I'm not sure I followed what your set-up now is - are you using a pair of wireless speakers for the back surrounds (channels 6 and 7)?
I'll have to try doing that. I'm just running a 5.1 set-up, but also have a pair of wireless speakers that I usually just use for temporary use outdoors. I run them off the "rec out" jacks, so they are getting the front left/right signals. Thus I can have music on my main speakers indoors, and the same music playing out on the patio for a party.
I have a Yammie receiver, so I should try using the pair of wireless speakers as either a set of back-surrounds in a 7.1 set-up, or else as the "presence" speakers in Yamaha's proprietary "presence speaker" set-up.
One interesting thing I found is that both my wireless speakers (which are Advents), and a set of wireless headphones that I also have (JVC), use the same freuqency range (900 MHz), as well as the same modulation scheme, and so both products will work with either product's transmitter. (In other words I just need to have one transmitter hooked up, to use both the speakers and/or the headphones.)
I have also seen a description of a two-channel wireless "link" from Kenwood, I think, that is meant to be used with a pair of regular speakers. The "wireless receiver" part of this product sits where you want to place the speakers, and contains a pair of modest-size amps to drive the remoted speakers. In theory this would let you use better-quality speakers. I assume the frequency response is somewhat limited - these products never seem to say what the actual frequency response is!
