However the improvement in low frequencies is substantial.
My house is 85 years old and the original oak floors are a little creaky. After performing a bass crawl the sub was moved from the front corner to a rear position behind the sofa. The new position was a big improvement in overall bass response. Although the sub is crossed over at 80Hz, it could still be localized behind the sofa, which at first I thought was impossible from what I read and really annoying for music. It turns out I was hearing resonance from the old floors. I started researching subwoofer isolation and read about the auralex gramma and recognized this is exactly what I needed. Which I plan on buying... maybe.
The temporary solution is a piece of 2" high density foam left over from my wife's contrabassoon travel case modification. Turns out the foam was exactly as wide as the T250 and I folded the edges over in the front and rear. This foam eliminated the floor resonance and more importantly bass now sounded like it was coming from the front speakers. However the foam seemed to reduce output, but it was floor resonance SPL I was missing. Bumping the sub channel from -6db to -3db fixed this problem. Wow clean, tight, non-localized POWERFUL bass!!! I'll need to re-audessey.
I may use this foam to create my own gramma. If it fails WAF, I'll just buy a gramma or subdude. Any other nice looking option besides the auralex solutions?