Studio Build in Process

[dasnub]

Hi everyone,

I'm hoping you can all help me make a few critical decisions on my studio build that was started this week. I've decided to build on my second story instead of in the basement, both for resale value reasons as well as ceiling height and general comfort. The space will have a control room and a live room. The control room is an enclosed space with a room ratio of 1/1.28/1.54, with 8 ft ceilings, 10'3" wide and 12'4" long. The live room is, for now, open to the main living space, which has 17' ceilings. The floor joists between the live room and the control room run in opposite directions, so I'm hoping this gives me less sound transfer through the floor between the live room and control room.

They have already framed the wall between the main living room and the control room- I had them do staggered joist construction as the room dimensions did not leave enough space to do a true double wall. I will do the same construction on the wall that is shared by the live room and the control room.

Where things get tricky is this:
1. My custom build studio desk is 7'7" long and obviously needs to be centered for first reflections. The room is only 10'3" wide. This means there isn't enough space on the shared live room/control room wall to accommodate both the desk and even a basic door. As a result, I'll be putting the desk on the opposite wall- i.e. my back will be to the live room when I'm in the control room.
2. I may only live here a few years and the setup needs to be attractive enough that it makes sense to the next buyer. I also want to be able to see from the control room into the live room. That means an ugly steel door(s) is not an option. Ideally I would like a double door with glass in it, that provides isolation when closed but opens up the spaces to one another when I want that.

There appear to be very few options for the type of door I'm talking about- double doors with glass with high STC ratings. The ones that exist are very expensive. I'm not opposed to spending money on it, but understanding that a sound isolation system is only as good as its weakest link, is what I'm doing with the walls and floor going to give me enough isolation to justify what might be a $5k door? If so, I'd be curious to hear peoples' suggestions on doors that might fit what I'm looking for.

Another alternative I've considered is hanging regular old French doors that swing into the live room, with double steel doors right behind them that swing into the control room. Is this a potential viable option, and what things should I do to make sure I've got a proper seal?

I've attached a few pictures so you can see the current rough layout.



CONTROL ROOM


LIVE ROOM

[Soundman2020]

Hi "dasnub". Please read the forum rules for posting (click here). You seem to be missing a couple of things!

Also, I would strongly, STRONGLY urge you to NOT build anything at all until you have a complete, detailed, full design for your studio. Trying to build without a detailed plan is a recipe for disaster. We have seen dozens of cases like that on the forum: those who carry on building anyway, always fail. Always. Those who stop and and design properly first, usually succeed. You have already made several basic mistakes, and are making several invalid assumptions, but there is still time to take that apart and fix it, if you stop now. If you don't, then it will be too late, and your studio will fail.

Not trying to scare you: you just pointing out the realities.

Here's a few of the biggest issues:

floor joists between the live room and the control room run in opposite directions, so I'm hoping this gives me less sound transfer through the floor between the live room and control room.

Your "hope" here is ill-founded. That wont help at all. Sound does not care which way it travels through a flanking path, and one flanking path is as good as the next, regardless of orientation.

They have already framed the wall between the main living room and the control room- I had them do staggered joist construction...

What about the other walls? Isolating one single wall accomplishes nothing at all. Isolation is "all or nothing". Either you isolate all four walls, and the floor, and the ceiling, and the door, and the window, and the HVAC system, and the electrical system, all to the same level, or you do nothing at all. There is zero point in isolating only one wall.

as the room dimensions did not leave enough space to do a true double wall.

Then change the dimensions!

1. My custom build studio desk is 7'7" long and obviously needs to be centered for first reflections.

It does NOT need to be centered for first reflections, since in any properly designed studio there will not be any first reflections at the mix position! The reasons your desk must be centered is for stereo image, accurate soundstage, symmetrical sweet spot, and balanced acoustics.

"I also want to be able to see from the control room into the live room." Yet: "my back will be to the live room when I'm in the control room." That's a rather large contradiction! Why bother putting glass in between if you won't ever be able to look through it?

That means an ugly steel door(s) is not an option.

Why not? Many acoustic steel doors have windows in them. So too do many wooden acoustic doors. And also all glass acoustic doors...

Ideally I would like a double door with glass in it, that provides isolation when closed but opens up the spaces to one another when I want that.

That is, indeed, a common way of doing it. Many of John's designs use sliding glass doors between rooms.

There appear to be very few options for the type of door I'm talking about- double doors with glass with high STC ratings.

Studio isolation is not measured in STC. STC has no meaning at all for studio isolation, since it refers ONLY to part of the mid range of the audio spectrum: the part that is most prominent for speech and typical office noise. That's what STC is designed to measure. It does not even take into account the bottom two and a half octaves, nor the top two and a half octaves. STC teslls you nothing at all about how well a door will work to isolate a studio. I can build you a wall rated at STC-50 that has lousy isolation for studios, and I can build you another wall that is rated at only STC-40 but performs MUCH better for full-spectrum music isolation. Do not use STC for judging door isolation. Only ever look at the full TL curves.

is what I'm doing with the walls and floor going to give me enough isolation to justify what might be a $5k door?

No. It wouldn't even justify a $500 door. And in any event, for a studio you would need TWO such sliding glass doors, back to back, one in each leaf of the wall.

what things should I do to make sure I've got a proper seal?

Firstly, that the surface density of the door is greater than (or at the very least, equal to) the surface density of the leaf that it is in, secondly that the depth of the air cavity between the doors is at least as large as the depth of the air cavity between the leaves in the wall, preferably 1.4 times greater, and thirdly that there are at least two (preferably three) independent full-perimeter seals around each of the doors.

Of course, all of that is assuming that you first re-build your walls and floor correctly. If you don't do that, then you might as well just put in a typical $100 closet door.

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Those are just the most obvious issues that stand out from the photos, and the small amount you told us.

- Stuart -