| no, please don't replace the rears...in fact, disconnect the ones u have...
music is in stereo, so that's 2 channels: right and left
u don't want more than one speaker playing the same channel and frequency...therefore, u don't want rears (if u do, then the frequencies hit your ears at different points on the sine wave of music, so some frequencies get boosted and some get cancelled {ie rears hit u at low point, fronts hit u at high point, so they cancel out}
in a car, u want 2 good fronts (strong component set: adire, crystal, focal, jl xrs, dynaudio, rainbow, etc) and a sub
if u wanna save boot space, then you get 2 good fronts and 2 6x9s that are made for sub usage, are sealed (build box under bottom of speakers, are sound deadened (use b-quiet, not dynamat) and are xovered to only play lower frequencies (set somewhere around 60-100hz)...u'll then have good audio, although I have trepidations about 6x9s being anywhere near as good as a 10" sub |