John Sayers' Recording Studio Design Forum

Little
Update
half way done beefing up all walls with extra layer of drywall
adding 2 layers of 5/8ths to middle Leaf on Monday

Can anyone comment on the inside dimensions of my build and let
me know if should make any changes
as far as modes etc

Thanks

_________________
Tom

I think I bought myself an inch or 2 for bigger air space for the ceiling like you suggest Stuart.
Would 3 inches cut it, if I can only get 2 layers of drywall on middle leaf ?

how big should the air-gap be what is your recommendation?

I got to stay with the 2" air gap around the walls though does this mess things up?

_________________
Tom

3 inches is better than 2, and 2 layers of drywall on the middle leaf is better than one! The big thing with building studios in existing spaces, is that its a juggling game of trade-offs, optimizing this at the expense of that, tweaking and adjusting to get the best overall compromise. So if 3" and 2 layers is what you can get, then that's what you can get! It will give you reasonable isolation. You could improve it more by using Green Glue in between those two layers, but that is extra expense: another trade off! Is it worth the extra expense to add a couple of points of isolation in the low end? Your call...

Simple answer? "As big as possible!" Realistic answer? As big as you can make it, within reason. The ideal wall for really good isolation would be a 2-leaf wall with three layers of 5/8 drywall on each side, with Green Glue on every layer, over a 16" inch air gap, filled with mineral wool. But that would be really hard to do, not to mention outrageously expensive, for most home studios! It would isolate very well 20 Hz on up, with around STC Seventy-something, theoretically. But not realistic at all for home studios.

OK, hard facts: For a 3-leaf system with 2 layers of 5/8" per leaf over 3" air gaps, no Green Glue, cavity filled with insulation, theoretically that will isolate from about 70 Hz upwards, and will isolate decently above 95 hz. If you could make the gaps 4", that would change to about 60 Hz and 85 Hz. Theoretically that will give you STC in the low fifties. In real-world subjective terms: Acoustic drum kit played loudly inside will be well muffled, but audible outside at around 60 dB or so, which means you could hold a conversation right outside the wall at normal levels (not having to raise your voice), without much difficulty. 30m away it would be pretty much inaudible, except maybe late at night. A normal mixing session at 85 dB inside will be as nothing more than a slight whisper outside. Normal speech will be totally inaudible. Going the other way: pretty much everything except really heavy vehicles, low-flying helicopters, loud rain and thunder will be inaudible inside (OK, add earthquakes and volcanoes to that list! ).

All of that is purely theoretical, of course: No guarantees. Your mileage may vary. Void where prohibited by law. Other usual disclaimers apply...

In other words, it is what it is. If that's what you can fit into the available space, on the available budget, then that's what it has to be. It might not be optimum, but one thing I can say for sure: it will be one hell of a lot better than what you have right now, no matter which way you look at it!


- Stuart -

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

thanks Stuart !!!!!!!!!!!!!!!!!!!!!

that makes things more clear and a little easier to sleep hehehehe
I can live with those results!

kinda fell off but ready to get rocking.


any feedback on my dimensions rooms modes etc...?

_________________
Tom

Im framing this weekend

any feedback on my dimensions rooms modes etc...?

now would be the time to frame the room into better dimensions with less mode problems

I don't mind loosing a foot or so on the length or width if its going to make things a lot better ????


help

_________________
Tom

Tom, maybe you could post your final SketchUp file, with the final plan. Since you've changed dimensions and plans along the way, I'm not really sure what your actual dimensions are any more!

- Stuart -

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

will do

give me a few days

thanks

_________________
Tom

Aloha

Wow major detour had to work a job out of town for a bit. I am back and ready.......

I attached pictures of the current updated design and I cross section for reference.
I could upload another SKB file but it would require a quite a bit of work as there
are certain issues that came up in the model +
I figured the info below should be suffice?

Here are the dimensions of the outer shell

Length 19' 5"
Width 17' 3 1/4"
Height 9' 1" (all I got to work with

(That part is probably not that important for my question but I wanted to be thorough)

Now here is the information I believe you need for feedback on the modes and if I should move a wall
or something?

Finished Inside dimensions of the room within the room .
(These calculations are from front surface of last layer of drywall, no treatment or anything has been added to the equation)

Length 18' 1"
Width 15' 11 1/4"
Height 7' 9 1/2"

My question:
Now is the time to change any of the dimensions to create better modes etc....
Can someone please give me some feedback on the rooms modes I will be dealing with and if I should change any dimensions or can I live with the inside finished dimensions that I posted above?

Also in a room this size should I angle the side walls 6 degrees on each side if I can spare the room?
Or could I just angle one wall 12 degrees to kill the flutter echo or would that mess up my stereo
imaging?

What is the minimum angle I can get away with?

Any feedback or advise is much needed at this point and will be greatly appreciated as its the final detail
and I can get busy and build this thing for real this time lol!
thanks

Tom

_________________
Tom

erased

_________________
Tom

another pic to see where I'm dreaming of going with this studio for reference

_________________
Tom

Hi again, Tom!

You seem to be misunderstanding the room dimensions and how modes / ratios work. You said that you are measuring the inner dimensions to the finish surfaces of the walls, not considering treatment, but your "cross section diagram" shows that you are measuring the 7' 9 1/2" to the lower surface of a ceiling-mounted "bass trap": That's not correct. Bass traps are treatment! Not only that, but a bass trap on the middle of the ceiling isn't all that useful anyway. The measurement should be to the drywall, the lower surface of the ceiling, what you would see when standing inside the room looking up as soon as the drywall is in place.

So please correct your dimensions to reflect ONLY the full distances between actual drywall surfaces.

Also, the same diagram shows something strange with your roof! It seems to be made of three layers of drywall, with only one layer attached to joists at the edges! Maybe you could show more details of that...

- Stuart -

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

I was aware that bass traps are treatment lol sorry goofed up.

the only thing that has changed dimension wise is the height, I just removed the 4" bass trap/air gap from the equation like I said in the first place lol
sorry I got mixed up, that was more for me to know my final ceiling height.

here are the updated dimensions and an updated pic.

Finished Inside dimensions of the room within the room .
(These calculations are from the front face of the final layer of drywall, no treatment or anything has been added to the equation this time sorry

Length 18' 1" finish drywall face to finish drywall face within the final room etc...
Width 15' 11 1/4"
Height 8' 1 1/2" (Bass-Trap - Airgap removed)

let me know if there is anything else I need to do

Thanks

Tom

_________________
Tom

The ratio isn't fantastic, and I think it could be improved a bit. The room width is almost exactly twice the room height, so the room fails one of the key three tests. The closest dimensions where the room passes all three tests, is with a width of 15' 4 3/4", meaning you would need to move each of the side walls about 3 1/4 inches in, thus losing 6.5" of width, total. I'm not sure if you want to do that, but that would get you to a better distribution of modes. The Bonello graph for that looks a lot better than for your current ratio.

Apart from that, the plan looks good. About the only other thing I'd suggest is to think about moving that rear door (between the keyboard and sofa) a bit, since that corner is where you should have a large bass trap. If you could slide that door (and the sofa) over a couple of feet, you'd have room for the bass trap there.

- Stuart -

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