sub question
 

ok right now i have 2 12 inch subs(they aren't that big of a name) they are 600 watts each. Then i have an 800 watt amp which both subs go to.right now they sound pretty good. if i get a 1200 watt amp would they pound better? thanks in advanced for the help

Heh. Not enough information.

power ratings on subs are fairly useless. On cheap subs, they're completely useless.

Just because that sub can withstand 600 watts doesn't mean that it's actually going to produce additional sound. Quite often, some of these "600 watt" subs will reach full excursion with as little as 100 watts, thanks to their weak motor assemblies with flimsy spiders. After that, all the extra power just results in nasty noises from the cone bottoming out.

But... whether or not your amp is actually putting out a full 800 watts might be an issue too. If your amp is a "no name" brand like your subs, chances are you aren't making nearly as much power as you think. If that's the case, then there could certainly be additional output available if you get more power.

What are the brand names for your amp & subs? Knowing what equipment you're using typically makes it easier for people to give recommendations.

the amp is an american legacy 2 (800 watt) amp (www.justamps.com , and the subs are american pro bass machine(WS90) 300 watt RMS, one voice coil and 4 ohms(www.justwoofers.com). Also i have a cross over which i have it set up so only bass is coming out of the subs(unlike some people who have music coming out also). is this all the info u need or is there anything else. one other thing is would u recomend gettin a cap? and if so tell me y and what kind to get

That clarifies things.
Both your subs and your amp are grossly overrated, so upgrading either would probably result in an early death of something.

I wouldn't worry about a cap unless your lights are dimming a lot. That amp probably doesn't draw enough current to require it.

thanks for the help jim, i see why u are a moderator. i have one last question for u. right now i have a rockford foshgate box that holds 2 12s, you said that my stuff is overrated. what would you recommend if i was to upgade it all? I don't have much money so the cheaper the better

anyone have any input

Cruise ebay..you'll find some pretty good deals there..buy from a trusted ebay dealer and you wont have problems. Get a good brand name, and you'll be doing good.