting in less output or maybe heat/ energy loss?





Posted By: fatgotti
Date Posted: January 21, 2007 at 11:13 AM

I use this site everyday for trouble shooting and this might be the best info i have ever seen. I have got a million ideas in my head now



-------------
Fatgotti    Yeah my name is John and I am FAT!! YEAH BABY




Posted By: jkwylde
Date Posted: January 22, 2007 at 10:26 PM
Definitely ok to run only one - correct procedure is to short the terminals of the unused coil, which provides electromagnetic resistace - IE allows you to Dampen the other coil. You may also wire a resistor or 500klog pot between the unused coils speaker terminals.

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bangin old school since it was new




Posted By: andy wehmeyer
Date Posted: January 30, 2007 at 6:26 AM
More resistance doesn't cause the amplifier to work harder. Think of low resistance as air and high resistance as water. If you flap your arms around in the air, you won't go very far unless you attach a bunch of feathers or a couple of pieces of plywood and have really strong arms. However, if you jump in the pool and flap your arms around, you'll go. The difference is that the water provides a much greater resistance to the motion of your arms than the air.

-------------
Andy Wehmeyer
Product Marketing Manager
Harman Consumer Group
Mobile Systems Division




Posted By: sparky3489
Date Posted: February 20, 2007 at 9:08 AM

jkwylde wrote:

Definitely ok to run only one - correct procedure is to short the terminals of the unused coil, which provides electromagnetic resistace - IE allows you to Dampen the other coil. You may also wire a resistor or 500klog pot between the unused coils speaker terminals.

This is so obsurd. When you short out one of the coils you create a elctromagnetic resistance (or brake) by doing so as you say. This is a bad idea.

Since a speaker is considered a motor, try this. Get two 6 volt DC motors. Connect their shafts with wire insulation. Supply 6 volts to one motor, wait a second and short the other motor. What happens? The RPM's of the motor system slows down. It also creates more heat as one moter is trying to overcome the resistance and the other motor is trying to keep from moving.

This is also what happens to the DVC with one coil shorted. It makes the overall movement of the cone have resistance to move and creates more heat. I think everybody can agree that more heat is a bad thing.

I also agree with another poster that only using half of a DVC will be able to only handle half the power. DVC were made with both coils, tested with both coils and should have both coils used.

If you need 4 ohm, just get a 4 ohm SVC. Period. Why risk it?

A.A.S. in Electronics/Industrial Electronics with 25 year as an electronics technician, Peavey MediaMatrix certified





Posted By: krazykaz
Date Posted: March 14, 2007 at 2:33 PM

I have 2 DVC 4 ohm subs.  They each handle 400 watts RMS total.

The only way I have ever seen this set-up is either in parallel or series/ parallell  I would end up with either a 1 ohm or 4 ohm load.  Even the12volt.com website says thats the two ways to hook them up. 

This forum is implying that I could hook up 1 4ohm VC from each sub into a 2 ohm load?  I would then only use 300 watts of power?  How would this give me the same SPL as hooking up all 4 coils with twice the power?  That would be like getting the same power out of a V8 by only running four of the cylinders.

Please explain.





Posted By: Steven Kephart
Date Posted: March 14, 2007 at 8:21 PM

andy wehmeyer wrote:

More resistance doesn't cause the amplifier to work harder. Think of low resistance as air and high resistance as water. If you flap your arms around in the air, you won't go very far unless you attach a bunch of feathers or a couple of pieces of plywood and have really strong arms. However, if you jump in the pool and flap your arms around, you'll go. The difference is that the water provides a much greater resistance to the motion of your arms than the air.

Andy, Welcome to the forum!  I hope to see you around often to offer your vast knowledge.





Posted By: Steven Kephart
Date Posted: March 14, 2007 at 8:27 PM
krazykaz wrote:

I have 2 DVC 4 ohm subs.  They each handle 400 watts RMS total.

The only way I have ever seen this set-up is either in parallel or series/ parallell  I would end up with either a 1 ohm or 4 ohm load.  Even the12volt.com website says thats the two ways to hook them up. 

This forum is implying that I could hook up 1 4ohm VC from each sub into a 2 ohm load?  I would then only use 300 watts of power?  How would this give me the same SPL as hooking up all 4 coils with twice the power?  That would be like getting the same power out of a V8 by only running four of the cylinders.

Please explain.


As far as I know, nobody ever said you would get the same amount of output.  That isn't the point of this discussion.  The point is that you won't cause any damage by doing this as long as power limits are observed.  And it offers a way of electrically tweaking your Qtc.





Posted By: Steven Kephart
Date Posted: March 14, 2007 at 8:52 PM
sparky3489 wrote:

jkwylde wrote:

Definitely ok to run only one - correct procedure is to short the terminals of the unused coil, which provides electromagnetic resistace - IE allows you to Dampen the other coil. You may also wire a resistor or 500klog pot between the unused coils speaker terminals.

This is so obsurd. When you short out one of the coils you create a elctromagnetic resistance (or brake) by doing so as you say. This is a bad idea.

Since a speaker is considered a motor, try this. Get two 6 volt DC motors. Connect their shafts with wire insulation. Supply 6 volts to one motor, wait a second and short the other motor. What happens? The RPM's of the motor system slows down.


Unfortunately the previous link explaining your concerns is broken.  Here's a new link that will explain: https://www.adireaudio.com/Files/RDOOperation.pdf  As you can see, the "resistance" (showing up as electrical dampening or QES as jkwylde mentioned) can be useful.

sparky3489 wrote:

It also creates more heat as one moter is trying to overcome the resistance and the other motor is trying to keep from moving.

This is also what happens to the DVC with one coil shorted. It makes the overall movement of the cone have resistance to move and creates more heat. I think everybody can agree that more heat is a bad thing.


There isn't enough extra heat generated to cause concern.  Here's a quote from this tech paper explaining this https://www.adireaudio.com/Files/DualVoiceCoilDrivers.pdf:

"Take the "worst case" situation. You wire the two voice coils out of phase. At first, you think one coil is trying to push forward, the other backward, and suddenly the system tears itself apart, right? Nope. What happens is that one coil sets up a dynamic field. Let's say, for clarification, that coil 1 generates a signal to push the diaphragm forward. Since coil 2 is wired in opposite phase, it sets up a dynamic field to push the diaphragm backward. Net result is that the two magnetic fields CANCEL themselves out! That is, the dynamic field that's pushing on the static field from the magnets is ZERO. The field from coil 2 adds to the field of coil 1 in such a way that the net field is zero. Much like adding a two sine waves of the same frequency that are shifted by 180 degrees.

This is the SAME basic principle with shielded drivers that use bucking magnets. Use a field of the opposite polarity to cancel the original field out. If the driver's motor magnet has a given polarity, use the bucking magnet to introduce a field of opposite polarity, so that the two fields cancel themselves out. Net result is no field.

So, when we run two different signals to the voice coils, what we find is that the magnetic fields of the two combine to generate a net TOTAL field that interacts with the static field of the magnets. The two voice coils NEVER fight each other in a physical way; it's all in the magnetic field. 

Now, you might say, what about the increase in heat? After all, most subwoofers rely on the conversion of electrical power to acoustic power to lower the dissipation in the driver, right?

Again, wrong. Look at the parameters of a typical subwoofer. Look specifically at N0 (eta naught). This is the parameter that gives the electrical-to-acoustical power conversion efficiency of the driver.

This number, for most dynamic cone subwoofers, is less than 0.5%. In a FEW cases, it may be as high as 3%. But, for the most part, you'll see N0 well below 1%.

What N0 represents is the percentage of electrical power that's transformed into acoustical power. For example, let's take a driver with an N0 of 1%. Apply 100W to the driver. Of the 100W electrical power delivered, 1%, or 1W, is converted to acoustic power (1%). The other 99%, or 99W, is converted to heat.

Look at a typical dual voice coil sub, such as Shiva. It's N0 is ~0.4%. This number is VERY comparable to other 12" DIY high-end subs out there, and represents a driver with an 88 dB SPL rating.

Now, apply 300W electrical power. Wire the voice coils in parallel, in the same electrical phase. We'll get our acoustical output, or (300 * 0.004) 1.2 acoustical Watts of power out. The other 298.8W of electrical power is dissipated as heat.

 Now wire the two voice coils out of phase. What will happen? Well, we know from the above that the two magnetic fields from the voice coils cancel each other out, so there's no net cone motion. Thus our acoustic power output is zero (can't have any, if the cone doesn't move).

That means ALL the power is dissipated as heat within the driver. How much? 300W. Compare this to the situation where the two voice coils are connected in the same polarity: 298.8W. Net difference? 1.2W of dissipation. In essence, you will cause exactly 1.2W of extra power dissipation in the system by crosswiring the voice coils.

Now, is that 1.2W extra heat going to be a problem? Most likely, no. If a driver is rated to handle 300W, chances are it's not going to have a problem with 301.2W. 400W, sure, but a 0.4% increase in power dissipated? Well, the temperature of the voice coils may raise another 0.1 degree C, but that's about it.

Anyway, the net result is that the increase in heat from dissipation is essentially zero. The one area of consideration is that self-cooling of a driver is reduced when motion is reduced. So the driver can handle the out-of-phase situation for a little while, but because of the reduced cooling, heat will build up faster."





Posted By: sparky3489
Date Posted: March 29, 2007 at 10:09 PM
I still disagree. What a paper says and what has been performed and measured are two different things.




Posted By: Steven Kephart
Date Posted: March 31, 2007 at 2:34 AM
Not in this case as nothing discussed in the paper is theory.  But you can decide to believe what you want.




Posted By: b1kshad0w
Date Posted: April 08, 2007 at 8:10 AM
I owned some Type-R Subs and it said to make sure you hook up both coils. I personaly would be wized if an installer only hooked up one coil of my subwoofer. The last time I made the mistake of letting someone else hook up my system (Best Buy) they put my subwoofer crossover on high pass!




Posted By: haemphyst
Date Posted: April 09, 2007 at 10:57 AM
sparky3489 wrote:

I still disagree. What a paper says and what has been performed and measured are two different things.

Sparky, did you even LOOK at the paper, and read the whole thing? That paper was written by Dan Wiggins, of Adire Audio. Not EXACTLY the kind of guy to go about spewing crap... If you are thinking that this paper is wrong, where are YOUR supporting documents, papers, webpages... whatever, supporting the validity of YOUR experiments, using SPEAKERS, not MOTORS. Yes, an electromechanical MOTOR will behave as you describe, and while in the most basic of terms, a loudspeaker is little more than a motor, they do not behave the same way. I've already done all of your research for you... Read on.

For YOUR theory to hold water, you would need a motor with two distinctly and electrically separate motor windings on the SAME ARMATURE, they must be immersed in the SAME MAGNETIC FIELD... This is the same as a DVC woofer - two motor windings (coils), on the same armature (former), with the same magnetic field (gap), working on the same load (cone).

Let's say, to analogize your example of two motors connected by the same shaft, that you put two SVC woofers face to face (with a spacer), and we'll use PP cones, to minimize any air leakage through the cone, we'll seal the edges and holes of both baskets (to prevent leaks). The air mass between the cones will be a bit springy, but so is the wire insulation in your example.

Now that we have done this, run a signal into one of the woofers. You will have an output from the backside of the OTHER woofer, correct? Any arguments so far? Now, short the voicecoil of the UNDRIVEN woofer. What will happen? Output will drop, right? This is the SAME thing as the powered motor in your example, being slowed slightly by the electrically shorted motor. Will there be more heat generated in the driven voice coil? Yes, but as the paper by Dan states, and in the case of a woofer with an n0 (eta null) of .4%, or an 88dB sensitivity, somewhere less than .4% of the power input will be additional heat. (Because it is still making output, right?)

One more hole in your theory: Electric motors are FAR, WAY, DRASTICALLY, PAINFULLY more efficient at converting electrical power to horsepower power than a loudspeaker "motor" is. They start around 75% efficiency, NOT (up to) 3% as in a loudspeaker's case... I am getting all of my math from this paper, and it's information will be pretty much the same anywhere you look (it was when I looked...) You are trying to place "motors" with two DRASTICALLY different work efficiencies into the same "efficiency basket". They MUST be kept on the same playing field! Again, read on.

Let's use a motor with a nameplate rating of 1HP, (about 1000 watts input power) to keep it simple.

1000 watts input generates 750 watts (the 1HP rating) output, with 250 watts being generated as heat in the motor windings.

250 watts is ALL THE MOTOR WINDINGS ARE DESIGNED TO TAKE. If you overload that motor, or captivate the motor shaft, to keep it from turning, now there is MORE power being wasted in the windings, in the case of a locked shaft 4 TIMES or 400% of the motors safe thermal rating, (or ALL 1000 watts posted_image ) NOT 100.4% of a loudspeaker's "shorted" power dissipation, of (if we use a 1000 watt woofer, for even playing field) 1004 watts, dissipated from a coil rated 1000 watts... So:

shorted motor, rated 250 watts, dissipating 1000 watts
or
shorted woofer, rated 1000 watts, dissipating 1004 watts

Which will fail sooner? The 400% overpower situation, or the .4% overpower situation? I think you'll understand better now. During normal operation, ALL THE POWER BEING APPLIED IS ALREADY BEING TURNED INTO HEAT in a loudspeaker - (almost) 100%. In an electric motor, only 25% is being turned into heat - the remaining 75% is being converted to rotational energy to DO SOMETHING.

I'll put it to you this way. Your ideas are wrong. Dan's paper is right. Read the whole thing, and try to learn something. Everybody here learns a little something new, everyday, and you could too, if you would open your mind to it.

(AAS... uh, huh... Read, and contribute something helpful... THEN I'll believe you have an AAS with 25 years or whatever you claim...)

-------------
It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: sparky3489
Date Posted: April 11, 2007 at 2:16 PM

Hmmm. I have to admit I underestimated some facts and figures. I have a hard time getting my mind around odd circumstances such as this as I'm as stubborn as they come. I was always told to NOT run one coil by several respectable people for the very fact of inefficiency, less power handling and that it changes the T/S parameters of the sub. Is this true or false?

This also brings up other questions:

Why even run one coil and short the other? Why not get the right sub for the job in the first place?

Does the power handling get split between the two coils of a DVC? I had always thought so.

Stubborn, but willing to learn.





Posted By: haemphyst
Date Posted: April 11, 2007 at 5:12 PM
sparky3489 wrote:

Hmmm. I have to admit I underestimated some facts and figures. I have a hard time getting my mind around odd circumstances such as this as I'm as stubborn as they come. I was always told to NOT run one coil by several respectable people for the very fact of inefficiency, less power handling and that it changes the T/S parameters of the sub. Is this true or false?

No, you are absolutely correct, the TS parameters WILL change, but only the mechanical parameters, Cms, specifically. It will go down, affecting the Qts of the driver, usually lowering it, allowing for use in a larger enclosure. Nice, so you can tune (potentially) lower, especially in the case of a vented enclosure. As far as efficiency, I don't think the No (eta null) changes, so the efficiency doesn't change JUST by not running one of the voice coils. Once the second coil is DAMPED, be it with a short or a resistance, yes, the efficiency will drop by a small amount (I think the number is actually 1.5dB with a shorted secondary). Also the efficiency will drop MORE, the LOWER the resistance placed on the second voice coil.

sparky3489 wrote:

This also brings up other questions:

(It always will, won't it?)

sparky3489 wrote:

Why even run one coil and short the other? Why not get the right sub for the job in the first place?

Well, running one coil and shorting the other is an extreme. Another nice part of having a second voice coil is you can tune the woofer for the enclosure, instead of the other way around... If your box ends up too large, you can install a potentiometer on the secondary coil, and tune the woofer to the enclosure. (once tuned, you can insert a fixed resistor of the appropriate value and leave it there permanently...) I even went so far as to build a "reverse crossover" - an RLC network with a low impedance peak, which allowed me to tune ONE CENTER FREQUENCY out of the response of a VERY peaky system. Worked like a champ. Effectively it was a "one band, passive, parametric EQ".

sparky3489 wrote:

Does the power handling get split between the two coils of a DVC? I had always thought so.

When both coils are powered, yes. When only one coil is powered, the THERMAL MASS of the voicecoil and former hasn't changed, has it? The thermal mass of a 1000 watt voice coil, whether SVC or DVC, will only take 1000 watts, ever. Once you pass that 1000 watt range, you will be rapidly moving into a meltdown territory. This means only that now the current supplied to the woofer will be the major determining factor. Because the thermal mass is the same, that means it will take pretty much the same amount of power, right? Current limitations now apply, because a DVC woofer, rated 1000 watts, the manufacturer is expecting 500 watts per coil, so they only provide the voice coil with a gauge of wire rated for 500 watts at THAT impedance. (Actually for a respectable manufacturer, (i.e. NOT AudioBahn) it's a bit more than that, for safety margin... but BASICALLY that's correct)

In our 500 watt case, (at 4 ohms) that would be approximately 11A. If properly cooled, and ONLY as an an example, an 11A rated wire SHOULD BE ABLE to take 14 to 15 amps or so for short periods of time, (i.e. dynamic power) providing somewhere in the vicinity of around 780 to 900 watts - this is our derating factor - about 10 to 22%, give or take.

Now, because the woofer is not powered at that level all the time, music being the dynamic animal that it is, and the voice coil being cooled simply by moving (remember, dissipating around 499.6 watts already?), the actual de-rating is around 10-20%, as per Dan Wiggins (again, of Adire). Me? I de-rate 25-30%, but that's just me.

sparky3489 wrote:

Stubborn, but willing to learn.

Me too... But that's what makes this such a SUPER forum. I learn new stuff ALL THE TIME, and we (they) are always willing to help.

P.S. Sorry about the AAS jab... I have no idea of your CV, and I shouldn't have judged.

-------------
It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: sparky3489
Date Posted: April 12, 2007 at 11:30 AM

Just for clarity...

If the the power handling is halved if only one coil is used since each coil is 500 watts then that's what I could feed it or because of other dynamics at play it changes power handling?

What would be the resulting power handling of using one coil of a 1000 watt 4 ohm DVC?

I'm in a debate with what seems to be common sense and what's actual. 

P.S. No fret. I'd get wizy with me too with an attitude like I have. I tend to be like Adam Savage.

I reject your reality and substitute my own.





Posted By: Steven Kephart
Date Posted: April 12, 2007 at 8:33 PM
sparky3489 wrote:

Just for clarity...

If the the power handling is halved if only one coil is used since each coil is 500 watts then that's what I could feed it or because of other dynamics at play it changes power handling?

What would be the resulting power handling of using one coil of a 1000 watt 4 ohm DVC?


Power handling isn't halved.  I posted this on page 3, but here's a quote by Dan Wiggins explaining how much power handling is cut:

"Lastly, power handling isn't compromised by a factor of 2; it's usually decreased 10-25%. The reason is that rarely are you current-limited by the gauge of the wire, and voice coils are wound concentrically so you still have the entire thermal mass working for you. Just that now all the power is dissipated in a single voice coil (typically two of four layers) so you may end up with an inert, non-conducting thermal mass insulating one side of the voice coil. This does not halve power handling, but can reduce it somewhat."

Dave mentioned he likes to be a little more conservative with that number, which never hurts.  But the above should be fairly accurate.  I believe subs are usually current limited by the glues used to hold the coils together.  When I worked at Adire heading up the warranty department, we normally saw unwound coils when current limits were exceeded.  What a lovely smell those UPS deliveries were. posted_image

sparky3489 wrote:

I'm in a debate with what seems to be common sense and what's actual. 

You would be surprised at how much is counter-intuitive in this field.  A perfect example is the whole transient response and moving mass argument ("a 15 can't be as punchy as a 10").





Posted By: sparky3489
Date Posted: April 12, 2007 at 11:55 PM

Steven Kephart wrote:

I believe subs are usually current limited by the glues used to hold the coils together.

Ok, now I've heard everything. How in the world can glue limit current flow? This would be saying the glue is acting as a resitance to the coil. Is the glue conductive? wth?





Posted By: Steven Kephart
Date Posted: April 13, 2007 at 2:38 AM
I was using the same wording Dan used above in the quote to prevent confusion.  What I meant was that the weak thermal (heat created by the current) link in a subwoofer is the glues used.  I didn't think I needed to spell it out.




Posted By: sparky3489
Date Posted: April 13, 2007 at 10:26 AM

I question simply because I have a hard time accepting new information that goes against gut instinct.

I'm an absolutist trapped in a non-absolute world. This is MY weakest link. Please forgive.

So what would be the percentage in a quad voice coil if only one coil was used?

I'm guessing 20%-50%





Posted By: haemphyst
Date Posted: April 14, 2007 at 1:31 PM
I'd stick to around 50%, if I had to make a guess at it!

-------------
It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: midnightdenizen
Date Posted: June 02, 2007 at 7:29 PM

I disagree with the notion that it is ok to wire a DVC sub with only 1 coil hooked up. Vance Dickason explains this clearly in his book entitled "The Loudspeaker Design Cookbook". The problem here is that BOTH voice coils are wound around the same voice coil former. One of the T/S parameters refers to the actual weight of the voice coil itself............. Therefore, if you wire only one coil.........that coil has to support the "dead" weight of the 2nd coil and alters the parameters of the speaker as well as putting additional strain on the coil that is hooked up due to the extra weight of the 2nd coil. posted_image



-------------
Billy Smith




Posted By: Steven Kephart
Date Posted: June 03, 2007 at 2:38 AM
Did you read the comments in this thread?  We already discussed the fact that the parameters would change.  Read the entire thread then you will see.




Posted By: haemphyst
Date Posted: June 04, 2007 at 11:27 AM
midnightdenizen wrote:

I disagree with the notion that it is ok to wire a DVC sub with only 1 coil hooked up. Vance Dickason explains this clearly in his book entitled "The Loudspeaker Design Cookbook". The problem here is that BOTH voice coils are wound around the same voice coil former. One of the T/S parameters refers to the actual weight of the voice coil itself............. Therefore, if you wire only one coil.........that coil has to support the "dead" weight of the 2nd coil and alters the parameters of the speaker as well as putting additional strain on the coil that is hooked up due to the extra weight of the 2nd coil. posted_image

Disagree all you'd like, but putting ALL of your faith in a book that is FIRST AND FOREMOST aimed at the amateur loudspeaker designer (a fledgeling in the industry, as it were) that book (I have a copy myself, actually. EVERY major version, somewhere in my house, truth be known...) is not, and also says so within it's pages, never was meant to be, an exhaustive reference. It's really a slightly deeper than skin-deep overview. And while TLDC is a very good reference, useful for MANY aspects of loudspeaker SYSTEM designs, involving enclosures, crossovers, driver selection, etc., it is nowhere NEAR the end-all, be-all of loudspeaker DRIVER building and implementation. Good try, though.   posted_image

-------------
It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: jonspurs
Date Posted: August 02, 2007 at 1:48 PM
Hi,
Thanks for all the info. But am slightly confused. Would appreciate if somone could help me.

I have Pioneer ICE:
DEH-5900MP Head Unit - https://www.pioneer.co.uk/uk/products/25/121/61/DEH-P5900MP/index.html

GM-5300T Amplifier - https://www.pioneer.co.uk/uk/products/25/29/182/GM-5300T/index.html

TS-W2501D4 10 Inch Subwoofer - https://www.pioneer.co.uk/uk/products/25/130/201/TS-W2501D4/index.html

I'd like to know which would be the best way to connect the sub and amp please. What would be better:
1. Wiring the DVC in series for an 8Ohm load that is bridged on the amp? Or will this result in lost power?

or

2. Wiring each voice coil to each channel, so left amp output would go to voice coil 1 and then the right amp output to the second voice coil? Would this create a 2Ohm load for each channel? Would this be 190WRMS each, so 380WRMS going to the sub? Is this what they call parallel?

Thanks For Your Time,
Jon




Posted By: midnightdenizen
Date Posted: August 03, 2007 at 4:23 AM
You seem to be in a bit of a spot on this one. The amp does not match the rated power of the subwoofer. Either of the methods you mentioned above will return about the same amount of power. The only difference between the two would be: both coils in series (8 ohms) bridged to the amp = mono ouput, or wiring each coil to a channel of the amplifier that would result in a stereo output. It would likely be easier for you to wire the sub and series and brige it to the amp, so that is what I would recommend for you in this case. If you want the sub to respond according to manufacturers specs, do not wire only a single coil bridged. You can consult the manu recommendations, and you will not find any wiring schemes that include this type of setup. ( Despite what some of the geniuses in this thread have said above.) If they had intended for the sub to play with only 1 coil, I'm sure they would have included this information in their specs....................Good Luck !

-------------
Billy Smith




Posted By: jonspurs
Date Posted: August 03, 2007 at 4:54 AM
Thanks mate :-)
Yea the amp ain't as powerful, was just given this equipment.
The Pioneer instructions say the same too - do not wire only one VC.
Sorry I'm new to all this, will the power still be 1 x 380W RMS at 8ohms? It's just that I came across another webpage saying something about the higher the ohms, the less power is outputted?

Cheers,
Jon




Posted By: haemphyst
Date Posted: August 09, 2007 at 11:29 PM
midnightdenizen wrote:

( Despite what some of the geniuses in this thread have said above.) If they had intended for the sub to play with only 1 coil, I'm sure they would have included this information in their specs....................Good Luck !


And you need a reality check, my friend. That kind of talk won't make you any friends around here, and in a VERY big hurry. It just so happens that there are MANY people here with FAR more information available to them that you would believe. None of us ever said we were geniuses (but I can assure you, that SOME of us truly are), but we do know to what we refer, and from where we speak, and none of us are likely to spew BS. My suggestion would be to read some of our bios... I'm 40 years old, and I have quite POSSIBLY had more stereo systems (between car and home) than you are years old!

jonspurs wrote:

The Pioneer instructions say the same too - do not wire only one VC.

The reason Pioneer doesn't specifically suggest such a situation, is because they don't want to warranty all the woofers that they would inevitably be required to, because so many people are not aware of the T/S parameter differences, (meaning additional R&D for Pioneer for proper enclosure volume suggestions - more cost in the woofer, i.e. lower profit margin) as well as the reduced power handling. They have enough trouble keeping up with the required RMA load as it is... (They aren't fantastic woofers...)

That being said, midnight is correct... either way you wire it will be safe; series VC and bridged, or one coil to each amp channel, and the power output will be the same, as well as the load per channel. Otherwise, it is PERFECTLY SAFE to utilize one voice coil, should you decide you wanted to!

I'll tell you this right now: If you wire one voice coil, and you observe the proper power reduction, and if you blow it, BECAUSE it is only using one voice coil, I will buy you a replacement woofer, AND ship it to you. All I would ask is that you provide me with the blown one first, so I can see that you aren't just yanking my chain. This I will do for you, I am SO confident that I am right in this. Period. Let's see midnightdenizen put his money where his mouth is, eh?

-------------
It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: phonymike
Date Posted: August 11, 2007 at 2:15 PM

I read through the first four or five pages actually learning things, but then the next few pages became a wizing contest so I'm skipping the rest and replying.

say I paid for a 500w rms stereo amp capable of a 4ohm load bridged, and also bought a DVC sub rated at 500w rms with 4 ohm coils (250w rms a piece.) wouldn't it be silly to turn the amp down halfway and only use one VC? would it not be cheaper to buy an amp with half the power, and a single 4 ohm VC sub or DVC sub at 2 ohms a piece?

I say this because a while ago I bought an amp, and a sub off ebay (brand new and it was cheap!) the stereo amp would do 4 ohm bridged, so I ordered this guy's 10" DVC 2 ohm sub. a week later I get the stuff, and it turns out the sub he sent was the same model number and everything, but the DVC 4 ohm version. I was wized but I wanted to install this doodie. I debated for about two minutes and said love it, ripped it open, and wired it up, 8ohms at first. I was unhappy, 8ohms was totally safe, but not nearly enough boom. so I wired each channel up to its own coil, each channel was capable of 2 ohms, but gave 4 to the DVCs at a quarter the power rating. it was better, but still not it. so I said love it again and wired up 1 VC bridged (300w rms to a 150w rms coil and I knew it.) it sounded great, for about six months, but I knew the day was coming. eventually, the part of the speaker that blew was actually the rubber surround, the coils are still good haha!

at least I'm pretty sure that's how the story goes, it was a while ago. after that I grabbed a 12" from a pawn shop, 4ohm SVC (it's rated a little higher than the amp can output) and haven't had a problem since. I still say if I had the 2ohm DVC sub hooked up it would have sounded better than just 1 of the 4ohm DVC coils. it would have been better for me, the customer, than the shop. I'd be getting what I paid for.





Posted By: l8_9t_thumper
Date Posted: August 28, 2007 at 9:03 AM
Awsome thread!! I read the whole thing and feel prety good about the one vc and shorting out the other.  I just completed my summer time car stereo upgrade by installing kenwood execon 6 by 9's in the back and 7 inch rounds in the doors.  also got a nice kenwood 400 by 4 amp to power the mids. just 40 rms per channel but sounds so much better than just the deck power.  heres where it gets nasty.  I had the exelon kac-521 1000 max 2 channel amp stable at 4 ohms bridged. it was good although stable at 4 ohms it would overheat pushing my two Cerwin Vega V-Max 600 rms DVC subs in a sealed sub zero box.  The upgrade came when I sold the kac-521 and bought the      kac-X1R.  the X1R is the top of the line kenwood excelon amp of 07'.  It clames 1ohm stability, class d, 600 rms at 4, 1200 rms at 2 and over 1000 at 1ohm.  2400 watt max output between 3-25 amp fuses on the face.  it was going to be the perfect match. my vegas are 4ohm per vc and are dvc's.  I naturally wired it at 1 ohm.  it pounds so hard.... it peked at 150.2 db at the local audio source in vancouver, washington.  the vegas take the beating all day long every day.  I have pounded the vegas for two years now.  the problem is at 1 ohm even though the amp clames stability the amp overheats and  cuts off in two minuts of hard core pounding.  dont get me wrong it blows me away but is an imberassment at a signal when it cuts.  I feel if I brought it up from 1 ohm to two ohms it would be more stable and  put out 200 more watts rms.  but after reading the entire thread I worry about the 20 prcent loss in the woofers rms if I run only one of the vc per sub to obtain the two ohms.  I just did my first competition, it was a shame the amp kept blowing the 3-25 amp fuses and wasnt even able to get to the 150db I know it is capable of.  It did 139.6 and took 2nd place in the 0-600 rms at 4ohms class.  they classified you by your amps rateing at 4 ohms not at what you were at because I was a 1 ohm.  so I guess I wonder if there was a resistor I could wire in to add just 1 simple ohm without dissconnecting two of my 4 vc?  Or mabe an old woofers coil or something.I dont have room for any more woofers much less the spare electricity in the charging system to power more woofers.  this is all in my 04' pontiac grand am. Im to the point where I replaced the the  3-25 amp fuses with 3-30 amp fuses and am thinking about doing something drastic to this dissapiontment of an amplifier like takeing it apart and pulling out the dang temprature govener or adding more fans.  to replace the woofers would cost 400 bucks and for that much I could get another kac-X1R.  Im tired of spending money on this system but I demand the best.  I have a 460 big block that need some tlc too.  so at this point I am ready to try anything to raise the ohm load up to two ohms.  I think it would be wiser to potentaly destroy the woofers rather than the brand new amp i got.  Just wanted to let u all know where Im coming from.  I will try the svc and short out the unused vc raise the load to two and push them hard.  I just hope Cerwin Vega rates there watts lower that Kenwood execlon.  I will let u all know how it goes. get back to me if you see a soulution to this small yet large problem

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No Guts No Glory




Posted By: haemphyst
Date Posted: August 29, 2007 at 12:47 PM
I don't want to type it all again... (That, and PLEASE use some punctuation, especially commas and periods, and the occasional new paragraph would be helpful as well...)

Read this thread... Another sticky in the forum. posted_image

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: proatthagame
Date Posted: September 17, 2007 at 5:56 PM

This prolly has a real simple answer but.....

Can someone please tell me how to short one of the coils?

Thanks



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Yours Truly




Posted By: DYohn
Date Posted: September 18, 2007 at 11:42 AM
proatthagame wrote:

This prolly has a real simple answer but.....

Can someone please tell me how to short one of the coils?

Thanks


To short a coil you simply conect a wire from pos to neg.  This will change the Q of the speaker, of course...



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Posted By: proatthagame
Date Posted: September 18, 2007 at 4:44 PM
DYohn] wrote:

QUOTE=proatthagame]

This prolly has a real simple answer but.....

Can someone please tell me how to short one of the coils?

Thanks


To short a coil you simply conect a wire from pos to neg.  This will change the Q of the speaker, of course...

[/QUOTE]

Thanks,  DYohn

Now knowing that....

My amp does 800w bridged. I have two 4 Ohm DVC rated at 400 rms. I want to present a 4 ohm load to my amp. When I hook up one voice coil (shorting the other) on each woofer then bridge the two, I will end up with 8 ohms. According to this diagram (https://www.the12volt.com/getimage/2_4ohm_svc_8ohm.gif)

So if I present the 8 ohm load to my amp bridged then I will end up with 4ohm correct? Assuming I do, then each speaker should get 400 rms. From Steven's remarks about the power handling not really being cut in half but just dropping a small percentage (10 to 25%). Am I going to be overpowering my woofers? Am I able to do this and just make sure my gain is set properly? 



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Yours Truly




Posted By: haemphyst
Date Posted: September 18, 2007 at 11:07 PM
Yes, you'll be rating your woofers for about 300 to 320 watts, so, yes, you will be overpowering them, technically. Proper setting of the gain, and you'll be fine.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: DYohn
Date Posted: September 19, 2007 at 9:24 AM

Why do you want to short the unused VC?  Are you trying to use a non-standard sized enclosure?  Shorting a VC doubled Qms and halves Qes.

If you present an 8-ohm load to your amp you present an 8-ohm load.  What amp and again, what are you attempting to accomplish?



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Posted By: proatthagame
Date Posted: September 19, 2007 at 12:08 PM
DYohn] wrote:

p>Why do you want to short the unused VC?  Are you trying to use a non-standard sized enclosure?  Shorting a VC doubled Qms and halves Qes.

If you present an 8-ohm load to your amp you present an 8-ohm load.  What amp and again, what are you attempting to accomplish?


After reading this....
What about driving just a single coil, and leaving the other open? Well, as you would guess, the push is weaker. The system has a peakier resonance (for the techie types, Qts increases because Qes increases). BUT - let's drive one coil, and short the other. Guess what? Things change from the original (both coils driven) situation, but they also stay the same. The driven voice coil is pushing and pulling, as normal. But what about the shorted voice coil? Well, it's trying to keep things at rest - it's trying to resist ANY motion! The net result is the overall peakiness of the resonance is the same as it was when both coils were driven, even though we are only using half the motor (driving one coil). The other coil helps "tame" the driven coil, so that the system basically behaves the same as before

Kicker kx800.2 - specs - www.realmofexcursion.com/ampguts/Kicker_KX800.2

I was under the impression that when you bridge to the amp, it cuts the impendence in half? Is this correct?
Currently im running to each channel at 2 ohms pushing 400 to each speaker. Its too much for my charging system and myself.
 I want to utilize the option of using 1 vc to save the other one incase the one in use blows then i will have another to work with.
 I have the option of running 200 to each speaker at 4 ohms but i want more then that. So i figured i would do like mentioned above and get almost the same maybe more power at a higher impemdence thus resulting in the amp not having to work as hard as well as having the other coil available when needed.



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Yours Truly




Posted By: DYohn
Date Posted: September 20, 2007 at 8:32 AM

re: "I was under the impression that when you bridge to the amp, it cuts the impedance in half"  No, how you connect to the amplifier has nothing to do with the speaker's impedance.  If it's 8-ohms it's 8-ohms.  Operating a stereo amp bridged into an 8-ohm load generally results in the same power output as the amp's 4-ohm stereo rating.  Your Kicker will produce approximately 400 watts bridged into 8-ohms.

Yes, shorting an unused VC results in the same net calculated Qts as using the coil, but the trade off is that Qms doubles, meaning the speaker has twice the mechanical damping it had before and perhaps more significantly the Qes is cut in alf and Le changes in sometimes unknown ways since most manufacturers do not list single coil ratings.  All of this means you may need to test the speaker to determine the new T/S parameters as the standard enclosure size will not be optimum and you need to calculate a different size using the changed parameters.  Also be sure to de-rate the power handling by about 25%.



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Posted By: smoothdesignz
Date Posted: September 23, 2007 at 9:57 AM
I just wanted to pop in and say THANKS!!! for bringing up a huge topic of debate for a lot of people. Unfortunately, I am the one in the position of having to run a single VC or series down to 8 ohms. For those of you that ask "why would you buy it like that?", I didn't, I actually got most of my equipment for free because I did work for someone or traded the free stuff for other things, so I ended up with an Alpine Type-R D4 10" and an Alpine V12 MRT-757 (a two channel for those that don't want to look it up). I did have it running at 2 ohms bridged, but it clipped severely, so, last night I disconnected the second VC and ran it at 4 ohms bridged instead. I will say this in defense, I am planning on getting a second Type-R D4 as soon as the money's right, since we have one at work.

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95 Mazda 626
Pioneer DEH-P960MP
DEI Stilleto
Boston Acoustic SL60 Front
Boston Acoustic S85 Rear
Alpine V12 MRV-F407
Alpine V12 MRV-T757
2 Rockford Fosgate P2D412
Python 990 Alarm/RemStart




Posted By: extacy
Date Posted: September 28, 2007 at 5:22 PM

So when you wire up a single VC on a DVC sub ... whats the better option ... short the other voice coil (... done by simple attaching a wire b/w + and - right ?) ... or leave the unused voice coil open ?

What would be the approximate changes for box sizes in both situations ?





Posted By: DYohn
Date Posted: October 02, 2007 at 12:17 AM
HERE's a nice summary of how to calculate the changes for different wiring configurations.  I believe this information is accurate.

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Posted By: extacy
Date Posted: October 02, 2007 at 4:21 AM
Thanks again DYohn :)




Posted By: donpisto
Date Posted: November 16, 2007 at 6:06 PM

First off to say I'm no installer but I do have a sufficient amount of knowledge in car audio.

Though running power to a sub on a single coil (of a DVC driver) is not recommended, it can be done. Whether it's damaging or not, well it is and it isn't. If you are not clipping the amp, and it is sending a clean signal and not sending the driver more power than its mechanical and physical limits it will be fine, though i really don't recommend it. However, running one coil is using only half the sub's capabilities, thus hooking up the second coil will lead to being twice the power. Twice the power theoretically is a 3 dB increase. Also, please see the personal expereince portion of this post as it has extended information.

If you were to wire a sub using both voice coils, you can do so in parallel so your impedence will be 2 ohms or in series, with an impedence of 8 ohms.

Here is some personal experience with this issue:

I was running my dual 2 ohm driver in my vehicle, wired in parallel (1 ohm load) and had no problems at all.  I decided to sell the driver and before I did, I had to hook it up in series (4 ohms) and the driver would not play. Tested the coils and one read 2 ohms, the other read 0. NOT A BLOWN COIL, but a DEAD coil. It wasn't burned because the sub played fine, it moved freely, didn't make any scratching sounds, no distortion, and played just fine off 1 coil. Did I have problems with it? Yes and no. It did work fine, however, it also changed the t/s parameters of the driver with only 1 coil working. This change actually changed alot.  Because of it, I sent the driver too much power.  But since only 1 coil was working, the driver received too much power, thus causing a linear offset and denting the cone slightly and it was only half the cone. Had the coil been working and if i pushed it beyond its limits, there would have been a nice circle from the back plate tapping, but as mentioned it was only a half circle.

Simply said, you can run a DVC driver off one coil, but it is not recommended since it changes the thiel/small parameters and can cause damage to the driver once physical and/or mechanical limits are exceeded.





Posted By: donpisto
Date Posted: November 16, 2007 at 6:15 PM
I'd also like to add that running a driver at 8 ohms isn't bad. Yes you will get less power, but think of it this way, your amplifier is also running more efficiently and staying cooler.  Impedence rise will be less significant.  There is a thread on the www.diymobileaudio.com forum that explains this. If someone knows the link please post. I will try and find it as I am having trouble finding it.




Posted By: sunnydaze
Date Posted: December 02, 2007 at 12:06 AM
If the Qms of a speaker is doubled, and the Qes is cut in half, then by definition of Qts, Qts remains unchanged.

If the Qts remains unchanged, then so should the sensitivity of the loudspeaker.

In terms of Le, does anyone know at what frequencies inductance really becomes a factor?

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"Only two things are infinite. The universe and human stupidity, and I'm not so sure about the former."

~Einstein




Posted By: rene123
Date Posted: December 18, 2007 at 9:41 AM

JL Audio's website has a great section explaining the problems with wiring one voice coil.  It can be found under their "tutorials" section and then you click on "Dual Voice Coils".  It basically says that technically it can be done, but you better know why you are doing it and the effects it will have on power and SQ.  Check it out!



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Rene




Posted By: seeker1
Date Posted: March 29, 2008 at 12:36 PM

I was reading the forum topic "running one 4 ohm vc on a dvc sub" wich is now closed, so I could not post any questions. So i'll ask them here and maybe someone can answer them for me. One of the replies mentioned running a varible resistor to adjust Q's on the second coil of a DVC sub.

   ""I have actually used the second voice coil for a system "tuning" device. By adding a fixed or adjustable resistor, you can actually adjust the elctrical Q of the woofer, (ala this article, posted by Steven Kephart of Adire Audio) which will affect the toal Q of the system. Nice. Thanks, Steven! ""

When I tried the link it's dead, does not exist any more, gone.

Does anybody know how to do this. I sounds interesting and I'd like to try it. I'm running a JL 6w10 on a Infinity REF 611 in 96 Mustang. Sometimes it's abit much.

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Only the strong survive.
Eat the weak.





Posted By: sedate
Date Posted: March 29, 2008 at 12:54 PM

seeker wrote:

Sometimes it's abit much.

You mean its too loud?  Turn the gain down a notch.

The w6 is a real flat woofer to begin with. . .



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"I'm finished!" - Daniel Plainview




Posted By: seeker1
Date Posted: March 29, 2008 at 1:18 PM
What do mean by "FLAT"

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Only the strong survive.
Eat the weak.




Posted By: sedate
Date Posted: March 29, 2008 at 2:01 PM

"Q" refers to the overall slope of the bandpass being amplified - so by doing that resistor thing to his woofer Kephart or Wiggins or wherever that quote came from impacted the response curve of the woofer.  The goal of doing this is to make the 'Q' as flat as possible while maintaining respectable output.

I'm assuming (i'm not going to take the time to read the paper, which you can find on web-archive.com, for this quick response)  that whoever was doing that was demonstrating a neat way to edit out a peak in an otherwise peaky woofer system.

This isn't really relevant for you because the 10w6 is an extreamly 'flat' response curve - meaning it isn't peaky at all when left to itself - you'd have to introduce eq'ing or design a box to induce a peak in the response of that particular woofer.

Anyway - I'm making some assumptions about your system, so you should be a bit more descriptive as far as what you like and don't like about your system, include more information about your system, like box size and type, amplifiers used, and such - and I (and the rest of us) could be lots more help.

Anyway, I think the last thing anyone other than an extreme "power user" should be trying to tune a system using resistors between vc's. 



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"I'm finished!" - Daniel Plainview




Posted By: seeker1
Date Posted: March 29, 2008 at 2:39 PM

I'm running an Infinity 611a class d with the following spec's

611a

• 456W RMS x 1 channel at 4 ohms and ²1% THD + N

• Signal-to-noise ratio: 70dBA (reference 1W into 4 ohms)

• 657W RMS x 1 channel at 2 ohms, 14.4V supply and

²1% THD + N

• Dynamic power: 761W at 2 ohms

• Effective damping factor: 6.336 at 4 ohms

• Frequency response: 17Hz – 302Hz (–3dB)

• Maximum input signal: 6V

• Maximum sensitivity: 75mV

• Output regulation: .179dB at 4 ohms

This amp has a 2 channel or a single channel bridged output. I've set up so each coil is powered by individual channels, keeping a 4 ohm load. If I wire it in a single channel setup coils in parallel the load goes to 2 ohm and the output rms is to high and will blow the coils. Being a newbie to this and a virgin to boot, I could be wrong in this setup. I hope not. My confidence would be crushed. But if I am please advise.

The ported enclosure I built following the spec's from JL web page " https://mobile.jlaudio.com/pdfs/8-12W6_BDS.pdf "

A 1 cubic ft ported enclosure.



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Only the strong survive.
Eat the weak.




Posted By: drbizerk
Date Posted: July 22, 2009 at 12:23 PM
i have a 12" ALPINE TYPE X that actually sounds better and beats harder when ran off of only one of its coils. my amp is two ohm stable so the sub wired parallel ( dual 4 ohm ) shows two ohm load at the amp. when cut in half ( using 1 of the 2 coils) it shows 4 ohms and cuts the max output of my amp in half. i dont understand why it is so much louder

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Posted By: spanyerd
Date Posted: August 18, 2009 at 3:56 AM

haemphyst wrote:

1lowgalant wrote:

I know I've seen subs suffer damage due to running only one voice coil on a dvc.

No, you have not. Not SPECIFICALLY from only running one voice coil. What was probably the CAUSE of the damage, if there was truly damage done, was from overpowering the single voice coil......... Nice thing about blowing one coil? You have a second one to go through BEFORE you have to buy another woofer! posted_image

When wiring only one VC of a DVC sub, can you (or anyone really) ball-park how often the "damage" has been isolated to only the one wired VC? Are the VC's typically one of the weaker or stronger links in the chain? I ask because I'm curious as to how much consideration should be given to the likelihood of "having a second one [VC] to go through BEFORE you have to buy another woofer". Coin-toss? Miracle? 1-in-10? 1-in-1000?

Anything would help. Thanks in advance.

Excellent forum!!



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Got a burnin' for some learnin'.




Posted By: pubwoofer
Date Posted: January 04, 2010 at 6:18 AM
i am using a dvc sub and a 4 channel amp, have tried 8ohms in series briged at the amp,its ok but can i wire each vc with its on wire, one set to the + and - of channel 3 and the other set to the + and - of channel 4?, will the amp be then pushing out 2 ohms? my amp says not to bridge with 2 ohm set up..




Posted By: i am an idiot
Date Posted: January 04, 2010 at 7:44 AM
You can connect it with one coil to channel 3 and the other coil to channel 4.  Each channel will see 4 ohms.  It will make the same EXACT power into the 8 ohm bridged configuration you had it at, versus the 4 ohm stereo load.  You should have purchased a dual 2 ohm or a dual 8 ohm driver.  Or get another amp for your highs, and bridge one coil to channels 1 and 2 and the other coil to channels 3 and 4 of your 4 channel amp.




Posted By: pubwoofer
Date Posted: January 04, 2010 at 1:04 PM

[quote]You should have purchased a dual 2 ohm or a dual 8 ohm driver[quote/]

thx for that, another monday night quarterback LOL.





Posted By: atmospherejo
Date Posted: March 03, 2010 at 12:44 AM

hi guys ,

i read all your posts and i think its very fruitfull and i loved the way everybody chatts with an open mind to learn and this is exactly why i just became a member .

I NEED HELP WITH DVC SUBBS

I HAVE AN AMP WHICH IS SAID IT DRIVE 200 WATTS AT 4 OHM AND 300 AT 2 OHM OK

THE POINT IS I HAVE JBL SUB P1224 WHICH IS A DVC 4OHM EACH 200 WATTS EACH , WHAT I KNOW THAT IF I GO TO 8 OHMS THE HANDLING IS 400 WATT , IF I WENT TO 2 OHM WILL IT STILL BE 400 WATTS OR IS IT GOING TO BE 200 WATTS , WILL IT BE RISKY TO GIVE IT A 300 WATTS TOO?

REGARDS

PLEASE EXPLAIN THE ANSWER IF U CAN.



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ATMOSPHERE PERFORMANCE
CAR AUDIO & VIDEO




Posted By: 1lowgalant
Date Posted: March 04, 2010 at 1:56 AM
WOW!! doesn't seem like it's been almost four years since i posted this thread. how time flies! nice to know a lot of people have benefited from it. great info guys!

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Whatever you do, DO NOT let the white smoke leak out of the wires.....




Posted By: afdanw
Date Posted: October 07, 2010 at 5:00 PM
i am going to throw myself under the bus here and make myself look like an amature.  Before reading this, i would have taken your side of this argument 1lowgalant.  I remember asking this question when i first started installing years ago, and i got the answer that,"both must be wired or it will cause damage."  The installer who gave me that answer even wen as far as to explain why.  "He siad each coil powered half the sub, one did the right side of the sub, and the other did the left.  If you were to power only one side; obviously, the sub would move out of ballance and end up damageing itself."  I took that answer as truth and never questioned it.  8 years later and i read this thread and start to think about it.  Now, thinking about that answer i was giving so many years ago, it was obvuiosly a dumb answer i was given, and cannot believe that i took it as truth.  Thanks for the info, and for bumping a 5 year old post so that it would be read by people newer to the site, like myself. 

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If your cousin is such a good installer, and he will install anything for a 6 pack; why are you talking to me?




Posted By: joshr
Date Posted: June 09, 2011 at 4:40 PM
The whole point of the dvc sub is so you can use both coils to run more power and to run more subs. If you only use one vc then you r wasting your money. Any svc sub will smash on a dvc sub only running one coil. If you are going to run one vc on a dvc then you might as well buy a svc sub


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jr




Posted By: basshead77
Date Posted: October 28, 2012 at 1:00 PM

Hello All....I have a Question for all you Pros out there. Can I wire my JL Audio W710 3ohm SVC 750W rms sub with my Memphis Audio C3-12in 4ohm DVC 600W rms sub??? They are each in there own seperate enclosures(2 boxes) I want to hook them to my Kenwood KW-910D Mono Block Amp. Rated at 500W rms @ 4ohm or 900W rms @ 2ohm. Are they compatable together? How should I wire them? Thanks a ton!posted_image



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basshead77




Posted By: glh1
Date Posted: October 31, 2012 at 11:56 AM
That amp isn't really powerful enough for either sub to be powered properly and you will probably end up sending a clipped signal to them with it, not to mention have phasing issues and freqeuncy cancellation.

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GLH




Posted By: i am an idiot
Date Posted: October 31, 2012 at 12:32 PM
The only SAFE way to wire those drivers on that amp is to wire the coils of the dvc driver in series, then parallel the 2 drivers at the amp.




Posted By: 1lowgalant
Date Posted: February 11, 2013 at 2:17 PM
WOW!! almost 7 years later and my topic is still an important piece of information!! i'll have to say, this topic showed me that no matter how much you think you know, you're never too old to learn something new. it's the people like stevdart, DYohn, Steven Kephart, and especially haemphyst that make this site such a valuable tool to anyone. if not for them, i may never have understood the technical aspects of the subject in question. Dan Wiggins' papers are a must read!! huge thanks to you guys and everyone else that makes this site what it is!! posted_image

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Whatever you do, DO NOT let the white smoke leak out of the wires.....




Posted By: warped82
Date Posted: February 17, 2013 at 11:07 PM
Hello. I have read this entire post from top, to bottom. It seems to have a lot of good information, yet I'm still confused on the best configuration for my amp and subs.

Amp has a

Maximum Power Output 2 x 1000W
Bridgeable RMS Power @ 4 Ohms: 1x2000W

2 Ohm Stable

I have a single 15 inch sub with Dual 4 ohm Impedance 3600 Watt Peak Power.

After reading this forum, I'm even more confused than when I started on how to wire it to get the most power.   I intended on wiring both voice coils in parallel, giving the sub a 2 OHM load to the amp. I don't think this is a good idea now. Would It be best to bridge the amp and wire the subs for an 8 OHM load ? Or should I just wire a single voice coil to get the full 2000 watts out of the amp? Or How about a channel to each coil? I have read every way mentioned, I was just curious as to what you suggest as the safest most efficient way to wire this combination thanks.




Posted By: drbizerk
Date Posted: February 18, 2013 at 1:16 AM
wire your sub @ 8 ohms and bridging it at the amp will bring it to 4 ohms




Posted By: warped82
Date Posted: February 18, 2013 at 4:45 PM
drbizerk wrote:

wire your sub @ 8 ohms and bridging it at the amp will bring it to 4 ohms


I'm a noob when it comes to hooking things up right. I had several DIY systems in my teens. They all actually sounded pretty good, never mind the fact that I payed little or no attention at all to the OHMs, if I recall all the subs I owned previously were single voice coil, and probably 8 ohms.   I am a little confused as to what you are saying. Are you saying bridging the amp and wiring the subs at 8 ohms will carry a 4 ohm load to the subs?   I was under the impression that if I wired the subs at 8 ohms the amp would carry an 8 ohm load and I would lose some power, which is why I would assume any one would even suggest only using one voice coil, to match the amps 4 ohm load when it is bridged at maximum power. This would allow the amp to push all 2000 watts of its max power. My speaker is rated to handle 3600 watts. Would you be getting the most power out of your amp using only one voice coil ?   From what I have read if the speakers are wired at 8 OHM this decreases the amps peak power handling.( 2000 watts @ 4 OHM ) any way to figure out the wattage at 8 ohm ?) Is there that much of a difference ?    Sorry for all the questions, its just that I have seen a lot of difference in opinion in this thread, and i'm just trying to get the most out of my amp and speaker.




Posted By: drbizerk
Date Posted: February 19, 2013 at 1:09 PM

any time you BRIDGE an amp your ohm load at your speaker wires will be divided in half. Hope this helps





Posted By: haemphyst
Date Posted: February 24, 2013 at 11:57 AM
drbizerk wrote:

any time you BRIDGE an amp your ohm load at your speaker wires will be divided in half. Hope this helps



This is why the phrase "ohm load" is SO incorrect!!! The number of ohms is halved, true, but when the number of ohms is halved, that's TWICE THE LOAD, not half!! It can't be both. It's ohms or load, but not "ohm load". Ohms is impedance. Impedance is the load. "Ohm load" is like SQL... it doesn't exist.

What you SHOULD say is this:
any time you BRIDGE an amp your ohms at your speaker wires will be divided in half, which is effectively a doubling of the load. Hope this helps

Even though TECHNICALLY this isn't really correct, either... While the ohms presented by the loudspeaker connected to the terminals never changes, the load the amplifier channels experience is doubled, due to the power supply rails being connected across the load for twice the voltage... Twice the voltage will generate twice the current, thus, four times the power. The "twice the current" caveat here is what makes the amplifier think it is connected to a lower impedance than it actually is.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: haemphyst
Date Posted: February 24, 2013 at 12:07 PM
Warped:

You will always have 8 ohms. The impedance of the woofers are not carried. It only tells you what the electrical resistance of that driver is. That number is also *always* whatever the impedance of the woofer is. Impedance is a dynamic number, stated as ohms, with the nominal impedance of a given driver the stated number - i.e. 8-ohms, or 4-ohms. The amplifier creates power, it doesn't "handle" power. Drivers "handle" power. The amount of power an amplifier can create is determined by the load attached to the terminals. If an amplifier is stated at 1000W at 4-ohms, then you can generally safely say that at 8-ohms it will make about half that amount, possibly a little more.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: haemphyst
Date Posted: February 24, 2013 at 1:08 PM
Warped:

I just read your first post/question.

No, you cannot parallel the voice coils, as that would be 2 ohms, and then a bridge to the amplifier would put a 1-ohm load on the amplifier - incompatible.

Your best bet would be to put one voice coil on each channel (IF IT IS ACTUALLY A TWO CHANNEL AMPLIFIER) and run it that way - at 4-ohms per channel. That, by the way, is EXACTLY the same load and power combination as wiring the voice cols in series for an 8-ohm load, and then bridging the amplifier. Your amplifier will "see" 4-ohms per channel.

WHAT amplifier, EXACTLY do you have? Nearly all mono- amplifiers have two sets of terminals (four terminal screws) but the outputs are internally paralleled. If this is the case with yours, then you can still use the amplifier, and wire one coil to each terminal set, and you'll be presenting your amplifier with a 2-ohm load. We need to know first what your hardware is, though...

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: drbizerk
Date Posted: February 25, 2013 at 1:21 AM

i have a JBL/CROWN A6000GTI amplifier. Please school me. When nothing you said applies to that amp I have about 10 more that you will like.  Thank you for the TECHNICAL term lesson....I will admit that i was slacking or maybe just trying to help someone by answering a question to the best of my ability in a way that they may understand. Did you ever get around to giving the "correct" answers?





Posted By: haemphyst
Date Posted: February 25, 2013 at 1:58 PM
drbizerk wrote:

i have a JBL/CROWN A6000GTI amplifier. Please school me. When nothing you said applies to that amp I have about 10 more that you will like.  Thank you for the TECHNICAL term lesson....I will admit that i was slacking or maybe just trying to help someone by answering a question to the best of my ability in a way that they may understand. Did you ever get around to giving the "correct" answers?



I have no idea what you are asking/saying... I would also ask how my answers are "incorrect". I was ALSO just trying to help you, I wasn't doing anything beyond that.

As to the amplifier you mentioned... It's a mono amplifier, the output screws are connected internally, and if you put a 4-ohm woofer on each set of screws, (+- and +-) the amplifier will be loaded to 2-ohms. It's already bridged internally. It's not bridgeable further. If you connect across the outside terminals, you are not bridging it at all, as the negative terminal pair and positive terminal pair are electrically connected inside the amplifier.

Now... if you'll read my posts, I asked the OTHER poster what HIS amplifier was...

Next.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: warped82
Date Posted: March 02, 2013 at 3:59 AM
haemphyst wrote:

Warped:

You will always have 8 ohms. The impedance of the woofers are not carried. It only tells you what the electrical resistance of that driver is. That number is also *always* whatever the impedance of the woofer is. Impedance is a dynamic number, stated as ohms, with the nominal impedance of a given driver the stated number - i.e. 8-ohms, or 4-ohms. The amplifier creates power, it doesn't "handle" power. Drivers "handle" power. The amount of power an amplifier can create is determined by the load attached to the terminals. If an amplifier is stated at 1000W at 4-ohms, then you can generally safely say that at 8-ohms it will make about half that amount, possibly a little more.


Okay, well that makes sense. My terms might not be technically correct, but i'm pretty sure you can follow what i'm saying. I do appreciate you correcting me and explaining it in detail though.

I know that the amp determines the power it creates based on the ohms presented to it by the driver.   Which is why I posted my original question. My amp produces the most power when it is bridged and connected to a driver that has an impedance of 4 ohm. Yes I know that this is divided in half, and that each channel individually will have to carry a load of 2 ohm, with a total impedance of 4 ohm. This is why I don't want to wire the sub at 2 ohm, because my amp is only 2 ohm stable.
I made the assumption that this is why people suggest only using one voice coil. With an amp like mine, would I not get the most power out of the amp by using only one voice coil ? ( 4 ohm )   From reading this entire thread, in previous post it was stated that this will lower the maximum power the driver can handle. Since my amp only puts out a maximum of 2000 watts bridge @ 4 ohms.(I think this is exaggerated some by the manufacturer), but its what it said on the box. The speaker according to the manufacturer can handle 3600 watts. I might be wrong on this but the more power sent to the driver the louder it is, at least this is my assumption. Even if the amps peak power handling is lowered, it just seems logical that the speaker would still be louder at this configuration. I could wire the speaker to present 8 ohm to the amplifier, but as you said this would lower the wattage that the amp puts out. I know that wiring the driver at 8 ohms is probably the safest thing to do, but it's economy equipment anyways. When the speaker finally arrives I will wire it at 8 ohms, then compare it to a single voice coil at 4 ohms. I will share the results. Thanks for all the helpful information.




Posted By: warped82
Date Posted: March 02, 2013 at 4:05 PM
Its an economy brand. Pyle https://www.pyleaudio.com/sku/pla2378
It is two channel. There are 4 terminals and it has a switch to function in both mono and stereo modes.

Its a low budget amp, but I have been satisfied with it. Do you know anything about this model ?




Posted By: warped82
Date Posted: March 03, 2013 at 12:05 AM
warped82 wrote:

Even if the amps peak power handling is lowered, it just seems logical that the speaker would still be louder at this configuration.


Sorry I meant the speakers peak power handling is lowered.




Posted By: DYohn
Date Posted: April 03, 2013 at 11:22 AM
warped82 wrote:

Its an economy brand. Pyle https://www.pyleaudio.com/sku/pla2378
It is two channel. There are 4 terminals and it has a switch to function in both mono and stereo modes.

Its a low budget amp, but I have been satisfied with it. Do you know anything about this model ?


What do you want to know?

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Support the12volt.com




Posted By: 281clo
Date Posted: November 04, 2013 at 2:35 PM

extacy wrote:

So when you wire up a single VC on a DVC sub ... whats the better option ... short the other voice coil (... done by simple attaching a wire b/w + and - right ?) ... or leave the unused voice coil open ?




I'm sorry to ask a question that extacy already asked, but the reply was via link and the link is dead.

So just to clarify, I WILL be wiring only one VC on two subs, should I short the unused coil or just leave it open? Thank you in advance.

Great thread by the way, top in searches and still helping many people after years of being started.

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Let your bass push you thoughts outside the box.





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