raising subwoofer off floor by 20 inches

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.

All subs should be off the floor by approximately 27-31 inches. This idea is from ASC (the tube trap people). It works by minimizing standing waves as low frequencies and providing better coupling of the woofer drivers with the room. ASC makes a special tube trap to elevate your subs off the floor to take advantage of this idea.

I should note that the height off the floor and distance into the room can vary depending on ceiling height.

thanks guys for your comments!

i am actually quite content with my setup. the suggestion came up during a casual conversation with a velodyne dealer (i was trying to get a good deal on a second dd-12). so i figured why not ask my fellow audiogoners before i try out the placement.

Newbee, i am sending full signals from source to both main amps and subwoofer, which is set to respond to 60hz and below. the sliders are indeed equalizer adjustments made to achieve the somewhat flat response. my current goal would be to achieve similar or better results without adjusting so much of the equalizer settings.

thanks Hifidreams and Etbaby for your info. the asc subtrap is quite interesting.

>>All subs should be off the floor by approximately 27-31 inches<<

Really? On what empirical data is this based? Interesting that Velodyne, Vandersteen, Kharma, etc. don't recommend this, only ASC. I'm sure it has nothing to do with their special tube trap that elevates the sub.