John Sayers' Recording Studio Design Forum Archive

A member for not even a week and already I'm an addict. Every thread is a great read you guys! Thanks!

So, here's my multiple choice question:

The set-up: I'm building a basement studio. I have 9' ceilings in the basement so I have some headroom with which to work.

Sketch 'A': Here we see my original plan for soundproofing between the basement and floor above. Thankfully, to knightfly in particular, I have learned that three masses is a no-no. Unfortunately, I learned this after applying the drywall to the bottom of the joists... worse, directly to the bottom of the joists (collective groan). Now the question becomes, where do I go from here?

Sketch 'B': Removing the bottom mass. Using the ceiling space for sound control behind stretched fabric. Still no separation between drywall and floor joists.

Sketch 'C': Removing the middle mass.

Sketch 'D': If I understand correctly, three masses are only a problem when each is hermetically sealed. I believe the insulation (it's kraft-faced) acts as an air space. If this is the case, cutting small holes (2"-3" DIA) into the middle mass, say one every two feet in each joist space, would negate the three mass problem. Is this completely insane?

Of course, "none of the above" is a VERY viable option. Right now, my newbie senses are pointing toward 'D'.

Thanks for your valuable input!

Sky

Sketch 'D'

"B" is your best overall choice - you would see slightly better sound proofing by using "C", but you'd get no acoustic treatment inside the room, and you already have 10" depth without the extension; the percentage of air gap increase isn't enough to warrant doing away with the acoustic absorption afforded by "B" - "A" is definitely out, bad isolation AND bad acoustics. "D" is essentially "C", acoustically.

Sooo, did I pass the audition? Steve

Thanks for the reply, Steve. So, even though there's no RC between the gyp and the floor joists you think 'B' would be sufficient (I know it's definitely not ideal) isolation-wise? Referring to the "acoustic absorption afforded by 'B'", this applies to the quality of sound inside the studio as opposed to providing isolation to/from the room above, correct?

You're right that having RC suspending the wallboard below the joists would be quite a bit better, but I was under the impression that it was a "done deal" - if so, and you're not willing to remove the wallboard in order to add RC, then the next question would be just how much isolation do you need?

If you can provide more details of your situation maybe we can get closer to a "real" answer... Steve

Well, the drywall is in place, but I don't want to say I'm past the point of no return... I want to do this right and have as few regrets as possible when I'm done.

Regarding how much isolation is needed: The space above is our den. It's not where we spend most of our time, but our first floor layout is basically one big space with no separations. Plus, the flooring is all hardwood and ceramic tile so it's very echoic (I think that's the word ). I plan on recording drums and amps in the live room. Right now, with just the drywall up, I can hear the footsteps above although very muted. Since I do not yet have the studio walls constructed, it's difficult to say how well sound travels up. I would like to keep much of the sound contained in the studio as possible... for the sake of keeping my wife sane during a session that runs til midnight.

So, is this goal too lofty? Will it be worth the while to redo the drywall w/RC?

Continued thanks.... Sky

If you really want good isolation for drums, you can't be too careful. If your other paths to the rest of the house are tight, then you would be better off removing the wallboard and insulation, and following the modified drawing I did, second one in this thread -

http://www.johnlsayers.com/phpBB2/viewt ... =3182#3182

Your problems as is will be twofold - not enough isolation to keep your wife from handing you a knife and asking what you think is inside your drums... and lack of isolation for footfall noise from above.

Doing everything in my modified version of Dr. J's drawing should solve both of those problems... Steve

Great, Steve! That's quite a detail there. I'll be tearing down my wallboard this weekend... carefully so as to re-use it up against the subfloor. Any thoughts on using construction adhesive to secure it between the subfloor and wallboard?... y'know what, I bet you've already discussed this and I've bugged you enough on this topic.

To quote another thread "I wish I would've done a lot more reading and a lot less building".

Sky

Construction adhesive is fine, squish it down as much as possible and only use it around the edges so the panels maintain their own "coincidence frequency" - improves isolation that way. It wouldn't hurt after the panels are between the joists to put some cleats up against the edges of the wallboard (caulk first, shove the cleats into the caulk and fasten)

"lot more reading and a lot less building" is one of the reasons I'm doing this - made that mistake over 20 years ago and am just now getting close to being able to rectify it... Steve