Here's a link giving an example of what I'm describing. http://www.hometheaterhifi.com/volume_9_3/feature-article-multiple-crossovers-9-2002.html
Start reading about 3/4 the way down, starting with the topic line: Mixing high and low frequency crossovers in a multi-channel set up.

So I guess if I were to get the M80's I should cross them over at 80hz for home theater use, maybe lower for 2 channel/direct mode (provided I get acceptable bass response). I do have a Radio Shack SPL meter and Digital Video Essentials for calibrating, by the way.

I guess what this boils down to is would upgrading to M80's be a significant improvement over M22's?

M80v3s, M5HP, QS4s, M22s, EP350v3, Denon X3700H