is it really a 3-panel partition?

[duxsmer]

ok. i know a 3-panel partition is bad given this link...

http://www.noisecontrol.net/myths.html

what if your 3rd partition is a leaky plywood shell? for example, my garage has 1/4" plywood around the exterior, and i'm sure it does NOT exactly provide a tight seal via caulking. read this from Jeff Cooper's "How to Build a Recording Studio"...

"Even a tiny air space such as one square inch can let in as much sound as the entire wall adjacent to it."

if my plywood exterior wall doesn't have a one inch hole, then i believe it's at least probable that my exterior plywood wall has a collective one inch hole because it has not been sealed well.

i'm suggesting to build a one partition wall inside inside my existing room because it would be much easier and possibly have better soundproofing qualities. in other words, since i have a leaky exterior wall with lower density and mass than drywall, i would not be building a 3-panel partition. i would pretty much be building a tight 2-panel partition.

on the flipside...
if i were to tear down the interior drywall, seal the exterior plywood wall, and build a new isolated partition from the exterior wall, i seriously doubt that it would provide SIGNIFICANTLY better sound reduction than the previously described method. this is again because i have a have a leaky plywood exterior shell that can more or less be ignored as a real partition.

thanks for your responses!

[AVare]

ok. i know a 3-panel partition is bad

There is your answer. Your "leakiness" is enough to reduce isolation, but it does NOT reduse the coupling of the leafs.

Andre

[bert Stoltenborg]

Your construction could even hehave as a tuned enclosure, a kind of bass reflex cabinet amplifing low freq sound.

Bert

[knightfly]

Dux, please read and FOLLOW the steps here

http://www.johnlsayers.com/phpBB2/viewtopic.php?t=3231

So we can get a better idea of your situation; EVERY step is important, please do all you can.

Where in the world is 1/4" plywood LEGAL for exterior siding?

Bert and Andre answered the rest; at resonance, whatever that is, your wall would be several dB WEAKER. Better to find a way to "beef up" that outer shell, leave a large air/insulation space, and build ONE more heavy leaf.

Also, ceilings are just horizontal walls; same physics applies... Steve

[duxsmer]

you make it sound as if i've got no clue. just because someone asks a question that seems redundant to you, it doesn't mean you automatically treat them like a newbie. i obviously haven't learned everything there is to know, but i HAVE read a lot of forums. i HAVE been reading books. so i missed something. you can't expect everyone to read and memorize every thread here. i thought long and hard about that post. if i want to post a question, i shouldn't have to search high and low through these threads in the hopes that i'm going to find the exact answer to my exact question. the truth is i don't have that much time and energy. it's a lot easier just to post. my question was not too general, and the short answer of "you're wrong" is fucking fantastic. i got excited. i thought i was onto something. so i posted.

don't get me wrong. i DO appreciate the help from everyone. i wouldn't ask you guys if i didn't value greatly your responses. my follow-up question is...how do i beef up the outer shell besides caulking? any ideas?

ps - i've got vinyl siding over the plywood that will not come down.

[AVare]

you make it sound as if i've got no clue

Steve did nothing of the kind. However you are succedding at making yourself appear to a child. The post that was linked for you includes asking that location data be given (which you did not), and that as much detail as possible on your specifics (which again you did not).

i shouldn't have to search high and low through these threads in the hopes that i'm going to find the exact answer to my exact question. the truth is i don't have that much time and energy. it's a lot easier just to post

It has been established that eh going rate for acoustics professionals on theis board is 120$/hr. Your choice: do some search yourself and ask informed questions and you will get help many times over; fight tooth and nail with people ont eh acoustics forums (your reputation has already been established by you); or pay for the services.

There are several suggestions/tips/directions for beefing up mass and sound isolation on thsi forum. Do a search.

Andre

[cadesignr]

Hey duxsmer, we all know Andre is overwhelmed with paid acoustical consulting jobs. But "I" ain"t So here goes. Of course, I'm not an expert. But I can suggest something here. I don't quite understand if there is existing drywall on the other side of the studs that support this 1/4 ply. If there is AND you plan on building another wall within this space, this is what I would do to beef up that exterior leaf. I'd remove the interior drywall if existing. This will eliminate a double airgap. Then I would nail battens on the exterior over the ply joints. Caulk them also.
Then, I would glue(spray on 3m adhesive) one layer of greenboard drywall to the INSIDE face of the ply between the joists. The spray on type should keep from forming airpockets like construction adhesive beads might.(subject to code and member concensus maybe) Then caulk all perimeter and edge joints. Then, CLEAT another layer over the first. This means 1x1 boards screwed/nailed to the joists to hold this layer in place. Run a bead of caulk on the drywall or cleat prior to fastening. See my plan section. Now, I don't know how you would put a vapor baririer or where if needed. May on the studs on the interior leaf prior to putting up drywall, but someone may chime in on this. Also, this is only a NON EXPERT .02 so some of the experts may disagree. AND, there are other caveats, such as the roof leaf, ceiling leaf, etc. They need to be delt with for the same TL. AND this doesn't directly tell you anyathing in regards to LOW FREQUENCY TL. either. When you start dealing with a specific low frequency target, the problems increase exponentially. I'll quit while I'm ahead though.
fitZ

[knightfly]

Dux, you think YOU have little time? Try helping people who won't give you SQUAT for information, just want answers with no effort. The reason I directed you to that link was so you could give us enough information (including a basic location) for people to be ABLE to help you.

This is a two-way street; please be mature enough to realize there are a lot more ASKERS than ANSWERERS, that we give our time here FREE, and that we are not PSYCHIC. I personally average between 4 and 5 hours sleep a night so I can moderate this site and still get SOME of my OWN work done, so I don't need someone telling me that I'M THE ONE who needs to GIVE more. When YOU contribute over $120,000 a YEAR of your time to help others, I'll consider feeling like I OWE you answers without effort.

I didn't post that link because I considered you a "newbie", I posted it because if you READ that link already, you IGNORED 70% of the points I asked for in it.

If you were just having a bad day, we can start over; if, however, this is your NORMAL persona, then goodbye... Steve