Thanks for the replies. Looks like 2 different suggestions. Yes, the Behringer A500 has the bridge/stereo DIP switch. So if i get this right, Gonk and Otto suggest, bridging the amp and running all four speaker wires (bi-wire) to the bridge (the middle red and red). In the A500 this would be channel 1 and you would put channel 2 volume off. I looked at the EP2500 manual and I don't see how a mono input can drive both channels (ie in stereo).

Altec, your suggestion is also to bridge. But hook first pair from the center to channel 1 (normal polarity), and second driver to channel 2 (in reversed polarity). I'm assuming you would then keep both channel 1 and channel 2 volume controls turned up, correct?

Thanks much for the replies, finding the various options a bit confusing. Will try both ways and see how it sounds, the reversed polariy kinda scares me a bit, but Altec sounds very convincing :-)

This weekend, hook up center and 990 firmware update, fun fun :-)