Difference between sound and power 2 ohms and 4 ohms subwoofers?

you need a top notch amp to be stable at 2 ohms. whether it is rated so or not. an orion will deliver what it claims over the long haul where a pyle may not .. a cookie cutter name like sony and kenwood definitely not.

A 2 ohm sub and a 4 ohm sub will sound exactly the same given the same power. The reason for different impedance subs is to wire them up to an amp. An amp running at 4 ohms "may" last longer then an amp running at 2 ohms but this is not a guarentee. The reason is that an amp running at 2 ohms will work "harder" then an amp running at 4 ohms. I would not worry too much about the difference though if you have a decent amp because the difference is going to be small. If you are looking at one of those subs then look at the DVC 4 ohm version. Then get an amp that runs near the RMS power you need at 2 ohms. The Kicker ZX750.1 is a good amp for those subs. http://www.rockfordfosgate.com/rftech/woofer_wizard.asp?submitted=true&woofer_qty=1&woofer_imp=4

When subs are wired to 2 ohms, the amp gives them more power, but it also causes the amp to work harder, which makes the amp not last as long as wired to 4 ohms would. But the Pro is, when wired to 2 ohms, you get more RMS then 4 ohms because the resistance is less. Make sure your amp can be wired or bridged at whatever you plan on running. Here is a guide for wiring subwoofers: http://www.RockfordFosgate.com

4 ohms is louder, it gives more of a punch. i had one running at 3.5 and 4ohms with out a divider in the same box and when i turned it up too loud one would make a popping sound. Do that for long and it will blow the weaker sub or damage your amp.