dual vioce coil sub/amp wiring

hotponyshoes · 04-25-2005, 03:12 PM

i have a duel voice coil sub and my amp is rated at 2x60w or 1x150w. should i wire up a channel to each input or just put 2 lengths of cable to the same bridged channel on the amp and send to both inputs? thanks!

Cris · 04-25-2005, 03:16 PM

You really need more power than 60W to power a sub, to give you enough bass. May I suggest another amp. Perhaps a mono block one.

Atomsmasher · 04-25-2005, 03:57 PM

don't bridge it. Run it RMS, if u take it to the 2 ohm load, you are going to have hot amps and crappy sound.

Once, in my crx, I was running 2 kicker 8's(svc) and 1 orion 15 (DVC) I ran the setup in series parrallel and it kick butt and my amp never really broke a sweat.

WhiteRabbit · 04-25-2005, 07:58 PM

when wiring a subwoofer to your amplifier, its important to make sure the loads achieve the power production/consumtion you wish.

in your case, with a 60x2 150x1 amp, I will assume that that amplifier is rated for 60x2 at 4 ohms? 150x1 at 4 ohms? that load will play a major factor, later.

now, your subwoofer is probbaly a dual 4 ohm subwoofer. This would mean they are 4 ohms per coil. might be 2 ohm DVC, could be 8 ohm DVC, could be something else. But probably dual 4 ohm.

now, you have two wiring options (not three!). You can wire the coils together in series, or you can wire the coils together in parrallel. you can easily find diagrams on the internet to show you how to do each.

now, to calculate loads with pairs of even resistances, its pretty easy. series wiring doubles your load, parrallel wiring halves it. Thus, your only two wiring options with a 4 ohm DVC subwoofer will be 8 ohms (series) or 2 ohms (parrallel). this you can then wire up to your amplifier.

assuming your amplifier follows ohms law (it wont, due to regulated power supplies and other factors I dont understand) hooking up your subwoofer in an 8 ohm load to your amplfier will feed your subwoofer about 75 watts. Rated at 125 rms at 4 ohms, twice the load will result in poweroutput of about half. each coil would get about 40 watts. If we wire it in parrallel, the amp would see a two ohm load, and try to feed the subwoofer about 250 watts. the output transistors of your amp may or may not be able to handle that kind of current flow. If it cant (and I will bet it cant), then your amplifier will overheat and release the magic smoke.

crappy sound doesnt really enter into the picture. you cna have crappy sound with a different amp, with the same amp, wired to 8 ohms, wired to 2 ohms, etc. thatll be a factor of tuning, rather than electrical loading. furthermore, 60 watts is plenty for a subwoofer. its simply not enough bass for Cris. Do you think the ouput of this equipment will be enough for you? wire to 8 ohms and be done. not enough? might want to look into new equipment. subwoofer AND amp.

you DO have a third option, though I dont recommend it. you can wire the amplifier one coil per channel. the subwoofer will see 60 watts per coil, or 120 rms total. The problem with this, is that each coil has the potential to recieve a different signal than the other. If this happens, it will be a contributing factor to crummy sound. You can help protect agasint that by doing something like using a splitter to ensure right and left input are identical, however I prefer not to go that route no matter what.

technically, going by theoretical unregulated amplifier power based on ohms law, wiring 8 ohms going mono will giv eyou the same power as 4 ohms stereo anyways. the theoretical 50 watt amp would be rated for 50x2 @ 4, 100x2 @ 2, 200x1 @ 4, and 100x1 @ 8 ohms. so your subwoofer wired in stereo would see 50 watts a coil, or 100 watts across the whole driver. wred in 8 ohms mono would see 100 watts across the driver, or 50 watts per coil.

Except wired mono would be a guarantee each coil gets the same signal!

for a practical answer to your question, without explanation, I would wire your subwoofer to your amplifier in series for an 8 ohm mono load. the better course of action would be to purchase a new amplifier, one stable at 2 ohms for your subwoofer, or a second subwoofer so you can achieve a 4 ohm load, or a different subwoofer that is a 4 ohm mono subwoofer. The fact is, your equipment is very poorly matched as is (this is assuming I am right assuming your subwoofer is dual 4 and your amp is 4 ohm stable max mono). so the bottom line in this case is run your equipment under its capability, or get new equipment.

hotponyshoes · 04-26-2005, 03:22 AM

Thanks WhiteRabbit, I just knew it had to be more complicated than I thought. The book for my amp says 2x65w at 4ohms, 2x75w at 2ohms or 1 x 150watt at 4ohms. You are right about each coil being 4ohm so I will try wiring them in series to the bridged channel and see if it gives enough kick (the sub is mb quart and rated at 175w rms) if not i will wire in parrallel and if i kill the amp i will replace it with a 2ohms stable mono version me thinks!

shizzle · 04-26-2005, 03:44 AM

I am interested to know the quality and "thump" that the finished system will have. Please post a detailed review of your setup. Thanks in advance, and good luck!

kevinlekiller · 04-26-2005, 08:00 PM

Hi, sorry for posting this in your thread but I dont want to make a new thread for a simillar question.

My amp has 2 channels , bridgeable and 2 ohm stable, I have two 4 ohm (single voice coil subs).
The Subs are 120 watts rms each at 4 ohm and the amp is 240 watts rms at 2 ohm (120rms 4 ohm).

Im running them this way: Channel 1: sub 1, Channel 2 : Sub 2.

Is it possible to bridge them and run them at 2 ohms ? Im guesing running them parrallel Chanel1 + and Channel 2 -.
Is this correct?

WhiteRabbit · 04-26-2005, 08:04 PM

yep. the side of your amp should have a little picture showing which two terminals are the ones for amp output bridged. but otherwise, you got it. just wire both subwoofers together in parrallel, and wire that to the amp bridged. the amp will see 2 ohms mono.

WhiteRabbit · 04-26-2005, 08:07 PM

out of curiosity, what amp is that? 2 ohm stable small amplifiers arent very common, especially low budget ones. itd be nice to know offhand one of them to recommend to others when they accidentally pick poor equipment.

kevinlekiller · 04-26-2005, 08:31 PM

Hi WhiteRabbit : Pyramid PB444X Super Blue

shizzle · 04-27-2005, 12:31 AM

is that link in his sig what I think it is?(kevinkiller?)

kevinlekiller · 04-27-2005, 05:58 PM

I saw in the forum rules not to post thread's about it but I didnt think it was an offense to put it in my signature.

If it is against your rules, please tell me to take it out. And I'm sorry if it offended or will offend anyone.

WhiteRabbit · 04-27-2005, 08:17 PM

no offense taken, we are americans. We save being offended for the anti-american ultra liberals. and the canooks of course >;p

hotponyshoes · 05-21-2005, 05:10 AM

ok, so i have tried it both ways (the sub that is), runnin the amp in mono and wiring in series so with 1x150w@4ohm the 8ohm sub should be getting 75w and also running the amp in 2x65w stereo so the sub should be getting 130w. it gives lots more kick in stereo but i know i need the same input to each channel. now i am taking the stereo out of my soundcard, into the front amp, from the chain out into my rear amp. my q is if i take the chain out of the rear amp, run into a y cable to combine the stereo into mono and into a y cable to feed both channels of the sub amp will i 'short out' the stereo and back-feed mono into the other amps? thanks!