Forgive the newbie questions ... I'm after an iSub to complement my cube. If I understand things correctly, an original iSub will work with a cube and it's USB speakers but a more modern one (sold as part of a soundsticks setup) won't. The iSub offered via Apple states that it does work with a cube - but the one on HK's site states that it does. I've seen a couple on eBay too - so, what are the pertinent questions I need to ask someone to be sure I get one that works? Thanks in advance Tom