Sound System!!

OK i have a 98 grandprix GT. 4 dr sedan and im lookin into putin a new sound system in my car... i want to put a sub like this...http://www.circuitcity.com/IMAGE/product/enlarged/jsn/EC.JSN.BP212.RT.JPG.. in my trunk.. what amp do i need? mono.. two channel.. i have no clue... and for inside speakers i was going to replace both backs and both fronts.. i already replaced the indash stereo with a stereo cd player that has a built in amp.. so i think i should be alright?

lemme know!

thanx
~GR

Depends what type of sound you want.You should be fine with above 600 watts. I actually have 2 12" MTXs in my car and all I have is a MTX 250 watt rms pushing them and they sound just as good as my brother who has 1600 watts pushing.

IF you want to replace your decks and/or doors, powering them off the head unit isnt a good idea. Your going to want to run two amps, one 4-channel amp for the mids and another for your subsystem. for the subs, mono blocks are nice if your throwing one sub down, for the two sub setup you got i'd go with a 2-channel amp. This way you'll have the option of bridging it and connecting the speakers in serries, or a paralell connection one speaker per channel. Im pushing a 12" Alpine Type-R DVC in my 98 GP GT Sedan and its plenty of bass, backs up the rest of the system fine. Im using an Alpine MRV-T500 for it, 500 watts bridged.

how many watts should i go for with the sub two channel amp?

All depends on the RMS of your speakers. Your going to want the amp to match the Subs HMS, and more importantly RMS raitings. A single speaker raited at 500RMS, would work with a 500RMS mono block, or a 2-channel 250RMS X2 bridged amp. and so on...