Good day to all Not long ago, I had a very informative discussion with Audyssey guy Chris Kyriakakis, asking him if I can use a pair of dipole speakers as Back (Rear) Surrounds. In the same discussion (link = http://ask.audyssey.com/entries/208239-dipoles-bipoles-or-monopoles-for-surround-speakers), I gave him a brief description of my system, explaining that I intend to use two center speakers instead of one, placing them side-by-side on the rack, in front of the front seaters and under the center of the screen. Mr. Kyriakakis returned to me by NOT recommending the use of two center speakers, claiming that this would create a "comb filtering effect". Although I explained that the main purpose to use two centers instead of one is to close the "gap" between the two front main L-R speakers, ude to their difference in size and therefore in SPL and soundstage, he insisted not to do it. Briefly, my system consists of the following: - A pair of Mirage M3-si front L-R (floor standing-bipolar) - A pair of Mirage M5-si Surround L-R (floor standing-bipolar), placed behind the seaters, at an angle of about 30-40 degrees from the "sweet spot" - Two Mirage MC-si speakers (normal bookself-bipolar) as front center ones, driven by separate power amplifier channels, which shall be fed by the same porcessor signal from the AV pre-pro (Onkyo PR-SC5507). - Two Mirage OM-C2 speakers (larger bookself-omnipolar), hung from the ceiling on specially made stands, above the the front main L-R speakers, as front height L-R ones. - A pair of Paradigm ADP-190 dipoles (small bookself), also hung from the ceiling on a special stand, located at the center of the space, behind the seaters and at about the same height as the front height ones. - Separate power amplifiers for all speakers. However, as I said above, Mr. Kyriakakis told me to abandon the idea of the two front centers, due to the possibility of the "comb filtering effect" creation. What is your opinion on this? Thanks in advance.