i just bought a polk momo 12" sub and want to get an amp. the sub is rated at 500 watt rms; i am looking into upgraded speakers. my question is, will a 5 channel amp- like 500 watts for the sub and 400 watts for the speakers- sound good with a good amplifier? or am i better off getting a momo amp for the sub and a 4 channel amp for the speakers? thanks a lot !