You might, but odds are probably against it. Unless you have a trained ear that picks up on subtle differences, I doubt you'll notice. That said, if you are using a sub for the 2.1 music, then the 6.5" woofer isn't really a necessity. If you were listening in 2.0, then yes, but not so much with 2.1. Why not get the bookshelf speakers from Emotiva and avoid the issue altogether?
It's a VIRTUAL channel unless stated otherwise.