I have a friend who is interested in hooking up a third speaker (4660 JBL) into his stereo system. I told him that I remembered a technique for this very thing that was done in the old days. I don't remember what it is called or how to do it. All I remember is that the third speaker is powered by taking the + from one channel and the - from another. Does this sound familiar to anyone? Please let me know if you can help. Thank you, Steve G