i have a small pioneer 2 channel 200w amp atm. right now ive just got a **** head unit and some 6"s in the back shelf. im getting a good head unit and gonna stick my other 6"s in the front doors but will the amp be ok for a sub? what size/power sub would be suitable? not looking for the loudest stereo in the world just wanna make the best of what ive got.
Is it 200W max? or RMS? 200WRMS is a damn nice amp, so i'm gueesin its 200W max. In that case, its prolly about 50WRMS per channel. It should be cool, if you bridge it into one channel, to run a 12". Even a 15! just be sure to get a relatively low power rated sub. A kicker EX124 is a damn sweet sounding 12" sub that'll run quite well off that sort of power. Just make sure you get it installed properly. Build a large sealed, or a ported box. Small sealed boxes actually improve the power handling of the sub, meaning tour amp may not run it well enough.
Hope this helps!
Oh and by the way, due to the nature of low frequencies and subsonics, it won't really matter where you put the sub. If you install it in your boot, it'll sound the same as if you install it in your parcel bench (provided they have the same enclosures). The only difference will be that if it is in your boot, you won't be able to feel it pushing the air around you, which gets annoying anyways.
Oh, and if you fire a sub straight into your rear glass, your windscreen will start to reverberate and magnify a certain frequency of bass. This can really sound wierd because one frequency will be much louder than all others.