Hi, I decided to build columns for my surround speakers, which will be Invisa MPX. The columns will be constructed the same as a 2x4 wall studding - 16 inches wide on center. They are 8 feet tall (10 foot wall with a cross brace at 8 feet where the plywood backing joins). I put a cross brace about 2 feet up from the bottom as well and was thinking about potentially putting another one at about 6 feet high. The speakers will be centered around 4 to 5 feet up the column. But then I got to thinking that these speakers may have been designed to have empty wall space between studs. I googled it and another manufacturer mentioned that they designed their speakers to have 3.02 cubic feet of empty space in wall and that if the speakers were to be boxed in (essentially decreasing that space) they would not function as well. So, I am fully confused on what route to take. I can remove the bottom brace that I put in to give me right around 3 cubic feet of free air if that is best. I thought it would be nice to have the cross braces to strenghen the column structure --- not sure if that does anything for vibration or not --- and was going to put some owens corning fire and sound wool insulation in to maybe decrease any echo that the empty in wall space might create --- just not sure what to do.

Any thoughts would be much appreciated.

Thanks,
Buddy