alright this is my question if i get 2 kicker solo-baric l5 subs that are "dual 4 ohm" voice coils and i bridge them how many ohms do i have for a load? i need to know so that i can figure out what amp to get. thanks

 

don't feel bad, some installers have trouble figuring this stuff out.......

use this formula for inducters in parallel: 1/ 1/L1 + 1/L2 + 1/L3.......

L1,2,3...etc.. being the impedence value in ohms

inducters in series: L1 + L2 + L3...........

 

now im really confused

 

Like this

 

Or this

 

in the first drawing it is:


.............1
________________

....1..................1...........=......2ohms
..____.......+.. ____

....4 oms........4 ohms



the second drawing shows the paralled DVCs in series, 2 ohms + 2 ohms = 4 ohms


the inducter formulas may be overkill, you've probably noticed that a parallel connection halfs the impedence while a series connection doubles the impedence.....imagine that!


that's why I think it's funny that some of the professionals have trouble with this.

 

alright thanks. i think i got it know. so if i get a 4 ohm stable bridged amp i shoulb all set with those subs. any ideas on what amp? the subs are 75-600 watts rms each so wouldnt i want like a 1000 watt rms amp? to get the most out of the subs?

 

sorry, my fractions got all squeezed together up there in the first posting.

yes, parallel hookup of two speakers with 4 ohm impedence will place a 2 ohm impedence on the amplifier

series hookup of two 4 ohm speakers will get you 8 ohms.

with your setup you will need a 4 ohm single channel unless you can find a 4 channel that can be bridged to two 2 ohm channels....it would have to be a powerfull amp. A nice JL audio 1000/1 class D amp will treat those nice!

it might not make a difference in the sound, but it will save you some wire if you series the DVCs and then pararllel connect the two drivers together (one speaker wire to each driver instead of two)

 

Odd question; will a setup like this be better then just one 12" sub? More airflow? Or just more work for the same sound?

 

Here's my idea on it. If you have a nice amp you know that from 2 ohm to 1 ohm the power usually doubles (some expections like JBL BP series where 2 ohms same as 1 ohm).

So if you're running a 4 ohm DVC with Voice Coils in Parallel you get 2 ohms. But if you run 2 4 ohm DVCs with Voice Coils in Parallel / Parallel you can squeeze 1 ohm out of it.

Therefore you can double your air flow and double the subs (+ 3 db louder) while powering the same setup off the same amp as you were using before. Since you double the output on your amp you will get the same performance from each sub.

Am I making any sense... I think I lost myself.

 

2 DVC drivers with Voice Coils in Parallel / Parallel
Connecting the voice coils of each driver in parallel (+ to +, - to -) and the drivers themselves in parallel (+ to +, etc.) will result in the following impedances:
Dual-6 Ohm Subwoofers: 1.5 Ohms
Dual-4 Ohm Subwoofers: 1 Ohm
Dual-2 Ohm Subwoofers: 0.5 Ohm

 

If I remember right, JL Audio amps have a self adjusting power supply to match any impedence between 1.5-4 ohms. At least mine did anyways. There are probably others which do this as well. So with 4 ohms to 4 ohms, you are still getting max power to your speakers. Check with the manufactures to be sure of this, I could be wrong.

I wouldn't think it's possible to get a 3 dB gain with a JL amp going from 4 ohms to 2 ohms or 2 ohms to 1 ohm, 3 dB of gain would have your subs pushing 2000 watts from a 1000 watt amplifier! The amp would already be pulling 80 amps to give you 1000 true rms watts, you would need 25.2 volts or 160 amps available for your amp, I would not recomend increasing the voltage although 160 amps available for the stereo system would be just fantastic!

correction: even a class D is less than 100% efficient, you would need slightly more power available than 1000 watts, if you want to get 1000 watts from your amp.

 

No, you make sense, but not for this application.

He wants to rig up two DVC subs so the final resistance is 4 ohms. Then he's going to run his amp at 4 ohms.

That's why I asked if this setup makes any sense. It's not even close to fireturd350's diagram.


If he was showing the amp a lower resistance, like, 2 ohms, I could see a benefit. But overall, to the amp, it's just like having one subwoofer.

That's why all I can guess is that he'll have extra physical subwoofers to move more air with... and wondered if it's worth it- as opposed to one 12" sub.

Know what I'm saying? He's not doubling/quadrupling any power from the amp.

Even Junkyarddog's statement doesn't make sense (not picking on anyone!)
:
A 4 ohm single channel amp? Driving 2 DVC subs, of which, the total impedance is 4 ohms? Might as well just drive 1 SVC sub!

 

Ah- here we go. This is what I'm talking/asking about. What's the difference between these two setups? Apologies to AJ for somewhat-copying his picture

 

the main difference that I can see is the total power will be going through 2 seperate coils in each driver and there will be two drivers to share this power. Instead of one coil and one driver.

since mr. tightwhp already has these subs, there really is no turning back. I do not see the disadvantage myself. Each coil will deliver 1/4 of the power provided and they will do it in unison. I would assume that the four coils pushing two subs will be more likely to perform better than one SVC sub handling all that power.

I would recomend to use a high end class D amp, even if your temted to pick up a cheaper imposter. It will stand up to the abuse for years to come and hold it's value if you want to sell it later.

I had a JL Audio 500/1 monoblock amp which I enjoyed very much. It powered two 4 ohm IMPP subs (2 ohms at the amp) and it sounded exellent! Cheap subs and a nice amp.....this goes to show that the amp is not to be compromised!

JBL makes some high powered amps that are stable at 1 ohm.

this is good because you can run all of your coils in parallel, but the fact remains that a 4 ohm single channel amp will deliver the same power to those subs wired for 4 ohms as a 1 ohm single channel would deliver to the subs at 1 ohm. This is why a JL Audio 1000/1 or another quality class D amp would be perfect.

Yes, single channel 4 ohm amps exist!

this is known in the electronics industry as impedence matching to achieve maximum power transmission.

 

OK, I get it now. I don't see how he will be gaining much since he will be cutting the power to them. Say 500 watt amp at 4 ohms pounding one solo, add another split the watts your only getting 250 for both of them now. We're just running about. Have you bought the amp yet? If so what amp did you get? If not I would consider getting an amp that would let you run 1 ohm on it. Why waste money when you can get more power?

 

I need to make a correction to an earlier statement I made.

An amplifier with a variable power supply or impedence matching circuitry will provide max power to any load within it's range.

some amps with 'fixed' circuitry will power subs, but they work best with the lowest impedence they can handle. hooking up 4 ohm speakers to a 2 ohm capable channel won't cause any damage, doing the opposite will likely destroy the amp if it is not protected.

An amp made to match 4 ohms will still power the subs as much as an amp that can match the subs at 1 ohm.

I would get a 1 ohm capable amp and wire those coils in parallel, that is the simplest solution. A 1200 watt class D would be ideal.

 

You could also take a look at the JBL 1200.1 they put out 1200 watts at both 2 ohms and 1 ohm. That's what I'm planning on pushing my 18s off of.


And there 259 bucks from www.ikesound.com

 

Okay, so, if we figure a "normal" mono amp, in which best performance would occur if it was run at 1 ohm...

Which one of the side-by-side pics that I posted would work the best? Or are they the same... leaving the "one sub" option the best because it's (A) cheaper (B) more simple (C) less to go wrong?

 

Yes, but the whole idea behind DVC subs is wiring flexability. You're not taking advantage of that with it wired that way. DVC are made that way so it is easy to wire and change the ohms. He already has/thinking about getting 2 4 ohm DVC subs. I say it's useless to run them in 4 ohm mode. You're not taking advantage of the amp that way. They could be ran down to 2 ohm each (amp on each) or 1 ohm total (1 amp). You will get more power.


I don't see a point in running it at 4 ohms when he doesn't have an amp and he can just buy a 1 ohm stable amp. And boom more bang for the buck (literally).

Here's another question. I don't really see how that 1st design works. I get the + to + to amp + and the - to - to amp -.... but the inside links - to - bridged to + to + isn't hooked up to anything. If you want to get a 4 ohm you need to do this.

 

hey tomp that drawing you made doesnt sit right with me. how is he going to have full effect of a dvc sub when only one coil per sub is wired up. the way you have it the positive of one sub is hooked up to the amps positive and the negative of the other sub is hooked up to the negative on the amp. how are they going to work? i think you might need to do a little redrawing...unless i am really stupid here.

 

The left half of the drawing is a copy of what AJ posted; two voice coils on each DVC sub.

He parallel'd both DVC coils, on both subs. Then he series'd the subs to show the amp 4 ohms.

And I asked how that was different from one sub showing the amp 4 ohms.

Crap this wasn't the point of my question, to bicker over the damned drawing!

BUT- How does that not work? Your drawing is the same as the original above, but you did it differently. The version I copied had the coils wired in parallel, then the subs in serial. You wired the coils in serial, and the subs in parallel.

So is the consensus that:

1. rigging up two DVC subs of a total impedance of 4 ohms

2. IS EQUAL TO, in sound quality and decibels

3. to one SVC sub with impedance of 4 ohms ???

Because that's what I always thought.

Here. Let me redraw this.

 

see below

 

(laughs) How was that for a re-drawing?

I still don't see the point of wiring up DVC subs like that. So I asked, figuring I didn't know something, and now we're arguing over the damned diagram.

 

That's what I've been saying to begin with... unless you have an amp that puts out max at 4 ohms and you want it to run cooler (maybe) do that... else run the 2 DVC to 1 ohm and push the amp for all it's got.

 

Yes, heated debates seem to crawl out of the woodwork around here from what I have seen LOL.