I'm sorry I just signed up for Audiogon forums. I hope I'm not too late. I just bridged my Pro Power Fours a few months ago. (Two amps into two speakers) I no longer have them bridged. Now I bi-amp them the sound is much better. But I also have a Pro Control Four preamp that has the instructions in the owner manual how to bridge the two. With Soundcraftsmen's Auto Bridge you get three times the power vs. two times on most. You can get the Auto Bridge unit separately that does the same thing. Once in a while you can find them on on-line auction sites. Just let me know if you need the instructions. I can get it to you.
