I'm planning to build corner bass trap panels, based on what I've been reading, measuring 24" across, using 5" of roxul rht40. They will go floor to ceiling, and I want to do panels because I'm not quite willing to commit to a more permanent built in trap filled with loose batt material. Question is...should I face them on one or both sides with 6 mil poly as suggested in some discussions? My other treatments so far consist of 6( 3 each side) first reflection absorbers 2" thick, 2" standoff, rht 40. Thanks for your interest and help.