Single Sub Woofer for two separate systems?

Is it possible to use the same SW for an HT system and a separate audio system?

I was wondering if you can connect a single SW RCA cable to my HT and continue using the dual wire method for my separate audio set-up comprising of an Audio Research D90 amp and SP12 preamp? The SW supports both a single RCA input and dual speaker wire inputs.

Of course not having both systems on at the same time.

Thanks