John Sayers' Recording Studio Design Forum

Greetings,

After a year of trying to learn as much as possible and much from this forum the time has almost come to build (well I have already started running sewer, water and electrical out) my recording studio in my detached 400 sq ft garage. I'll try to keep my plans as detailed yet brief as possible:

My main focus is to have a great mixing/overdub room so I wanted to make one room as big as possible while still having an airlock, a bathroom and a small iso. I also have the goal of making this room lively and vibey enough to get some good drum sounds in. I've believe I've settle on my plans and I've attached them here in a pdf with one hold up that I'll get to in a second. I welcome all feedback, criticism, suggestions, etc.

Construction will be double wall with an inch air gap. Beefed up outer shell with drywall cut into the stud bays and two layers of 5/8ths drywall with green glue on the inside walls. I think I've settled on just having mechanical ventilation used with portable AC and heat.

My question is regarding the ceiling. I've gone round and round in my brain and talking to people and reading and I still haven't settled on a plan. I'd basically like to dry wall the bottom side of the trusses and then frame in a ceiling under that but I don't want to lose the ceiling height. Right now my trusses are vaulted and the height is 8' 3" at the edge and 10' 4" in the center. If I double drywall the underside of the trusses leave a 1/2 air gap (maybe not enough?) and then use 2x6's (maybe not strong enough) with double 5/8's for the ceiling my height drops to a range from 7' 6 1/2" - 9' 7 1/2" which is ok but seems to waste the effort I put into vaulting the trusses. The length of the room would be more or less 17' 6"

I've attached a few pictures of the trusses. Can anyone suggest a different way to do this where I might save some ceiling height?

Thanks a bunch,
Eric

Hi Eric, and welcome!

That would make a three-leaf ceiling: It would REDUCE isolation for low frequencies, and you did mention drums, so that's probably not a good idea. Is there a reason why you don't want to go with normal 2-leaf design?

are you SURE you mean that the "air gap" will be one inch? That's really hard to do: you'd have to build both walls inside out to do that! I think you mean that you will have a one inch gap between the FRAMES, meaning that you will have about 8" of air gap (assuming that you are using 2x4 framing). Is that what you are planning? In other words, in addition to the framing visible on the photos that you just posted, you will be building a new set of framing about an inch away from that, then attaching your drywall to that. Is that the plan?

If you were to go the normal 2-leaf route, using either RC or RSIC clips plus hat channel, with your two layers of 5/8" drywall on that, you'd only lose about 2" of room height, give or take. So your ceiling height would be about 8'1" at the edges, 10'3" in the middle.

It would be a lot easier to understand if you were to put that into SketchUp, and post the SKP file here!

The basic concept looks reasonable, but I don't understand your isolation plan at all. In some places you seem to have proper fully decoupled double-framed 2-leaf MSM walls, but then they are coupled together at other places, and in yet other places there are ordinary single-framed walls. That's why it would be much easier to understand in SketchUp.

Also, the rear wall of the control room is in a concave "V" shape, with two panels angled out to the sides. It would be better to just keep that wall flat.

What is the purpose of the tiny little "box" with double doors on it, down in the bottom right? Is that just a closet for storage?

Now, after seeing this I'm thinking that the gabled ceiling plan is not a good idea, since the ceiling will not be symmetrical with the room, and symmetry is critical for the control room. So it would be better to just use a flat ceiling, all the way across. So I'd suggest leaving the roof and trusses as they are, and set new joists on top of your still-to-be-built inner-leaf wall frames, with the drywall hanging from that. It's a pity that you won't be able to use the extra height, but I don't see any other way of fixing the issue with room symmetry. If you straighten out the control room and move it to the center of the building then you could use the full height, but there would no longer be enough room on the sides for the other rooms. (Unless you also shrink the CR a bit).

That's my US$ 0.02, for what it's worth!


- Stuart -

_________________
I want this studio to amaze people. "That'll do" doesn't amaze people.

Thanks Stuart!

Well this is an area I'm still not clear on: How is it still a two leaf design with gaping holes in the form of soffit and gable vents between the two leaves?

Yes, sorry I meant an inch gap between framing.

Sorry! My friend made them and sent me the pdf I can't import them into sketchup as is. I'll see if can get the original file from him.

I know it looks confusing. There are a couple of instances where he "extended" the inner wall to the outer framing so that I could get measurements. The inner walls never actually connect with the outer walls. The entry-way/airlock has single framed walls because I was not planning on building super doors just using the "double doors" on each side of the airlock for proper isolation. The walls that separate the main room from the iso, bathroom and entry way are staggered stud 2x6 walls to save some space.

Can you elaborate on this?

Yes.

I was planning on framing the inner ceiling squared to the axis of the main room to maintain symmetry, that is to say the peak would be rotated with respect to the outer shell's peak. I also had a thought about shimming the trusses so that the ceiling hung off of the trusses would be squared in a similar manner and then be able to use RC but that might be too complicated.

[/quote] Worth a ton! Keep it coming!

Eric

A leaf is just a massive surface next to an air gap, followed by another massive surface. It doesn't have to be sealed around the edges in order to be a leaf. It might not be as efficient, but it will still be a leaf. As long as the surface is reasonably massive, and there is an air gap between it and another surface, then it is a leaf.

I'd suggest that you re-do all of that clearly, preferably in SketchUp, so we can check it over and make sure there are no flanking paths. Joining double-stud walls, single-stud walls and staggered-stud walls is a bit complicated, especially where they all meet the ceiling(s) and floor(s).

Right now your rear wall is split down the middle, vertically, and the two halves (left half and right half) are angled inwards at the edges. In other words, the center line where they join each other is further back then where they join their respective side walls. So that is a concave shape, and tends to reflect and possibly even focus sound back towards your head. That's not good. Even in the best case, it is forcing reflections to cross the room that otherwise would have stayed on the same side. It would be better to either leave that wall going straight across, unbroken, flat, from the left side-wall to the right side-wall. Another option is to turn the "V" shape the other way: Bring the apex into the room, so it is closer to the front, instead of further away.


- Stuart -

_________________
I want this studio to amaze people. "That'll do" doesn't amaze people.

Ok I understand to problem with the back wall. I still think I can vault the ceiling and keep it symmetrical but I think I should make a new design in sketchup and start a new thread in "Studio Design".

So focusing on the ceiling plan: are you basically saying don't worry about the attic venting holes and just either frame a separate ceiling with two layers of 5/8ths or hang 2 x 5/8ths off of RC or the like on the rafters? "Leaving" those holes with only one leaf of mass between them and the inside of my studio makes me nervous.

Thanks,
Eric

Hmmmmm.... Unfortunately, it looks like you have one of those situations where it is "dammed if you don't, and dammed if you do"!

Let me explain:

I'm guessing that there is also a ridge vent up top there somewhere, so those holes visible in the pictures are part of your roof ventilation system, and have to be there: you cannot block them, or you'll end up with some major and ugly roof problems down the line. So you are stuck with them, and adding a new leaf below that will, indeed, create a two-leaf system. However, it also leaves your air gap open to the outside world, so even though it is a two leaf system, it won't isolate very well. Which implies that you really do need to have a 3-leaf system. But 3-leaf systems are lousy at isolating low frequencies (read: drums, bass, keyboards...). Rock and a hard place.

Sometimes you have no choice (like here) and have to go with a 3-leaf system. But that means you have to compensate for the reduced isolation of low frequencies. The way you do that is with more mass and larger air gaps. Theoretically, you get better results if you put more mass on the middle leaf, and the optimum best plan is: "M - 2M - M". Meaning that that you have as much mass on the middle leaf as on the other two combined. That might not be possible, due to space or structural issues, but if you can do it, then that would be the best possible case.

So that's kind of the situation you are in: 3-leaf is not ideal. but 2-leaf is not going to isolate well, so 3-leaf is probably your best bet after all.


- Stuart -

_________________
I want this studio to amaze people. "That'll do" doesn't amaze people.