so would this be a good idea or bad? regardless of whatever head unit I got (it'd have to depend on my speaker output) But from my left over car stereo, I've got 2 10" pyle drivers and a 700 watt amp(12 volt but a transformer wouldn't be a problem with a good fuse). Any way if I got another 15" say put it in it's own cabinet and put two two.. say 3" ports adding breath ability and snagging a coil to to say 80khz and then the two 10s in their own cabinet ported 3" probably a 4 foot box would give it proper volume properties and capped those off at 40mf.. hmm what do people think? Is the 15 coiled to low? and to get the higher octives should I throw some 6's in there capped at 200khz? Oh and of course the wood is MDF.. throw some carpet on there to make it look nice, platic port inserts... and maybe some poly covers to guard against any road damage..