Confused with Amps..

Confused with Amps..

I'm looking around trying to figure out what I might want for a stereo system, and I am having trouble figuring all this out. Too many numbers

Anyways, say I were to get this subwoofer: http://www.crutchfield.com/cgi-bin/S-DcMhqOHtfXo/ProdView.asp?s=0&c=10&g=67700&I=1081203DVC&o=p&a=0

Ok, what kind of amp would I need to power it? I'm assuming a 300 x 1 at 4Ohms, right? If that is the case, why not just get a 300 x 1 at 2Ohms and wire the subwoofer into 2Ohms. If that is even possible.

Just a wondering mind that can't figure how much power is really needed

You basically have three choices:

1) Get a mono amp rated at 300 (or less) Watts into 2 ohms and wire the voice coils in parallel. This is the cheapest solution, but amplifiers aren't very linear when driving low impedances, so distortion tends to increase. I'ts not really a significant issue with subwoofers though.

2) Get a mono amp rated at 300 (or less) Watts into 8 ohms and wire the voice coils in series. This will give the best quality, but you're looking at a pretty large (and expensive) amp. An amp capable of delivering 300 W into 8 ohms could probably deliver about 1000 W or more into 2 ohms.

3) Get a stereo amp rated at 150 Watts (or less) per channel into 4 ohms and wire the voice coils individually to the stereo outputs. Do not get the phases mixed up! You also run the risk of having the coils fight each other a little bit if the gain and phase of the amplifier channels aren't exactly the same. I would not recommend this choice.