Good evening,

Currently in the design phase (in fact, my design link is already old, I convinced the wife to let me build a dedicated room at the other end of the basement) and looking at a 22' x 12.6' room. 2 of the walls are of the concrete/underground variety. From what I understand doing double drywall and green glue is for sound isolation purposes, but is it necessary for these kind of walls? Since the walls are underground, I would think that doing this treatment would not be necessary.

However, will doing DD/GG on the ceiling and other 2 walls, but not the concrete walls create an imbalance? I thinking that as long as the acoustical treatments inside the room are balanced, the isolation treatments shouldn't have a negative effect.

Thanks!!!

Do a search on here and on the GG site for a term called 'flanking'. That will give you a better understanding for why you do all of the walls and ceiling. Basically, the sound waves can easily travel along concrete walls, and go around the walls/ceiling that you made into a DD/GG sandwich.

The GG Flanking page:

http://www.greengluecompany.com/understandingFlankingNoise.php

So basically the insulated space between the non double drywall and the concrete will create a cavity by which sound will leak to the upper floors. Got it! =)