What is the difference in sound in the 2 ohms vs. 4 ohms, cause you can get more power out of 2 ohms on an amp, so why not go 2 ohms, is 4 ohms any better? What do most people use?

 

if you get a reputable amp, you wont notice a difference between 2 and 4 ohm readings.. also, sometimes amps are rated at higher distortion (THD) at lower impedances..

 

oh ok....so i should prolly stick with 4 ohm?

 

not necessarily. are you talking subs or full-range? if you buy a reputable sub amp, such as jbl's BP-series stuff, you can run fine all the way down to 1 ohm. if you give some more info then we can help you out more.

 

well, i dont exactly know what to put, but i got 2 infinity kappa's in the back, and i'm gettin an alpine type-R 10" in the back, and i might be gettin a separate amp for just the sub, and since you can get more power out of 2 ohms, i was thinking i would get a 2 ohm sub, to save money....does it sound any different?

 

you won't notice a difference in quality, except that it will be louder

 

also, make sure your amp has the ability to run in 2 ohms bridged or is a Class D

 

Just to sum up what seems to be scattered all over this thread:

No difference in sound quality. The damping factor of an amp gets cut in half every time you halve the impedance, but anything better than a Pyramid amp will still have a high enough damping factor that the difference will be inaudable. THD numbers will be so ridiculously low with any amp that you can completely ignore them.

The main problem is that a LOT of amps can't handle a 2 ohm load. When you run subs, quite often you parallel-wire them and bridge the amp. Parallel-wiring 2 4 ohm subs will result in a single 2 ohm load. This is a load that's very difficult for most 2 channel amps to handle in bridged mode. because it's the equivalent of a 1 ohm load on each internal amp. You either need a good high quality amp that can handle that, or you need a mono amp. Mono amps, especially class D, offer a lot of bang for the buck, but have ZERO flexibility in terms of upgrade usage. It is and can only be a subwoofer amp.