What type of car amp to buy

[theboybeast]

I have a sony xplod headset which has a pair of pre-outs and a mono subwoofer out for RCA leads on the back of the unit.  I have a sub already and need to buy an amp to power it, i'm not interested in powering any other speakers in the car so my question is this - if i use the sub pre-out can i only use a monoblock amp or can i just plug the RCA lead into 1 imput on a bridgable 2 channal amp? 

[Potatoman]

99.99% of amp have a filter switch - you choos LPF (Low pass for bass) or HPF (High pass for 6x9's etc). I have Sony xplod mp3 player - i use the sub out to feed the amp - the benefit of this is that the sony headunit lets you control the sub volume in-car - useful as all music sounds different (some songs will boom you into next week while others need more bass). You dont necessarily need a filter - the sub output has that built in the headunit. Forget theother output. Most amps let you bridge the outputsif your only driving a sub. Youll be hard pushed to find one that wont. And make sure the sub wattage is roughly twice that of the amp or u risk blowing it to bits!