Does anyone know of some good SQ 6.5" bi-amp capable components that aren't too expensive? My budget would preferably be something under $350. They would be powered by the 75W RMS X 4 channels of an Alpine PDX-5.
All components are biamplifiable you just need to add an active crossover which is connected between the source signal (usually the output of your HU) and the amplifier, the included passive crossovers are not used.
All audio equipment parts sound different and component speakers are no exception, I'd say as general guidelines avoid the entry level line of any company and expect to pay at least $200 or so for a set.
If you want a few common SQ brand names look for Rainbow, Focal, Morel, Cdt, DLS, Hertz, all will have something in your price range.
I like to consider components that have strong midbass performance which blend in nicely with your subwoofer.