Is there a noticeable difference in sound quality or clarity when you run a pair of subs at 1ohm instead of 2ohms or 4 ohms?

I haven't noticed any, and I've run the exact same set up...with different amps...at 2 ohm stereo and 1ohm mono. The 2ohm amp was a Hifonics zeus Vii (old school zed audio) which delivered an underated 450 watts rms per channel @ 2 ohms. The 1 ohm amp is my Hifonics brutus bx1205d, rated at 1200 watts rms @ 1ohm and it's class D. They both sound great, clean, tight bass, it was hard to tell which was playing. The difference, price, efficiency, and size. The 4ohm monsters are huge, expensive, and relatively inefficient..meaning you need more juice from your car to get the same amp power to your subs.

__________________
2004 300M SPECIAL
Alpine CDA 9833
Alpine Pxa-h701
Alpine Rux-c701
Rockford fosgate p400-4
Rockford fosgate p4004
Hifonics BX 1205D
JBL c608 GTi
JBL p693
Infinity 2.5" center channel
Alpine type R 12"(2)
all active SQL set up with 1900 watts rms

Yes there is a difference in detail, the higher the impedance, the more accurate deatil you will get. Damping factor of the amplifier is the issue responsible for this. The more damping an amplifier has, the more control it will have over the woofer's motion, as the woofer will induce back EMF to the amplifier, and the amplifier must ignore the back emf from the driver, it does so with higher resistance.

__________________
E.C wuz here

It makes a really big difference if you run the amp at a lower impedance than what it was made to do. So check and see what the amp is stable to. IE if it is made to run best at 2 ohm and you run it a 1 ohm, you will likely notice a big difference in SQ. Not to mention your stressing the amp in ways it wasn't designed to be stressed/used, so it may end up on the service bench faster!

__________________
Tony Dehnke - Salesus Reptilius for some 12v stuff

for amps that are 1ohm stable what is considered a good damping factor?

I have a 1ohm stable amp that lists the damping factor as 1W/50 hz >240....would I notice a difference if I switched to an amp with the same rms output at 2 or 4 ohms?

I second that damping factor is the main factor. Amp specs mostly list DF numbers at 4 ohms. Every time you half the impedance - you half the DF. e.g. DF at 4 ohms is 100, or DF at 2 ohms is 50, or DF at 1 ohm is 25 on the same amp. As long as you have DF of 25 and above, you should not be able to physically hear a difference. A lot of users prefer to have a DF of 100 at a final load, but thats just overkill, but hey I myself like overkill. I run an Arc amp at 1 ohm, and this amp is rated at >1000 DF. So, at 1 ohm it would have to be at >250. So go ahead, and run your subs at 1 ohm, but make sure the amp is at least DF 25 at this point.

__________________
Direction > SQL
-----------------------------
Alpine 9887
Steg K2.03 > 1.2" CDT ES-010, 7.1" CDT ES-07, CDT 560i
Arc Audio KS1000.1 > 2 x 12" Arc Audio D4's(Arc Series)
Rockford Fosgate Riot Cables
Monster Cable 300 Series Speaker Wire
Focal Plain-Chants
Dynamat
Monster Cable 2-Farad Cap
Optima Yellow Top
120 amp alt

"It sounds so good - it hurts my face" - Sasha

Steg > good price at www.number1sound.com
CDT > good price through Ross on CCA

just a note regarding the Hifonic's damping factor. It's rated at 250, unfortunately it doesn't specify if that's at 4ohm. Assuming it is, that's still about 62.5 at 1ohm...which is inaudible by most accounts. I found it very difficult to find any brand name amp with less than 50 DF at it's final load rating. That's why many companies don't even list the spec., it's irrelevant these days as long as the amp is used as intended.

__________________
2004 300M SPECIAL
Alpine CDA 9833
Alpine Pxa-h701
Alpine Rux-c701
Rockford fosgate p400-4
Rockford fosgate p4004
Hifonics BX 1205D
JBL c608 GTi
JBL p693
Infinity 2.5" center channel
Alpine type R 12"(2)
all active SQL set up with 1900 watts rms

As a side note: Damping Factor is NOT Logarithmic *spelling?*
So if you half the impedance, Damping factor will be less than half of what is was at full impedance.

__________________
E.C wuz here

I have a pair of Polk Momo MM2124DVC subwoofers in a sealed box. The nominal impedance of each Sub is 4 ohm and max power handling of each sub is 400watts RMS.

I bought a Nakamichi PA1500 mono amp(RMS: 500 X 1@4 ohm or 1200 X 1@1ohm) which is 1 ohm stable.

If I wire the two 4 ohm DVC subs in parallel, i get an impedance of 1 ohm whereas if I wire them in series, the impedance is 4 ohm.

My question is If I wire them in parallel, will I be overpowering the speakers and what do you think of the low impedance(1 ohm). Will it stress the amp too much or affect the sound quality?

If I wire them in series each speaker gets only 250 Watts RMS. Is it enough or will it cause distortion?

Please suggest which is the best setup for me: Series or Parallel?