If you want to put in a center speaker and have no center channel output, try connecting 1 lead of the center speaker to the left front + and the other to the right front +. this may create a real neat effect tht sometimes sounds kind of like a reverb. I have done this many times and it sounds good unless you are listening to a weak fm station and then the hiss may be worse from this speaker. try it and if you dont like it take it out.
wb5oxq, jim in waco, tx.