I just received my subwoofer yesterday. The 20-39 PCI model. It is so big it looks like a water heater. It sounds pretty good but know it would be better if properly calibrated. All my speakers are calibrated throuh AVIA but when it comes to sub calibration I'm at a total loss on how to do it. The very first thing is the left-main/subwoofer. I'm able to get these two about the same db level through the SPL meter (albeit when the sub is heard it jumps a little above and below where the left main speaker is). Then when you move on to the center channel and right speaker the sub level is significantly lower than those channels. So my question is this. When you adjust the sub for those channels you change it for the one you previously did. So I am very confused. I wish there was just one sound test tone out of the sub instead of all this other stuff I don't feel necessary. My receiver doesn't have a test tone for the sub and besides that I wouldn't trust it anyways as AVIA test tones were way different than the receivers. Please shed some light on this subject. I have done forum searches but I haven't found my answer. I am not the most technical person so guide me through this process like a baby.