Noticed something while listening to a DVD-A disk using the 6 CH Bypass. While listening I decided to check the speaker levels and when I hit CHANNEL CALIB I got the individual speakers playing their dircrete music instead of the test tone. I'm sure others have seen this but I just found it interesting. Don't know what good it is except maybe to check bass levels going to the center or more importantly to verify the stereo subs are working. Only seems to work in the bypass modes.