I had written in an earlier post that I was going to bi-amp my front M80ti speakers. The Denon 3805 I have is a 7.1 channel AVR that I am using in 5.1 channel mode (because I don't have space for 7 speakers!). The unused two back channels are now being used to drive the woofers in the M80ti towers. And on the Denon 3805 I can adjust the levels of the woofers separately from the that of the tweeters! That's pretty cool! I can immediately hear the difference in the sound.
I know this is not rocket science, but I am happy!