BO$E does not make a subwoofer. What you have is called (by them) a 'bass module'. It is designed to fill in the holes you get from the tiny cube speakers (and it does a poor job, btw).
Yes, you can use it as long as you use the cubes as well (and plug it into the proper connections on the Sony). You must plug everything into the bass module or you risk damage to the speakers (plus it will sound even worse). If your goal is to add a subwoofer (using the sub pre-out), then no, it will not work.
David is right you can use the Bose bass module with the rest of your Bose cubes with your Sony receiver as long as your system is the stand alone system that Bose sells as an Bose Acoustimass System. Those speakers are meant to be used as a system, although not a very good one because their are electronics and equalization built into that Bass module.
However if your Bass module and cubes are part of what Bose sells as the Lifestyle system using a Bose receiver then you are out of luck. As that system uses propitiatory wiring to connect the Bass module to the Bose receiver that your Sony does not have.
Thank you Dave. You saved me a lot of $$$ and grief! Does the same thing apply to, say, a Klipsch ProMedia 2.1 Powered Subwoofer (since it is also part of a 2.1 system, or would THAT one work with my 5.1 sysrtem?
I'm not 100% positive, but he Klipsch may work as a sub. It would hardly be worth it. You would need an adapter to make it work and the size and power would really limit the output.
IMO, don't bother. Sell both on E-Bay and buy a real sub.
[SIZE= 16px]The bose base unit isn't powered...even with good power it's utterly lame when compared to a powered sub.The bose system sounds great !...but it doesn't rock.(for this reason my acoustimas system has sat and collected dust for years).[/SIZE]