An enclosure around your system will boost the bass response from the speakers (if you soffit mount). Pine wood would not be my first choice. My first choice would be heavy MDF board for cabinetry with a nice hardwood for the visible surfaces (for aesthetcis and such that it does not vibrate ...dead sound when rapped with your knuckles).
None of this will help with Mid range intelligibilty? Are you using phantom? The center channel information needs to go somewhere if youu don't physically have a center.
None of this will help with Mid range intelligibilty? Are you using phantom? The center channel information needs to go somewhere if youu don't physically have a center.