raising subwoofer off floor by 20 inches

Sounds odd to me. Most sub's are designed to be on the floor. Raise it that far off the floor and you'll probably screw up the bass by creating a large suck out.

Exactly whats your problem anyway. List your equipment, room dimensions, speaker locations, listener position and perhaps some one can give you some specific help.

I don't know about such a plan. Is it a downfiring sub? If so, it probably should be on the floor. As far as blending better with your mains, try lowering the crossover point. If you want more punch, turn the sub up or place it in a corner.

I just looked at your system. Your bass graph shows some fairly flat bass. Where is it crossed over? All I can see is an expected droop below 32hz and another droop up about 200hz. What am I missing. Are you trying to get more bass on the 25 to 32 hz area.

I noted some control sliders on the graph - are these actually equalizer controls that you have used to get the bass response that you have? I'm confused (nothing new).

I remember seeing an article in one of the rags about a subwoofer stand. I only skimmed it, but I do remember that they did think it made an improvement. I don't remember what sub they were using or anything else. When I get a chance, I will look for it again.