Need some advice on soundproofing and acoustic treatment of my tiny studio

[noiseformoney]

Hi all!

I am in the process of treating my tiny post production studio at work.
The room is nearly a perfect cube, with the dimensions W:273 L:299,5 H:276 cm.

At the moment the room has a mastering suite on the right side and a video edit room on the right. I can hear people talking through the walls, and yeah, when they are doing any work, I am pretty annoyed, e.

So, I am planning to noise insulate and do some acoustic treatment.
I´ve read a hole lot on this forum and stolen some ideas from here and there, and ended up with a SketchUp model.

The studio is used for post audio editing and mixing of a TV soap.

It would be great to get some feedback from you guys!

Image Explanation:
The white outer walls are the old, current walls. I am planning on letting these stay the way they are, as I cant interrupt the work going on in the suites on each side.
These walls are pretty basic, made up of studs and a single layer of drywall on each side, and yes, they doesn't block much sound.

The next layer is studs placed 1 cm away from the old wall, so it will be decoupled. It has one layer of asphalt sheets, two layers of drywall (15 mm), filled with 5cm rockwool.

The next layer is made up of 48mm studs (98mm in front), gradually getting wider towards the back. The ceiling will also get higher towards the back, as you see on the sketch. I will fill the walls/ceiling with 50mm acoustic panels (100mm in the front wall), and cover them with a breathing material to make it all nice to look at.

In the back, behind the last wall, I have planned to make a basstrap, made up of 50mm studs, filled with acoustic panels. There are two layers of these, 10 cm apart.

Okay then, I guess you get the idea


I hope for some good constructive ideas and hints back

Thanks!

[jimcroisdale]

Size wise, it's alot like my little room.

You're gonna need some fresh air in there, cos it'll get mighty stuffy - especially if you've eaten any curries recently....

Looks cool though!

Jim

[noiseformoney]

Thanks for replying

I can see that my plan is pretty hardcore compared to the
basstaps you made for your room, so I'm wondering, am I going too far?

Anyone with experience covering a small room like i am planning?

Haha, yeah, I love the curry, so I am planning on moving the ac unit that's already
in the room to the back, just over the door
I am thinking about making some kind of noise trap for this aswell, but still trying to
find some good solutions.

[jhbrandt]

Originally Posted by noiseformoney

I am in the process of treating my tiny post production studio at work.
The room is nearly a perfect cube, with the dimensions W:273 L:299,5 H:276 cm.

ok that IS tiny... only 22 cubic meters. ALMOST a cube.. but, luckily, not quite. You will have modal issues - but you probably already knew that. Right around 100 Hz.

Originally Posted by noiseformoney

The studio is used for post audio editing and mixing of a TV soap.

Are you doing surround mixing?? 5.1?? etc.

Originally Posted by noiseformoney

The next layer is studs placed 1 cm away from the old wall... one layer of asphalt sheets... two layers of drywall ...rockwool...48mm studs (98mm in front), gradually getting wider towards the back.... The ceiling will also get higher towards the back, as you see on the sketch. I will fill the walls/ceiling with 50mm acoustic panels...
In the back, behind the last wall, I have planned to make a basstrap, made up of 50mm studs, filled with acoustic panels. There are two layers of these, 10 cm apart.

Well, first of all: You are wasting space and material with all that and not building an effective soundproof partition.

Give yourself some room in there.. it's tiny.. don't make it too much smaller.

1. Use steel studs. They are much better with transmission loss than wood.
2. Place your bottom plate leaving at least a 4" air space from the existing wall. -- this is what really does the isolation.
3. Rock wool between the steel studs.
4. 2 layers of 5/8" gypsum board sandwiched together with Green Glue.
5. You will need to install another door on the inside wall.

**** Do not Connect the new wall to the old ones. ANYWHERE ****

An exterior type residential door would be fine for this, but you must get the entire door & frame with weather seals as a unit.

With this suggested wall you could get an STC rating of 56 on all walls. Make sure that it is not compromised by the ceiling. - the same rockwool + double layer 5/8" drywall with Green Glue applies there too. Your ceiling joists are attached to your new wall only.

Room Treatment:

Well to start off let me quote Ethan Winer:

Originally Posted by Ethan Winer

Here's my standard reply which will get you 99 percent of the way there. All rooms need:

* Broadband (not tuned) bass traps straddling as many corners as you can manage, including the wall-ceiling corners. More bass traps on the rear wall behind helps even further. You simply cannot have too much bass trapping. Real bass trapping, that is - thin foam and thin fiberglass don't work to a low enough frequency.

* Mid/high frequency absorption at the first reflection points on the side walls and ceiling.

* Some additional amount of mid/high absorption and/or diffusion on any large areas of bare parallel surfaces, such as opposing walls or the ceiling if the floor is reflective. Diffusion on the rear wall behind you is also useful in larger rooms.

For the complete story see my Acoustics FAQ.

There's a lot of additional non-sales technical information on my company's web site - articles, videos, test tones and other downloads, and much more.

--Ethan

There's more on the GIK site too. -- and mine JavAkustik

Basically, you will need to put some good bass traps in every corner, good broadband absorbers at all reflection points, eliminate flutter by checker-boarding absorbers on walls and ceiling so that opposing surfaces are not both reflective.

NOTE: If the ceiling is dropped, look up there - and check that the existing walls go all the way to the next floor or roof. IF THEY DO NOT - You must extend them to the roof or next floor (and seal them well), otherwise all your efforts to sound proof will be wasted.

good luck,
Cheers!

[noiseformoney]

Thanks a lot for your answer!!
This was the constructive feedback I was looking for!

Originally Posted by jhbrandt

ok that IS tiny... only 22 cubic meters. ALMOST a cube.. but, luckily, not quite. You will have modal issues - but you probably already knew that. Right around 100 Hz.

Yeah, 100Hz up to around 500 Hz is pretty terrible at the moment.
The only type of "absorption I got in the room now, is molton on the walls, .

Are you doing surround mixing?? 5.1?? etc.

Luckily I am not doing any surround at the moment.
The producers have been talking about it, but I've told them that, if so, I will need a new, much bigger room, and lots of $ to treat it (and lots of gear )

Well, first of all: You are wasting space and material with all that and not building an effective soundproof partition.

Give yourself some room in there.. it's tiny.. don't make it too much smaller.

1. Use steel studs. They are much better with transmission loss than wood.
2. Place your bottom plate leaving at least a 4" air space from the existing wall. -- this is what really does the isolation.
3. Rock wool between the steel studs.
4. 2 layers of 5/8" gypsum board sandwiched together with Green Glue.
5. You will need to install another door on the inside wall.

This was sort of what I was planning to do, kind of.
I was planning on a 2" gap from the old wall, but I'll make it 4" now.
How thick should the new wall/insulation be? I was thinking of 2", but should I make that 4" too? What kind of rock wool is the most effective here?
I've read that putting a layer of asphalt-sheets between the layers of gypsum is effective. Is this true, or just a waste of money? (they are expensive).
I'll have to try to find green glue here in Norway. If anyone know, a hint would be great!

Room Treatment:

Basically, you will need to put some good bass traps in every corner, good broadband absorbers at all reflection points, eliminate flutter by checker-boarding absorbers on walls and ceiling so that opposing surfaces are not both reflective.

The production company bought (before I started working here in august) a whole bunch of Ecophon Wall Panel™ A/Texona, 40mm. The sales rep told them that covering the walls and ceiling with this would be a perfect solution. Well, looking at the sound absorption coefficient chart, the absorption drops dramaticly at 500Hz and below, so no bass trapping. Kind of makes sense with the 40mm depth.
Well, the producer will probably kill me if I don't use any of the 103 m2 they bought of this stuff (I think they are planning on using it in edit suites too).
So.. would it be an idea to cover the walls and ceiling with it, and then put bass traps in corners and on the back wall? Or, will this make the room too dead?

NOTE: If the ceiling is dropped, look up there - and check that the existing walls go all the way to the next floor or roof. IF THEY DO NOT - You must extend them to the roof or next floor (and seal them well), otherwise all your efforts to sound proof will be wasted.

The room is built as a series of rooms inside a huge studio. So the walls go up to the ceiling (of the room, not the studio hall). There are two ac ducts in the ceiling, should i seal these? We have turned this AC off for my room anyway, as it is way too noisy.

Speaking of AC. I am now using a Multi Split AC System. The fan part which is inside the room, is kind of noise (pretty much the noise of air blowing). Do anyone have tips on how to make this silent? Connecting to the house AC is possible, but it is noisy as hell. Yeah.. we have huge problems with it recording in the studios.

Thanks again John! I appreciate it!
You are making my day a whole lot better!

[jhbrandt]

Marius,

Thickness of insulation in new wall.. I'd make it 4" if possible. Using 4" steel studs... Use anything that is close in specs to the Owens-Corning 703, which does an excellent job.

As for the layer of asphalt-sheets - not worth the trouble or expense. If you want great isolation, get the Green Glue.

The production company bought (before I started working here in august) a whole bunch of Ecophon Wall Panel™ A/Texona, 40mm. The sales rep told them that covering the walls and ceiling with this would be a perfect solution. Well, looking at the sound absorption coefficient chart, the absorption drops dramaticly at 500Hz and below, so no bass trapping. Kind of makes sense with the 40mm depth.

You could probably stack these together... or mount them with about 40 or 50 mm of airspace behind them to improve the LF absorption. - yes it will be pretty dead.. but after you get past the early reflection zone you could put up some polys or something similar to brighten up the back end... i dunno - it's soooo small..

AC is a whole 'nuther thing. We can get to that after you've got your design.

[noiseformoney]

Originally Posted by jhbrandt

Thickness of insulation in new wall.. I'd make it 4" if possible. Using 4" steel studs... Use anything that is close in specs to the Owens-Corning 703, which does an excellent job.

You could probably stack these together... or mount them with about 40 or 50 mm of airspace behind them to improve the LF absorption. - yes it will be pretty dead.. but after you get past the early reflection zone you could put up some polys or something similar to brighten up the back end... i dunno - it's soooo small..

Wow, this will actually make my room a whole lot smaller than the solution I first was thinking of, e. With a 4" wall, 4" from the old wall, and then a 2" layer of absorption, 2" from the new wall.. thats 12" on all siden and the roof.. e, tiiiny

Well, i'll make a new sketchup sketch and see how it looks.

by the way, I read a whole bunch of stuff on the Rockwool site about insulation. The say that you should always use gypsum on both sides. Is this BS? Everybody here, including you, are saying gypsum on only one side..

Thanks again!

[jhbrandt]

Yes, only one side.

Sometimes these things are counter intuitive. But the research, math, experimentation, & documentation all point to these conclusions. And believe it or not, 2 walls are better than 3 or 4 even.

There are quite a few threads on this subject here, just do a search. Quite a few with diagrams and examples.

Good luck!

[noiseformoney]

Hi!

I've made a new sketchUp model after getting some advice here.
Take a look

Ok.. explanation..
New 10cm insulation wall/ceiling 5cm from the old wall (not touching).
This new wall has 10cm rockwool and two layers of gypsum with greenglue in between.

Then, 4cm Ecophon Wallpanel A raised/hung with steel frames.
This will be 5cm from the insulation wall.

Basstraps in the two back corners. This is basically a frame of the ecophon wallpanel, with rockwool from floor to ceiling on the back.

Hope for comments!

Thanks a lot