Noob question re:DVC subs and impedance...

[Rochambeau 10+ year member]

Hi all and thanks in advance...

I am an audiophile in training and am shopping for an SQ system for an '06 Mustang. Mostly I listen to rock & jazz.

It was suggested to me today that I should consider a sub system with a 4-channel into four 8" subs. At first I was doing the calculations in 4-ohms and wondering if I had enough power per sub to make them happy. Then I read at Crutchfield (not shopping... learning) that using DVC subs I can run the subs at 2-ohms and get twice the power and, as Crutchfield put it, "A DVC sub offers the same performance whether it's wired in series or parallel. Its power handling levels, frequency response, and other specifications do not change — the only difference is the impedance presented to the amplifier." Can the same be said for the amp? If yes, well that sounds like a free lunch and we all know there is no such thing.

So I guess my question is: If I do run them at 2-ohms, what suffers, if anything?

While on the subject... Anyone have suggestions for 8" DVC subs to maximize SQ with that amp? I can afford up to $250.00 per sub.

Specs on the amp:

Arc Audio 4200SE 111x4 @4 ohms, 205x4 @2 ohms.

Click to read more...

 

[95stroked1500 10+ year member]

there are other electrical changes that happen. but there's much more research for you to do and learn before you get into all that.

have you just simply considered getting a more intended sq sub for your application? like a pair of 8 ohm 10's or 12's to mono bridge down to 4 ohm for safe max rms power.

there are some physics involved in the diff between a 12 and an 8. but the idea that an 8 is better for sq than a 12 is a total misconception. it all depends on how the sub was engineered and your install.

 

[Duke 10+ year member]

RE, Tang Band, SoundSplinter and Ascendant Audio make some awesome 8s. The Crystal CMP 8 is an awesome sub from what I've heard. The Tang Bands and AAs are 4 ohms though with 150 rated rms handling. That amp would probably work good on 4 of those. Don't rule out alot of the DIY brands like Dayton and other Parts Express type brands.

Edit: TC Sounds makes an 8 that looks pretty promising on paper. TC 1000 8. RMS is around 400. FS of 25 hz, and 24 Xmax. Copper shorting ring FTW!!! Would be awesome in less than a cubic foot. I'm thinking about getting one to mess around with.

 

[CBFryman2 5,000+ posts]

I'd stay away from 8's SQ system or not. Look more into a single 12.

As for DVC, All it means is it has two coils wound on top of one another. It allows for more wiring options. Yes, it does mean that if your amp produces most power at 2ohm buying a DVC Dual 4ohm sub will allow for twice the power output when compared to a nSVC Single 4ohm sub. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

But two times the power is only 3dB in theory and at times less and at times more.

 

[Duke 10+ year member]

DVC creates alot more BL doesn't it?

 

[Rochambeau 10+ year member]

I'd stay away from 8's SQ system or not. Look more into a single 12.
As for DVC... it does mean that if your amp produces most power at 2ohm buying a DVC Dual 4ohm sub will allow for twice the power output when compared to a nSVC Single 4ohm sub. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

But two times the power is only 3dB in theory and at times less and at times more.

Yes, I am hesitant a bit on 8's too.

Again forgive my n00bness, but in the absence of a real trade off (ie: higher noise or distortion) why not squeeze out the extra dbs.

Also, aren't speakers happiest when given power significantly closer to their max RMS capability?

Finally, won't four 8s give me louder bass (when I want it) than a single 12?

I hope that doesn't read snottyish, I really am that ignorant. ;-)

 

[Duke 10+ year member]

I had to cram around 2 times their rms power in them to make my subs happy.

 

[95stroked1500 10+ year member]

DVC creates alot more BL doesn't it?

series the coils sens drops and bl increases. parallel coils sens increases bl drops. but for a single 8 ohm coil vs 2 4 ohm coils in series, they would be the same. but for that example you compare the same speaker. so it has the same motor assembly, same coil dia, same vc wire gage, same length, etc..

 

[squeak9798 5,000+ posts]

Again forgive my n00bness, but in the absence of a real trade off (ie: higher noise or distortion) why not squeeze out the extra dbs.

Technically the higher the power the higher the distortion. Nothing is free. The further a subwoofer excurts, the less linear everything in the subwoofer becomes.

Now, that doesn't mean that the increase in distortion will make it sound "bad"....only that it will, technically, increase.

Also, aren't speakers happiest when given power significantly closer to their max RMS capability?

Too many variables to state something like that.

Enclosure size, for example, affects mechanical power handling capabilities. So no, more power will not always make the subwoofer "happier"...it's entirely possible to damage a subwoofer with it's rated "RMS" power, depending on the installation enviornment.

Finally, won't four 8s give me louder bass (when I want it) than a single 12?

Possibly, depending on what specific speakers we are comparing and what enclosures they are in.