Double width studs for isolation?

Staggered studs is the most insane thing I've heard from a construction standpoint. Not only would a building inspector frown on this, your electrician would kill you if you ever needed any work done. You couldn't hang anything in that room ever because you couldn't confidently find a stud? You can add extra studs at a staggered rate within your 16's, for that matter, you could even stagger steel studs within wood ones?

Yes, I've built clubs. 18" of concrete won't even stop the problems. Eldaford is correct that you should be 16" on center for studs, period. Keeping speakers from being mounted in any way to a wall will reduce the bass transfer.

Doubling the interior drywall helps. Make sure you tape and mud the first layer, then hit is with a second layer. Stagger the drywall seams and not only screw but also glue the first layer to the studs. Ideally if money, time and space didn't matter, I'd build a double wall with the inside wall completely decoupled from the outer wall, built on rubber seams and a false ceiling too-this is only a pipe dream.

Magfan, I totally understand the "sound" engineering. However, having renovated many buildings, I know what it's like to have to open up walls to search for studs. That's why I'd push for either 16" studs with random in between or at least a pattern to aid in future finding of the studs?
If I was buying a property with random studs this would greatly devalue the property and would be considered a "knock" down on any wall unless plans were available with exact dimensions and proof of proper construction by a qualified contractor.

Magfan, great concept now that I understand you. That makes much more sense. It will take some talent to build...