The AVIA Gudie to Home Theater DVD has a good subwoofer set up section with test tones. I used it to set phase and the sub level (while keeping the sub outpt on the receiver at 0 dB). You don't need the AVIA to set up the other speakers but I found it invaluable for the sub (and for the TV). It's $38 on amazon.com, which may be less than the sub cable that you use and will probaby do more for the sound