This past weekend I got to play with my system a little bit. I had all of the speakers calibrated to the AVIA DVD and wanted to see if there was any difference with the internal receiver test tones. With the receiver at 00, the left, center, and right channels were great. The rear channels were a bit off. Then the sub channel came on. The sub was a few dB’s higher so I made that level with the main speakers at 85 dB. After the calibration, the bass had more range than before. It seemed like the AVIA disk calibration was is using lower bass frequencies to for sub calibration. While I was listening to some bass heavy music on Saturday, the music was awesome and I could hear and fell all of the frequencies played. I have not tried movies with that setting but want to soon. It seemed that the AVIA subwoofer tone played lower frequencies making every bass scene I watch shake everything (which is fine with me) but I wanted more bass range.