[EduardoApolonia]

Update on the room problem diagnostic:


One of the worst problems I have is caused by the speaker placement. The problem is what is called SBIR (Speaker Boundary Interference Response) or Allison Effect.
The first person to make me aware of this effect was Barry Ober from Soundoctor - Home, I contacted him because of the JL Audio Subwoofers and he made some huge comments about my problem, and possible fixes, and also sent me a test cd. He did all this and I didn't buy him anything.
Excellent service!!!!

This SBIR is caused by the distance (1/4 wave length) from the woofer to the near walls, ceiling and floor.
You can read about it in this RPG pdf
http://www.rpginc.com/news/library/PS_AcD.pdf
and on the GIK website:
Learn what is SBIR (Speaker Boundary Interface Response).

In my case the distances from the back wall, side wall and ceiling from the woofer are almost the same, one of the measurements I did was a scary coincidence, the measurements showed differences of this 3 points of only 2cm!!!! as you can see in these pics:






84cm is 1/4 length of 102Hz.
That is +/- where I have the dip.

Then the length of my room creates a dip mode of around 105Hz if I remember well.
The width of the back of the control room creates a dip mode at 107Hz

The crossover of the sub to the mids woofers in the Barefoots is at 110Hz.

So it's a hand full of bad coincidences.

I'll keep this updated for more diagnosed problems and the possible solutions