Practice studio construction guidance (page 2) | John Sayers’ Recording Studio Design Forum archive

Well the project is complete. We were asked to turn a CMU outbuilding into a "bomb proof" (bombs going off inside) practice room for this metal band in a very ritzy neighborhood. Thanks to Stuart and others for your help. We were shooting for 65-70 db of isolation (well I was, nobody else even cares what that means) because they needed Live at Leeds db levels inside to yield whisper quiet levels at 50 ft. I interpreted that to the above targets. They are not technical clients and wont even make the time for isolation measurements to determine the outcome but they are extremely happy. Chaos inside and everyone says amazingly quiet outside. The approach: Single rectangular room, no focus on ratios. Common monolithic slab floor. Sealed external windows with poured concrete. Inner room with 10" air space to block wall, 12" air space to original ceiling, everything filled with fiberglass insulation. 2x4 wood stud walls, 2x10 wood ceiling joists. Inside of exterior wall painted twice. Original ceiling cladded in one layer of OSB and 2 layers or 5/8" drywall. Inner ceiling and walls all 3 layers of 5/8" drywall, staggered and sealed, all 2 leaf. HVAC isolated with a flex duct. Solid wood doors with good exterior seals. They did not follow the recomendation to add additional MDF to the doors for mass and extra seals. Bamboo engineered flooring floated over a foam membrane for moisture. Total spent around $50K US. Fought conventional construction techniques the whole way. Wanted to add drywall on all sides (3/4 leafs). Wanted to add foam board and drywall to the inside of the outer wall. Said it was too cheap as designed. Did not want to seal at each drywall layer. Connected the leafs at the doors with solid wood (made them tear that out). Never did add mass to the doors. If you do this for a living it must be like hearding cats. I felt like Copernicus trying to convince people that the earth revolves around the sun. It almost all got done right and everyone is happy so on to my project (seperate posts). There will be a lot of personal involvement when the next one gets built. Thanks again to all who helped.