Printer Friendly Forum Posts - what would you choose?

So I am guessing I will be getting a very similar answer about a power acoustik amplifier? Just had to ask. I also have been offered an ultimate amplifier 600 rms 1200 peak brand new for 250$ CAD but I dont really trust the guy, it is from a flea market (first reason why) and all the stats he told me about amplifier I went home and looked up and were false, plus he told me to wire my subwoofer in a series to have a 1 ohm load to the amp, now correct me if im wrong but dual 4 ohm voice coils wired in a series present a 8 ohm load correct? Is ultimate a better company to trust over mtx? is it worth the extra 100$?

Ultimate is also flea market crap. You are looking in the flea market range of products, you are going to get flea market crap. Boss, Ultimate, Power Acrapstick etc. Come up with a budget and we can find you a real amp.

Dual 4 ohm coils wired in series = 8 ohms. Dual 4 wired in parallel = 2 ohms.

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Top Secret, I can tell you but then my wife will kill me.

I will not ever be able to afford these 1$ per watt amps. Is there a company that is "on top" of the flea market world? One that there claim of wattage is close to real output? I have heard impressive thing from ultimate and people who buy ultimate...but the difference is I have never heard the high end of the audio world but I have heard high middle class stuff and I feel it compares. Im still shopping and refuse to rush into any purchase before researching and proving the best deal, and will always seeks other opinions before buying.

Hah I found the best deal possible for 200$ I am getting an alpine v power m-1000. This is a reliable better amplifier correct?

New or used? CDN or US?

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Top Secret, I can tell you but then my wife will kill me.

used with scratches on top but works 100% and its 200$ CDN

Yes,that was an attempt at humor...Never had a customer call boss ...bose...?

aznboi3644 wrote:

tommy... wrote:

NO BOSS...Unless you pronounse it BOSE...Then go ahead...

If you pronounce it Bose...get your head out of your ***...Bose is overrated overhyped crap.

Boss sucks.

FYI, that subwoofer will not survive being fed a real 1000 watts RMS.

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M.E.C.P & First-Class
Go slow and drink lots of water...Procrastinators' Unite...Tomorrow!

MTX would be the solid choice. Not a big sq amp for speakers but plenty of good power for your Audiobahn 1505 sub.

Isn't the 1505 or the 05 series dual 2ohm subs? And yes it will take the power no problem as long as you set your amp right. I ran 1000rms to my Alum15 off a JL 1000/1 all day with no porblem. Any idot can blow any sub with a 300watt amplifier. A good installer will never make that mistake.

Audiobahn has some great subs. They also had some not so great stuff when they expanded their product line to include making everything like radios and indash monitors and a line of 30 different sub series. Similar to what MTX is doing now with 20 different lines of amps and subs.

I didn't think their subs were crap. I've installed most of them at one time or another and on a variety of different amps with great success. Usually only making small mods to the box or amp setup.

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Just do something

soundcontrol wrote:

Isn't the 1505 or the 05 series dual 2ohm subs?

Hey you know what your right! The guy I bought it from said it was a dual 4 ohm sub, and I guess I just skipped over the ohms when I was looking at it for my self (dumb). Thanks so much for pointing that out.

Out of all the amps you've mentioned I would take a used alpine over the rest anyday. I have owned several alpine amps over the years and they have all been great. One look on ebay will give you evidence to my claim. There are lots of 10+ year old alpine V12 series amps on there that are still 100% functional. Boss, Ultimate, MTX, not so much. Also you can bet that the ratings on that alpine are pretty close to accurate for the given voltage those other brands are almost certianly overrated. The first amp I ever owned was an old solid black alpine and never had an issue with it.

So finding out that my sub is dual 2 ohm voice coils has really screwed my calculations up. Should I run it at 1 ohm or 4 ohms? The amp is 1000w @ 2 ohm and 600w @ 4 ohm but there is no mention of 1 ohm. Im not sure whether to wire it for 1 ohm or 4?

if they dont give you a 1 ohm rating then i wouldn't feel safe running it at 1 ohm. i would series it for a 4 ohm load to get the 600 watts.

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There is absolutely no way to run a 2 ohm dvc on a mono amp at 2 ohms?

you can just run one coil of the sub woofer, but it will decrease the rms rating of your sub by 20% (i think) and you would probably blow that sub by running 1000W to 1 coil

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Not with wiring both voice coils. you'd either get one ohm (parallel) or 4 ohms (series). just wire it for four ohms and hook it up to your amp. the db drop from 2 ohms to 4 ohms is not really too noticeable for the human ear....If you're not competing you should be good!

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...half of the truth can be worse than a lie. <----Roger Russell said that..

If you have a meter you may want to double check the sub wired in parallel and in series and see what it actually meters out at.

The reason is, most subs will be rated at dual 4 or dual 2ohm subs and when you read the RE: for the sub it shows to be really close to its actual ratingbut not exact.

For example JL audio 13w6v2 dual 4ohm from the JL website

Its dual 4ohms but when you read the specs

RE: 6.50 Ohms *** with an additional note.......

Re (DC resistance) is measured with the voice coils in series, for parallel-wired specification divide Re by 4. All other specifications remain the same.

So this dual 4ohm sub in series is 6.5 ohms and not 8ohms and in parallel is 6.5/4= 1.625ohms and not 2ohms. Very very close but not exact.

Try putting a meter on your sub in parallel first and see what happens. If it is closer to 2ohms then say 1 or 1.5 ohms you may be able to run it parallel.

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Just do something

soundcontrol wrote:

If you have a meter you may want to double check the sub wired in parallel and in series and see what it actually meters out at.

The reason is, most subs will be rated at dual 4 or dual 2ohm subs and when you read the RE: for the sub it shows to be really close to its actual ratingbut not exact.

For example JL audio 13w6v2 dual 4ohm from the JL website

Its dual 4ohms but when you read the specs

RE: 6.50 Ohms *** with an additional note.......

Re (DC resistance) is measured with the voice coils in series, for parallel-wired specification divide Re by 4. All other specifications remain the same.

So this dual 4ohm sub in series is 6.5 ohms and not 8ohms and in parallel is 6.5/4= 1.625ohms and not 2ohms. Very very close but not exact.

Try putting a meter on your sub in parallel first and see what happens. If it is closer to 2ohms then say 1 or 1.5 ohms you may be able to run it parallel.

it doesn't matter that much because the resistance changes anyway once the sub is moving to music. the ohm ratings are a base line and like you already know are not exact.

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soundnsecurity wrote:

soundcontrol wrote:

If you have a meter you may want to double check the sub wired in parallel and in series and see what it actually meters out at.

The reason is, most subs will be rated at dual 4 or dual 2ohm subs and when you read the RE: for the sub it shows to be really close to its actual ratingbut not exact.

For example JL audio 13w6v2 dual 4ohm from the JL website

Its dual 4ohms but when you read the specs

RE: 6.50 Ohms *** with an additional note.......

Re (DC resistance) is measured with the voice coils in series, for parallel-wired specification divide Re by 4. All other specifications remain the same.

So this dual 4ohm sub in series is 6.5 ohms and not 8ohms and in parallel is 6.5/4= 1.625ohms and not 2ohms. Very very close but not exact.

Try putting a meter on your sub in parallel first and see what happens. If it is closer to 2ohms then say 1 or 1.5 ohms you may be able to run it parallel.

it doesn't matter that much because the resistance changes anyway once the sub is moving to music. the ohm ratings are a base line and like you already know are not exact.

So are you saying it is safe to run parallel or in a series?

no, it isn't safe to just do one or the other without considering the amp's limits. there is a big difference in resistance between series and parallel . what i WAS saying is that you should go by what is written on the spec sheet because that is the base line. a speaker will never be exactly what the manufacturer rating says, the resistance changes all of the time when the sub is in motion. a 4 ohm sub will peak and dip while it is in motion. amps are made handle these short peaks but constantly running an amp with a lower resistance load on it than it is made to handle constantly with lead to the destruction of your amp or sub (in this case your sub will probably go first)

in short, dont run your sub on your amp at 1 ohm. use single coil 2 ohm or series both coils into 4 ohms. that is what will be safe for your specific setup. i dont have enough faith in your sub to take 1000 watts from your amp regardless if the amp can handle a 1 ohm load which you cant be sure of either. go with what is safest

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So if I'm not mistaken someone said I will barely notice the difference between running it at 2 ohm or 4 ohm. I am finding this very hard to grasp as it is only 600rms and 4 ohm and 1000 rms at 2 ohm. Am i wrong here?

they mean you wont HEAR a difference. when it comes to subs and all things being the same, if you double the power going to a sub, you should gain about 3 decibels. a 3 DB change, plus or minus, isn't really audible to the human ear in the bass frequency range.

so the power difference between 600w and 1000w is a little less than double so you wouldn't notice an audible difference which is why you should run it at 4 ohms because its the safest for your sub and amp. your AMP will take a 2 ohm load but i dont think your sub can take 1000w to just 1 coil. also like i said, using just one coil will drop the rms of your sub by a little bit because its only one coil which makes it more likely that you will blow your sub.

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The MTX 5601 is rated at 300@ 4 and 600@ 2

I would guess maybe a 1000max at 2ohms. I would either consider a different amp to maximize your sub amp setup or series at 4ohms and get 300 to maybe 500watts max.

Do not ever just run one voice coil. It's bad for many reasons and not recommended by the manufactures for a reason.

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Just do something

soundcontrol wrote:

Do not ever just run one voice coil. It's bad for many reasons and not recommended by the manufactures for a reason.

What are your reasons for it being bad? Whatever they are, you're wrong... We took 15 pages over here to COMPLETELY debunk the single VC option... There is ABSOLUTELY nothing that MANDATES the use of both voice coils.

The link in that article to the PDF on the now defunct Adire website should be linked to this item, here in the member's downloads section...

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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."

soundcontrol wrote:

The MTX 5601 is rated at 300@ 4 and 600@ 2

I would guess maybe a 1000max at 2ohms. I would either consider a different amp to maximize your sub amp setup or series at 4ohms and get 300 to maybe 500watts max.

Do not ever just run one voice coil. It's bad for many reasons and not recommended by the manufactures for a reason.

I am no longer considering the mtx amplifier. I have purchased the alpine v power m1000 which is 600rms @ 4 ohm and 1000 rms @ 2ohm. I am just waiting for the amp to be shipped to me.

JL Audio is my choice

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01 Lexus GS430 SOLD.. 04 BMW 545i Sport, NAV Logic7

Because when people use one coil it is to get maximum power out of an amp like in this case which in return will blow the sub.

If you have a dvc sub that takes 1000watts total(500 per coil) but your amp will only do the wanted 1000watts at an ohm you can only get by wiring one coil your end result will be a blown voice coil. The sub will play and sound good im sure all the way up to the point you get that burnt smell.

Your other debunked topic only shows that a lot of people use one coil and haven't damaged a sub yet. You could start another topic on how running power wire from your battery through a door jam is a great idea and have plenty of people say yeah they have done it with no problem but that doesn't make it a good idea or debunked. If it was intended to be ran off one coil they/manufacture would be the first to tell you that and how great their product is compared to everyone elses. But the fact that none of them do probably has a reason behind it.

In this situation running one coil would not end well.

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Just do something

You're wrong. Straight up... And you OBVIOUSLY didn't read the entire thread.

A 1000 watt, DVC woofer is NOT 500 watts per coil - it is 1000 watts of total energy dissipable by the motor structure. When only running one voice coil on a woofer you derate the total capacity of the woofer by about 20%, (not 50%, as you incorrectly believe) so a 1000 watt woofer will still be perfectly safe at 800 watts, all running through one voice coil. It's a little thing called thermal mass.

Now, he has a 2 ohm DVC woofer, meaning he has two 2-ohm loads. If he were to only use one of those loads, it will be safe at 800 watts input power. Being as it is a 2 ohm load, his amp will make 600 watts into one of the voice coils. You do the math: 600 watts of power being put through an 800 watt sink... That's a 33% buffer. PLENTY of safety margin.

He'll be perfectly safe doing that. Read the entire thread, and learn a little something. There is VERY sound, concrete proof in there, PROVING that it is perfectly safe to run one coil, as long as the MARGINALLY REDUCED power handling is accounted for, and "in this situation", *I* have already accounted for the reduced power handling.

To skateit_12, run the one coil, get all the power you think you will be missing.

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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."

I was wrong about the one voice coil and plesently surprised.

Why wouldn't companies mention that to their customers is crazy. I sent emails to several companies and will post their replies in a few.

It still wouldn't be ideal in his situation because the amp is going to produce about 1000watts. I think it would be cutting it kinda close. If you take into consideration the chance of being borderline on power and not properly setting gains it could led to a short lived voice coil. I would still use cation and consider another amp in the longrun.

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Just do something

Replies from companies on using one voice coil:

Kenwood

Question Body: I have a KFC-XW1224D dual 4ohm sub and was wondering if the sub is 600watts rms for both coils would it be safe to run 480watts (or 80% of the total RMS)to just one voice coil and not connect the other voice coil? If no, could you explain why? If yes, could you explain why?

Answer: No, you cannot. You always want to stay within a 15% range for optimal performance and less change of damaging either the speaker or amp. Example: If the amp is 100watts RMS, you can use a speaker with an RMS of 115watts. If you’re running 480watts to just one coil, 300watts RMS, you’ll end up damaging the coil.

JBL same question

Answer: Good evening and thank you for your inquiry. The total RMS handling for the sub is 400 watts RMS for both voice coils. Although it is rated at 400 watts RMS, it can handle a bit more power. You would be find with running up to 650 watts RMS to the whole P1224 sub.

question: Ok, so you are say using one voice coil is a bad idea, even with less then reccomended RMS power?

Answer: It would not be recommended.

JL Audio same question

Answer: We always suggest driving both voice coils of a woofer, it won’t cause any difference in performance but, the woofer will be operating the way it was designed to.

Digital Designs Audio same question

BEST ANSWER EVER:

< color=navy size=2 face=Arial>When you put current through turns of wire, a magnetic field is created, this alternating magnetic field is working against the permanent magnetic field generated by the magnets. The strength of the alternating field is determined by the input voltage and the length of the wire. The more wire you have, the more field created.

< color=navy size=2 face=Arial>< color=navy size=2 face=Arial>If you only use 1 coil, the field generated will be less than with both coils, but you won’t hurt anything. 70% power is probably a safer level to play, but clean power is always less an issue than clipped power to the sub

Still waiting to hear from RF

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Just do something

soundnsecurity wrote:

they mean you wont HEAR a difference. when it comes to subs and all things being the same, if you double the power going to a sub, you should gain about 3 decibels. a 3 DB change, plus or minus, isn't really audible to the human ear in the bass frequency range.

so the power difference between 600w and 1000w is a little less than double so you wouldn't notice an audible difference which is why you should run it at 4 ohms because its the safest for your sub and amp. your AMP will take a 2 ohm load but i dont think your sub can take 1000w to just 1 coil. also like i said, using just one coil will drop the rms of your sub by a little bit because its only one coil which makes it more likely that you will blow your sub.

does no one read anything i write?

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Charles is a driver engineer at Harmon, and I have used his information before. I spoke with him at GREAT lengths about this again tonight, (we've had the discussion before)and we plugged different numbers in... Here's where we ended up:

"I don't know that I'd recommend it, but I can't say there's anything wrong with it." - Charles Sprinkle, Harmon International.

This was one of his closing comments in our conversation, and reasons for this statement follow:

Mathematically, the power dissipation capabilites of the motor structure do not change, however, the mechanical parts (the adhesives, specifically) can still only take just as much heat in close proximity, whether through one voice coil or two. Additionally, the power capacity of a single voice coil will be 1.414 times the "theoretical power capacity" of a single voice coil. In the case of our 1000 watt woofer in this particular thread, "500 watts per voice coil", times 1.414 = 707 watts. A de-rate of just short of 30%. This is the current limitation of the windings, generally.

If you run the coils in series, you will end up with the same output, even at 300 watts, as running one voice coil at 600 watts. The reason for this is the fact that you will be running 600 watts through half the number of amp-turns within the magnetic field, reducing your output by 3dB, which is EXACTLY the same output as running 300 watts through twice the wire within the magnetic field. There is ZERO difference!

While the amplifier runs cooler, with lower distortion, you end up with 1: better efficiency (this means less heat), 2: 3dB of additional headroom, 3: half the distortion, and 4: twice the damping factor. Additionally, you are using ALL the copper (in the voice coil) that you paid for, AND there is simply ZERO chance that you will ever blow your woofer due to clipping! Clip it off, baby, you'll still be perfectly safe! Charles was unable to say that except for running in an RDO (Resistively Damped Operation) as described in the PDF to which I linked, there would be no reason to only run one coil, especially seeing as your outputs will be identical, so, I stand corrected.

So, in conclusion, use both coils, wired in series, and be perfectly happy with your setup.

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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."

Well d#mn it so now just to make sure in dumb mans english.

A dvc sub with 600 watts of total power to one voice coil is the same output as 300 watts total power (series or parallel for example) to both?

Because both coils would be working more efficently (in dumb terms) then the one coil by its self to move the sub?

If that is the case then wow!!!

Awesome knowledge has been dropped like a ton of bricks. I need a Dew and some advil. posted_image

That should be added to the other post as well.

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Just do something

In parallel, you will have the same number of turns in the gap, BUT twice the current, oweing to the lower impedance, so you will end up with a 3dB gain over the other scenarios.

Your dual voice coil driven output is ONLY the same as a single voice coil when wired in SERIES!

Dew and Advil... sounds like a cooktail made in heaven!

And, to soundnsecurity, I did read what you read. I just neglected to mention it, and my apologies for the oversight. You are completely correct in your thread, BUT, you are more correct than you know, now that I have added in my additional information! Take it to the bank!

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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."

Ok, well that is awesome to know. D#mn awesome!

Dew goes with anything.

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Just do something

haemphyst wrote:

In parallel, you will have the same number of turns in the gap, BUT twice the current, oweing to the lower impedance, so you will end up with a 3dB gain over the other scenarios.

Your dual voice coil driven output is ONLY the same as a single voice coil when wired in SERIES!

Dew and Advil... sounds like a cooktail made in heaven!

And, to soundnsecurity, I did read what you read. I just neglected to mention it, and my apologies for the oversight. You are completely correct in your thread, BUT, you are more correct than you know, now that I have added in my additional information! Take it to the bank!

that post wasn't really directed AT you. but indeed now i know a little bit more about why i was right. truthfully i was just doing some basic sub to amp matching the way i was tought to do.

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