Looking into feasibility of converting a detached garage into a one-room studio. What I'm grappling with right now is what to do with the existing exterior 2 x 4 stud wall (12" on center) with wood lap siding. I'd like to achieve 50 STC (neighbours are 40' away in either direction) from a sound proofing perspective and keep it as insulated as possible for heating/cooling.

While waiting for Rod's book to arrive, I saw this page and was wondering what makes the second construction design superior to the first one:
Safe'n'Sound Ratings

Anyone?

Pretty much the stud spacing for the final drywall attachment - all other things being equal - a wood framed wall with RC will be about the same level of isolation as a light gauge steel stud given the same spacing - as the spacing increases you get a benefit in LF isolation levels.

Rod

Thanks Rod. Do you think it's worth it in terms of R-value and STC to going with a "partial" double leaf design?

i.e. adding insulation between existing exterior studs + air gap + interior studded wall, insulation, and two layers of 5/8" dry wall to complete the double-leaf design? Assuming the exterior wood lap siding/plywood is equivalent to two layers of 5/8" drywall, I should be in the neighbourhood of ~60 STC according to various charts on leaf design I've seen.