Question about soundproofing

[Brahmall]

Alright, I'm new here, it's my first post and all, but I have a question about soundproofing a door.

My studio is set up in a spare room of the house that has a large walk in closet which is going to act as a vocal booth/isolation booth. The closet is quite large which is why I decided to use it this way, fits 3 or 4 vocalists easily.

My question is not really about soundproofing the walls since I've pretty much got that covered, the problem is that I have no room to put in a window so I was hoping to get away with a full size glass door instead. Is there anyway to sound proof or treat a door like that?

My idea was adding on an slightly angled piece of plexiglass on both sides of the door just to redirect some of the reflections, and trap some air in between the sheets of plexi and the original window. I'm not sure if any of this would work, but I would love to hear some opinions and or suggestions.

 

[chronicle]

so I was hoping to get away with a full size glass door instead. Is there anyway to sound proof or treat a door like that?

No. First off..don't confuse "treat" with "soundproof"

Hello Bramall and welcome to the forum.

My idea was adding on an slightly angled piece of plexiglass on both sides of the door just to redirect some of the reflections, and trap some air in between the sheets of plexi and the original window. I'm not sure if any of this would work, but I would love to hear some opinions and or suggestions.

Ok. You asked, you will receive. Here is the truth. Isolation is not inherently intuitive. Common sense solutions rareily work because it is NOT intuitive. First off..there is NO SUCH THING as "soundproof". You can build an isolation envelope which you can't hear a full blast 100w Marshall amp in an adjacent room...but put a Space shuttle in there...and guess what? I think you might get my drift. The key word here is RELATIVE.

Here's the real deal. It's called TRANSMISSION LOSS. Isolation assemblies are RATED by how much sound, measured in db, that is transmitted through a building assembly from one side to the other, and is rated by a Testing Lab. And the main physical means by which an assembly impedes transmission is by MASS. And depending on their function..DE-COUPLED MASS.

Furthermore, there is something called the WEAK LINK syndrome at play as well. In your case, there are many things at play. First off, your description of your walls Transmission loss is a misnomer.

My question is not really about soundproofing the walls since I've pretty much got that covered,

What does that mean? Have you measured it with a SPL meter? Until you know the facts..you don't know anything. And here's why. WEAK LINK. Unless you know the transmission loss from your "booth" into the adjacent space, you have no way of knowing what you have to build to MEET the wall transmission loss. Let me put it this way. Why would you build a door, with glass, which was 20db better than your wall? That doesn't even take the ceiling, and floor into consideration as flanking paths.

Consider this as well. Even if your "wall assemblies" were sheathed with Two layers of 5/8"drywall on both sides, this is roughly a normal HR iso assembly. To match the TL of the walls, the door glass would have to be two panes...one 3/4" thick, one 1/2" thick. So you build this door assembly..with all the given associated components such as staggered jamb/stops, seals, floating threshold, putty packed latch assembly etc etc etc. And then you fire up a 100w amp...and guess what. It didn't do a damn thing. BECAUSE..the FLOOR is a wood membrane assembly common to both rooms, and the ceiling is only one layer of drywall...with the attic common to both rooms as well....NOT TO MENTION...the HVAC ducting connects to both rooms via one duct!!

Well, that may in fact NOT be your scenario. However, that is the problem. No one knows what, how, where or anything else about your space except...

I've pretty much got that covered,

In fact..you do not. That's why we really can't tell you anything. Sorry. But that's the ugly truth. Perhaps if you tell us more..we may be able to offer some advice. Until then...good luck.

 

[Ted White]

It's common some forums to insist that a background test be done first to analyze the problem, and indeed in a perfect world that would be true. However after 13 years I have found that no one does this. So we recommend to simply plan for the worst and aim our efforts on LF isolation. If we deal with the LF, then we've also dealt with the mid and upper freqs.

Per Chronicle's great post, if you want to build and not look back, you might consider the following:

2x4 framed wall and ceiling. Decoupled with clips and channels. Insulated with standard R13 fiberglass. Two sheets of 5/8" drywall on the inside with a damping compound between them. Single sheet of 5/8" drywall outside.

If the floor is a slab, leave it alone and simply seal to it. If you have a wood subfloor, you'll want to treat the floor as well.

I'd avoid ventilation in the room, as the vent openings simply allow sund to escape. Instead just open the door on ocassion.

Lastly, use a solid core door and look at some aftermarket acoustic seals.

 

[rayc]

Vocal booths aren't really as flash as they seem to be. That's more about isolation from spill in a multiplayer take.