This may sound stupid, but I need to use my rear channel surround speakers as my "b" speakers as well. I would like to use the multiple outputs on the speaker selector (add on box) for the "input" and the "input" on the speaker selector box as an output (since there is one line in on the box). This would be so I could alternate between surround and the "b" usage on my receiver. Has anyone tried this? Are there any guards against using one this way. I have not purchased the selector box and would appreciate any advice on one less than $100. I have seen them on amazon from 35-85.