Thanks Adrian,

The bass from the M80s is amazing. The 150 sounds good sitting in front of it about 11 ft away, but if I sit 5ft left of center, the voices become hollow. Sounds as if the voices are coming from back of TV.

The 150 sits just below tv on shelf about 3ft from wall no back on shelf. I took a listen on hands and knees behind center speaker sounds as if there is a hole in back of speaker. I did not have this problem with my other center.. Any thoughts on this?