The best way to set the channel levels is through respected calibration software, such as the Avia Guide to Home Theater DVD available here, and an SPL meter such as the $35 analog meter (model #33-2050) available from Radio Shack, which as of this writing is on sale for $25. Depending on your receiver, you might also be able to generate test tones internally but, with few exceptions, would still need the SPL meter.