^^^ No, all 5.1 channels are working....I have it in Pro Logic effects setting. The Amp has two subwoofer outputs...I'm using the top one with a single cord w/rca ends.
The set-up has choices for large or small for all speakers. (not the sub) I have the two fronts large and the backs and center are set to small.
The sub cross-over is set to 80 hz.
I re-ran the calibration a couple days ago and it seems about perfect....except for the sub is not like my Advent was. I watched a couple sci-fi movies that have some great low frequency scenes and if I keep the sub gain down to 3 (out of 10) it wasn't too boomy. Any higher gain would send me hurrying to the back to lower it before something broke....lol
The 15 inch Advent could be felt at lower volumes easily but subtle like. I can't feel the Klipsch like that at all...only at higher volumes.
I can live with it this way....if I can't, I'll shop for a 15 incher.