newbie design

[knightfly]

Sorry, been swamped lately and missed this one;

Ideally, the only places you should have mass is at the outside of the outer wall, and at the inside of your inner, studio walls; anything more will compromise isolation to some degree at a couple of undetermined frequencies.

If it were me, I'd leave the sheet rock off the frames that border that hallway until last; then do some tests with known levels of bass inside, cranked until you can just hear it outside; note the SPL that was present in the room when it became barely audible outside.

Then, add a TEMPORARY layer of sheet rock to ONE of the hallway frames, and re-run the same test; there is a good chance you'll hear it outside with LESS SPL inside. If so, the sheet rock on both sides of the hallway should be replaced with something like perforated masonite, or something ELSE that has lots of holes.

By "temporary", I mean all you need to do is lightly tack up the sheet rock against the studs, using only one screw per 2 feet typically; no caulking needed, just tack the stuff up on the studs horizontally, top board resting on the bottom one, and do the test. If your hallway is narrow enough to cause a multi-leaf effect, you'll know it by your test results.

I can't calculate whether your results will show that it's OK to put the extra layers on your framing, but these tests will be cheaper/easier than going ahead and adding both those extra leaves, only to find out your isolation isn't as good as it should have been... Steve

[vair327]

What do you think of half sheet rock,on the bottom, and half peg board, on the top, with the peg board covered in fabric? Do you think this will solve the problem?

I thought that your idea was good but what about the run away guitar amp running into the wall. The rock on the bottom should give the wall a better chance, and easier to repair.

Hey and thanks for all your help. This is such an awesome place to be a part of!

It will be a while before this project will be built, we are still getting funding for it in the form of grants. It will be, as far as I know the only nop-profit studio in California. It is geared towards helping High schools, college, and local bands to get their music down on cd for demos, college entrances, honor band type stuff, and of course for fun all at really low rate.

[knightfly]

What do you think of half sheet rock,on the bottom, and half peg board, on the top, with the peg board covered in fabric? Do you think this will solve the problem?

No, any section of the wall that has an extra leaf of mass between inner and outer leaf (in this case on opposite sides of the hallway) will act as a multiple leaf partition, and be weakened at lower frequencies.

I thought that your idea was good but what about the run away guitar amp running into the wall. The rock on the bottom should give the wall a better chance, and easier to repair.

First, this is a hallway; any "runaway amps" should be going faster ALONG the wall, so would give it more of a glancing blow; second, you can also get 1/4" pegboard, which would be stronger than the 1/8" stuff. Thirdly, if you're REALLY worried there is always expanded METAL, at least for the lower half; also, it's easier to replace a section of perf board than to re-intall, te-tape and texture, and repaint gypsum wallboard.

Finally, if you will need good isolation from studio to outside while the hallway doors are open, then forget all the above; in that case, you would need to widen the air gap between the innermost mass in the studio and the beginning of the hallway; in other words, build your mass-air-mass wall INSIDE the building, and ignore the hallway; just build it normally, put extra mass in the m-a-m wall at the rear of the studio, and that way you will have best isolation with the hallway open to the outside world... Steve

[vair327]

So what you suggest is som thing like this?

[sharward]

Maybe I'll come out to The Boardwalk on Thursday the 19th to see you guys play!

[knightfly]

"So what you suggest is som thing like this?" -

Unless you need good isolation to the outside world from the studio while the hallway doors are OPEN - yes, that's what I meant... Steve