Under power! need advise

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=18352
Printed Date: June 12, 2024 at 12:52 AM

Topic: Under power! need advise

Posted By: skyRyder
Subject: Under power! need advise
Date Posted: September 01, 2003 at 6:36 PM

hello again guys!!

i have a 15" alpine DVC 500w rms @ 2ohm.... so it mean 250w RMS per coil..... at the moment i still looking for to buy another amp, so my amp ALPINE MRV T757 (2 ch, 200w per ch @ 2ohm) ... i dont want to bridge, it the same sub (bridge 4ohm at 500wRMS) amp bridge at 4ohm 400W-rms..

If i connect each Voice Coil to each channel, it only 50w under power to the sub...

is that give any harm or will damage my sub? or i should wait for new amp? or it is okay for just normal use... i talk to ALPINE dealer, he said should be ok...

thank in advance guys

Replies:

Posted By: nedgeworth
Date Posted: September 01, 2003 at 7:49 PM

Well i would think it would be fine. The only thing that would concern me is having a left and right channel going to the sub. So if you've got a stereo imput i would think you might damage the sub but i'm not too sure. But power wise it is fine. Hopefully someone else can shed some more light on this for you.

Posted By: italnpimp59
Date Posted: September 01, 2003 at 8:32 PM

nah, having a stereo input is fine. i see all the time huge powerful subs DVC run in stereo to a big amp. it will be fine... the 50w under power shouldnt be a problem either.

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Posted By: skyRyder
Date Posted: September 01, 2003 at 9:30 PM

is it better for me to run one voice coil to each Channel (amp)?...... or better bridge it?...

coz the alpine install has informed me that, when i run it each coil to each channel (amp),... it give me all the option and much better sound (maybe he talking about the mono block amp?) but i do mention about my amp, he said it shouldnt be a problem..... coz he try to get me buying his MD500 (about the same amount power as mind at themoment)......

Posted By: Ketel22
Date Posted: September 01, 2003 at 10:08 PM

to bridge the amp is better on the sub, if you put one channel to each vc then you run the chance of blowing one of the vc. i ran a channel to each of my vc and it blew one of the vc because of inconsistancies in the channels.

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Quad L Handyman services

Posted By: skyRyder
Date Posted: September 01, 2003 at 10:15 PM

hmm......

anyone else has experienced this type of situation or know the solution of this time of problem?

advises will be appreciated!!

Posted By: Ketel22
Date Posted: September 01, 2003 at 10:22 PM

didnt like the advise about hitting it?>

haha just thought id put in my experience with them

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Quad L Handyman services

Posted By: skyRyder
Date Posted: September 01, 2003 at 10:57 PM

hmm true!!... someone has said that it should be fine, but just affraid it will give steroe at some stage (un-stable),,,, so bridge it!!!

Posted By: nedgeworth
Date Posted: September 01, 2003 at 11:03 PM

Would be safer having the same signal to both coil's that way.

Posted By: wvsquirrel
Date Posted: September 02, 2003 at 3:42 AM

Independant wireing is NOT A GOOD IDEA. Here's some info from JL Audio on the dangers of Independant Wiring. It is possible to do, but I stongly recommend trying to find an amp capable of properly running both voice coils from the same channel.

If the sub is a 2ohm DVC (both voice coils are 2ohm), then you can bridge the amp and wire the subs in series for a 4ohm load. This is safer than wiring each voice coil to a different channel/amp. Let me know if you want a diagram and I'll e-mail you one...

What is the model number of the sub?

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Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.com

Posted By: nedgeworth
Date Posted: September 02, 2003 at 3:48 PM

From what i can remember from his previous posts it is the 2ohm dvc model. SWR-1521D. Pretty sure.

Posted By: skyRyder
Date Posted: September 02, 2003 at 6:40 PM

that's right nedgeworth.... it 2ohms DVC

wvsquirrel, what is the advantage of the parallel hookup (connection) https://www.jlaudio.com/tutorials/dvc/dvcAdvantage.html .... if i have 2ohm DVC and my amp is 2ohms x 200RMS (2ch), or bridge 400RMS x 1 @ 4ohms ... so when i hookup the DVC up in parallel is it 4ohms? or 2ohms load?

Posted By: nedgeworth
Date Posted: September 02, 2003 at 6:44 PM

If you hook your sub up in parallel you will end up with a 1ohm load. Which your amp can't deal with so you have to wire it in series for a 4ohm load so your amp can cope.

Posted By: wvsquirrel
Date Posted: September 03, 2003 at 3:49 AM

The advantages of Parallel wiring is that is halves the ohm load of the sub. (1) 2ohm DVC wired in parallel will produce a 1ohm total load.

The general rule of thumb is: Less Ohms = Less Resistance = More Power

Most amps are able to produce more power at a lower ohm load due to decreased resistance. As is the case with your existing amp as well. But since you have a multi-channel amp, then you have to look at it on several different levels.

Level 1 - 2 Channels (Stereo)
Your amp will produce more power per channel at 2ohms per channel then at 4ohms per channel. Your amp's minimum stable Stereo ohm load is 2ohms per channel.

Level 2 - 1 Channel (Mono)
You have an amp that is capible of Bridging, which effectively combines the output of 2 channels into 1 channel (hence the term Mono, or one). When you bridge an amp it is essentialy like wiring 2 SVC subs or 1 DVC sub in series (even though you only use the + from one channel and the - from the other channel). What I'm getting at is you essentially double the minimum Stereo ohm load per channel to get the minimum Mono ohm load (and yes, there are exceptions but your amp is not one of them). A 2ohm Stereo stable amp is usually only 4ohm Mono stable (the ohm load gets doubled for the bridge). I'm sure there is someone out there that can explain the math behind it better then I can, but that is the basic logic behind it. A 1ohm Stereo stable amp is usually 2ohm Mono stable, a 2ohm Stereo amp is usually 4ohm Mono stable, a 4ohm Stereo amp is usually 8ohm Mono stable, etc...

That's why I said earlier (as did Nedgeworth), you need to wire your 2ohm DVC in Series for a 4ohm bridge. Your amp is not stable at a Mono/Bridged ohm load lower then that. You run a major risk of frying the amp and/or sub if you were to try a 1ohm bridge (ie. if you wired in Parallel). You also run a major risk of frying that sub if you were to wire each voice coil to a seperate channel on the amp. You're gonna get the same wattage output running the 4ohm Mono bridge as you would wiring each voice coil independantly at 2ohms. In fact, you may actually get a little more. So save yourself the trouble and agrivation and do it right the first time, before you have to spend more money on replacement equipment! Save that money for New Upgraded equipment instead posted_image

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Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.com

Posted By: skyRyder
Date Posted: September 04, 2003 at 1:21 AM

hmm thank guys...

any suggestions on good amp that will give 500w @ 2ohms x 2 or.... bridge 4ohm x 500w.....

i need a good deep bass sound... brand and model number plz

thank

Posted By: wvsquirrel
Date Posted: September 04, 2003 at 1:30 AM

Actually, you want to look for either:

500 x 1 @ 1ohm
500 x 1 @ 4ohms
500 x 1 @ 4ohms Mono/Bridged

I'll get back to you on some suggestions...

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Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.com

Posted By: skyRyder
Date Posted: September 04, 2003 at 1:41 AM

thank mate.

i actually see this MRV 1505 (second hand) for sale $550 AUD.... pretty good price..however i really like the 1507...

again i still want someone to suggest me some good gear and know wat is good!!

thank

Posted By: wvsquirrel
Date Posted: September 04, 2003 at 1:45 AM

Ok, here's some suggestions for an amp to run (1) Alpine SWR-1521D (2ohm DVC 500RMS 1500Peak)

JBL BP600.1
600 x 1 @ 1ohm
It's a reliable amp, although they may be a little difficult to find. Unfortunately you would really have no room for expansion later on down the line if you decided to add another sub(s). But it would more than suite you purpose right now.

Audiobahn A18001DT (Class D Mono amp)
600 x 1 @ 4ohms
1200 x 1 @ 2ohms
1800 x 1 @ 1ohm
You would have more than enough power right now, plus you would have an amp that you could add subs to later on and still have plenty of power to play with. Audiobahn makes excellent amps, and this one would deffinately be worth looking into.

Audiobahn A1500HCT (High Current Mono amp)
500 x 1 @ 4ohms
1000 x 1 @ 2ohms
2000 x 1 @ 1ohm
Again, you would have enough power for right now, plus you would have an amp that you could add subs to later on and still have plenty of power to play with. I'm not a big fan of High Current amplifiers for subs, but this one would still work

Out of those 3 amps, the JBL would be the cheapest priced (around $200 U.S.). The others you can figure on close to around $1,000 U.S.

There are still many more amps out there, so don't just take my advice! Look for an amp with the minimum specs that I gave in the post above and you will be bump'n in no time

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Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.com

Posted By: wvsquirrel
Date Posted: September 04, 2003 at 2:06 AM

I'm having problems finding specs on the MRV-1505 and MRV-1507. I believe they are part of the V12 series, but I'm not sure.

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Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.com

Posted By: wvsquirrel
Date Posted: September 04, 2003 at 5:24 AM

Here's the diagram I was telling you about. Sorry it took so long (I use Rockford Fosgate's Wiring Wizard for the basic portions, then manipulate the rest manually)

posted_image

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Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.com

Posted By: wvsquirrel
Date Posted: September 04, 2003 at 5:29 AM

Forgot part of the first diagram, and I couldn't edit/delete my last post for some reason. Oh well, here it is again...

posted_image

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Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.com

Posted By: nedgeworth
Date Posted: September 04, 2003 at 3:23 PM

These might be some help to you. I knew my searching skills would come in handy one day. MRV-1505 and MRV1507

Posted By: skyRyder
Date Posted: September 04, 2003 at 5:52 PM

wvsquirrel and nedgeworth thank alot mate,... that very helpfull thank so much for the info and help....

very helpfull

Posted By: nedgeworth
Date Posted: September 04, 2003 at 6:06 PM

No problem. posted_image

Posted By: skyRyder
Date Posted: September 04, 2003 at 7:28 PM

what do u think of Cadence Z4000 Amplifier

https://www.cadencesound.com <= official site.... someone want to sell it to me only 450$ ...retail about 690 to 750

not a bad price but i need to know the reputation of the amp? is it worth of buying? ... or it just good for it own price!!?

Posted By: nedgeworth
Date Posted: September 04, 2003 at 7:32 PM

It's a nice amp but i think you will be best to get a mono block amp. Will power that sub nicely but i hope your electrical system would be up for the job with that amp as the cadence class A/B amps suck a bit of juice. There mono blocks are very nice i own a Z1000.

Posted By: nedgeworth
Date Posted: September 04, 2003 at 8:23 PM

Looks like you might be best off to get yourself a 2 channel amp and run it bridged in series for that sub. (refer to wvsquirrel's 2-channel amp bridged configuration @ 4ohms)

Suggested amps

Kicker KX500.2

RMS Power
In Watts, All Channels Driven
@ 13.8V, 4??Mono, 0.4% THD 500

Dynamic Power
In Watts, All Channels Driven
@ 14.4V, 4??Mono 570

Coustic 601se

Rated Power @ 14.4 V (0.2 % THD)

4 Ohm Mono
1 x 600 Watts

Cadence z8000

4 Ohm Mono
1 x 500 Watts

Posted By: IceCold
Date Posted: September 05, 2003 at 7:35 PM

You cannot bridge DVC subs period, wait for an amp!!!!! Plus, running channels to each coil will overheat the amp

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Ice Cold Racing, you'll be frozen at the line....