kev, you are right - up to a point. you need an *excellent* crossover, usually not found on active subs, and you need two subs. that way, no tweeking, once it's set-up properly. my sub system consists of a pair of vmps larger subs, a marchand xm-9 deluxe x-over (24db/octave, adjustable x-over frequency w/plug-in chips, adjustable volume for bass/treble/crossover-point), and a pair of bridged adcom gfa 555 amps. everything was purchased new, w/exception of one of the amps (the other, i paid $450 for, back in '84!). the total expenditure was ~$2400. the only time i've had to fiddle w/the x-over, was when changing the monitors. never had an integration problem w/this set-up. doug