STC rating of double glass sliding doors?

HI :) I have looked but cant seem to find ....soo... Does anyone know what the approx STC rating of running two sliding glass doors as per the SAE site, would be? I understand they must be angled and such during construction, i am just curious on their sound isolation capabilites? Thanks in advance Peter

Peter - the doors I used at left Bank had an STC of 33 each. Not sure what that makes them when added together. :wink: cheers john

thanks john Peter

34. (hehehehehehe...) Seriously, probably around STC 40-42. It would be nice if two STC 33 items made for STC 66, but alas... Steve

34. (hehehehehehe...) Seriously, probably around STC 40-42. It would be nice if two STC 33 items made for STC 66, but alas... John, a very basic imperial test would be put a ghetto blaster in the control room, SLM at the doors, crank it to 90 dB with both doors open, close one door, measure, close the other door, ditto... I did this once with a blaster and a refrigerator to see how good the magnetic seals were (I think I ended up testing the frig walls instead, worked out to 37 dB difference between door open, door closed)... Steve

Well, I can verify that 2 sliders really do the trick. We've had ours installed the last few weeks, and the work great. About the only thing they won't stop is the really low end on a bass drum. Don't get me wrong, they'll knock the bass down significantly, but you're still gonna get some transfer. As for the hi and mids, no problem.

That's good to know Oz. I'm planning the same thing for my place.

I posted this pic at HR so I might as well post it here: these are the features to look for ina sliding glass door cheers john

I have strongly been considering using John`s ideas of sliding doors between my booths and my control room. I like the potential sight lines they offer. What kind of doors are you all using? Are they standard sliding glass doors that one could get at home depot or are they super expensive acoustical doors? Any info would be great!

I have strongly been considering using John`s ideas of sliding doors between my booths and my control room. I like the potential sight lines they offer. What kind of doors are you all using? Are they standard sliding glass doors that one could get at home depot or are they super expensive acoustical doors? Any info would be great!

check your door manufacturers locally - you may find that whilst they don't carry any acoustic doors in stock they may have one in the range. The doors at left bank were exactly that and were made in Brisbane to our size specs and transported down to us (70 miles or so) cheers john

My doors got put thru the stress-today. I had a friend of mine from a local death-metal act come out and wail on the kit... while the rest of his band stood in the control room and watched me close the sliders.... They were picking thier jaws up from the floor because they couldn't belive the difference. There was some VERY minor leakage, but overall, I'm totally blown away by the isolation... and these weren't even acoustic sliders. Hell, we picked one up off of a "damaged" rack and got a $200 discount... turns out it was just missing a handle. :) I love it when things get ecenomical!

wow...so I can really get away with solid "normal" sliding doors? Life is good...especially since my drum booth is not even connected to my control room...it is on the far end of the studio. Also...the other booths that will be connected are primarily for vox, and horns/strings

I can vouch for the effectiveness of garden variety doors as well. Mine are separated by a pretty good offset air space (20 - 36 inches); but the effect is pretty stunning. Alex

to resurrect an old thread, wouldn't part of the problem be the STC rating of each individual door, not the rating of them combined? Sure if you are only trying to reduce sound transmission between recording space and control room, but if you have a room inside a room, to reduce sound transmission to neighbours, wouldn't the doors become your weakest link? ie you only need to build your walls to the same quality as your doors. If you built a wall with say, 2 layers of 16mm plasterboard and some green glue, much of this expense would be wasted as soon as you added sliding doors with an STC of 33 or similar? I am assuming this standard twin leaf design plus green glue offers at least 33 on its own. am I wrong? I can't find anywhere that can tell me the stc of 16mm plasterboard, GG, 16mm plasterboard, alone. it all has another layer, maybe with an air gap.

wouldn't part of the problem be the STC rating of each individual door, not the rating of them combined?

Not really. An MSM wall is a tuned system: change one thing and you change the entire tuning. The idea is to adjust the parameters (mass and air gap, mainly) to get the resonant frequency down to less than half of the lowest frequency that you want to isolate. If you have less mass on wall, then you need a greater distance between them to get the same resonant frequency.

wouldn't the doors become your weakest link?

Doors (and windows) are usually the weakest link, regardless of the type that you use. But the issue isn't so much mass as it is sealing. You can have a pair of hugely massive doors with a large air gap between them, but if they are not extremely well sealed then you wasted a lot of money!

ie you only need to build your walls to the same quality as your doors.

The normal approach is to start the other way around: design your walls to get the level of isolation that you need (based on your design parameters), then figure out how to get your doors and windows up to the same level of isolation as the walls. That might involve more mass in the door/window, or larger air gaps, or both, but it absolutely certainly will involved several sets of very tight seals.

If you built a wall with say, 2 layers of 16mm plasterboard and some green glue, much of this expense would be wasted as soon as you added sliding doors with an STC of 33 or similar?

Not necessarily! You would choose your doors mass (ie, glass thickness, type, density) with the correct amount of mass for the application, and also choose the air gap of the right size for that mass. An pair of back-to-back sliding doors rated at STC 33 each might well do the trick, depending on the design goals. They don't act individually in an MSM wall, but rather act together, as part of the entire tuned system.

I can't find anywhere that can tell me the stc of 16mm plasterboard, GG, 16mm plasterboard, alone.

Single leaf? Not very good. Single leaf is limited by mass law, so you are basically talking about the mass of 32mm of drywall. That would maybe get you in the high 20's or so, depending on how well it is sealed, how it is mounted, etc. Just checking here: You are aware that STC is a lousy method for judging the isolation of a wall for studio use? You should never use STC rating for studio design. - Stuart -

Does anyone know where I can get sliding glass doors that only have the door side? ..which then slide into the wall. The reason I need this instead of the traditional sliding glass door with two sections of glass is because the opening that I want them for is only about 4 feet. And since I only need one side, it seems like I could get them cheaper. Has anyone heard of such a thing? Also, what are the methods and products for adding seals to a sliding glass door if is not isolating enough based on a sealing problem?

It sounds like you are describing a pocket door, where there is only one panel that slides into the wall, instead of sliding past the other one? - Stuart -

Soundman2020 wrote:

It sounds like you are describing a pocket door, where there is only one panel that slides into the wall, instead of sliding past the other one? - Stuart -

Yeah, exactly .. Except I've never seen one where the the door is glass!