+1 georgehifi
Agree, use PreOuts. Last thing I'd want to do is to route a quality amplifier's speaker outputs and signal into yet another layer of cheap electronics, connectors, and crossover inside a subwoofer, and then on to another set of speaker connectors and speaker cables out to the speakers, thus further degrading the signal/resolution/detail to the main speakers. Best to try it and compare. The comparison results can be notable. Good Luck.
Agree, use PreOuts. Last thing I'd want to do is to route a quality amplifier's speaker outputs and signal into yet another layer of cheap electronics, connectors, and crossover inside a subwoofer, and then on to another set of speaker connectors and speaker cables out to the speakers, thus further degrading the signal/resolution/detail to the main speakers. Best to try it and compare. The comparison results can be notable. Good Luck.