The No.1 Website for Pro Audio
Getting natural light in to soundproofed area?
Old 4 weeks ago
  #1
Here for the gear
 

Getting natural light in to soundproofed area?

New to the forum, but it seems like this is where the knowledgeable people are. I'm starting my project to build a drum practice (and eventual lightweight recording) space. My most pressing consideration is keeping the sound in, so I can practice at will without bothering family or neighbors. The space I have to start from is 10'x10'x8.5', finished with drywall and insulated all around.

My basic plan is to follow the standard formula of building an isolated room inside this room that does not touch except on the floor, which is concrete slab. Two layers of drywall with green glue and rockwool insulation in the new wall (I'm open to criticisms of this).

Currently, the room has a window, and having natural light is great. My question is, is there any way some light can be retained without badly compromising the sound isolation? I'm imagining things like an outer double pane window, plus an extra inner one on the main structure, plus another one, possibly smaller, on the inner wall. Any hope of the sound staying in? Is there a standard approach that is known to work?

Oh, one additional question. Regarding the ceiling, the contractor is concerned about the weight of drywall on a freestanding ceiling and would like to tie into the existing rafters with flexible hangers of some kind to prevent sagging. Should I be concerned about transmitting sound out via that path?
Old 4 weeks ago
  #2
Lives for gear
 
NF Audio's Avatar
You can absolutely let natural light into your acoustically isolated space, but as always your isolation is only as good as your weakest point.

I'd start by making sure the existing window is as well sealed as possible when you start building the new walls as you won't be able to access that window again.

You can get very thick laminated glass very affordably now thanks to the rise in environmentally friendly construction. In my vocal booth that has a window to the outside world I opted for two panes of 30mm laminated glass separated by about 3 inches of air gap and it has worked really really well. I think a similar system in your application would easily be comparable to the plasterboard construction of the rest of your room if not better, thus mostly negating your window as a weak point.

Make sure your contractors (if it's not you building) seal it up perfectly. Even minor errors around the window resulting in any kind of air gap can drastically reduce the performance. There are great window designs floating around all over, go do a little digging
Old 4 weeks ago
  #3
Lives for gear
 
Starlight's Avatar
 

Quote:
Originally Posted by Mastiff View Post
... a window ... an outer double pane window, plus an extra inner one on the main structure, plus another one, possibly smaller, on the inner wall.
That sounds like you are planning 4 layers of glass. That will not be the most effective route. Better than me explaining, read it straight from a pro's typing: look at the last question in this post about triple glazing.

Quote:
Originally Posted by Mastiff View Post
... the contractor ... would like to tie into the existing rafters with flexible hangers of some kind ...
To ensure that the hangars do not become a flanking path they need to be isolation hangars. Whoever designed the ceiling will have calculated how heavy the ceiling will be, how many hangars are necessary and how much weight each hangar has to carry so that you get hangars that are right for the job.
Old 4 weeks ago
  #4
Lives for gear
 
Jason Foi's Avatar
 

First, figure out your isolation requirements. How loud are you/can you be and at what frequencies. You didnt state it so i'll add that you need to remove the existing drywall to avoid a 3 leaf system. Hvac is a real tricky one that needs addressed before you start building.

Read up on isolation and how to calculate your requirements here:
https://www.google.com/url?q=http://...fQgkCyM6Ca1s8j

A bit on windows here:
How to install acoustic window in a two leaf wall?
Old 4 weeks ago
  #5
Lives for gear
 

Quote:
Originally Posted by Jason Foi View Post
First, figure out your isolation requirements. How loud are you/can you be and at what frequencies. You didnt state it so i'll add that you need to remove the existing drywall to avoid a 3 leaf system. Hvac is a real tricky one that needs addressed before you start building.

Read up on isolation and how to calculate your requirements here:
https://www.google.com/url?q=http://...fQgkCyM6Ca1s8j

A bit on windows here:
How to install acoustic window in a two leaf wall?
this is about (isolating) drums so we're talking peak levels north of 120dBC...
Old 4 weeks ago
  #6
Here for the gear
 

Quote:
Originally Posted by Jason Foi View Post
First, figure out your isolation requirements. How loud are you/can you be and at what frequencies. You didnt state it so i'll add that you need to remove the existing drywall to avoid a 3 leaf system.
This is an interesting thing that I had never heard of, and is very unintuitive to me. It's really better to have just one (doubled up green glued) sheet of drywall, then an open space and then the outside sheeting of the building? The sheeting is flimsy stuff, lightweight fiber board really.

Incidentally, here's the site I just read:

https://www.soundproofingcompany.com...le-leaf-effect
Old 4 weeks ago
  #7
Lives for gear
 
Jason Foi's Avatar
 

Quote:
Originally Posted by Mastiff View Post
This is an interesting thing that I had never heard of, and is very unintuitive to me. It's really better to have just one (doubled up green glued) sheet of drywall, then an open space and then the outside sheeting of the building? The sheeting is flimsy stuff, lightweight fiber board really.

Incidentally, here's the site I just read:

https://www.soundproofingcompany.com...le-leaf-effect
You'll have to beef up your outer leaf then, but whats important is maintaining a fully decoupled 2 leaf MSM system. This provides the higest ammount of isolation. The inner leaf and outer leaf should both have similar mass (lots of mass in your case). This all must be 100% airtight, so you have to add in at a minimum a ventillation system. For ventillation to not ruin your isolation, you need hvac silencer boxes.

You need to tune your wall system to around 10hz and figure out how much mass is required to acheive your desired transmission loss (TL).

As deedee said, drums are aroud 120db with tons of low end, and depending on where you live, noise ordinences could limit you to 50db or lower at the property line. This would mean you need 70db of TL at low frequencies. Thats no easy feat.

You have lots to learn if you are going to do this right, and its very expensive to get wrong. You might want to considering hiring someone to design this or spend a while researching whats needed. Rod Gervais book is a good starting point if you plan to take this on yourself.
Old 4 weeks ago
  #8
Here for the gear
 

Quote:
You have lots to learn if you are going to do this right, and its very expensive to get wrong. You might want to considering hiring someone to design this or spend a while researching whats needed. Rod Gervais book is a good starting point if you plan to take this on yourself.
Indeed, I have a lot to learn.

I'm having a hard time envisioning a practical solution to beefing up an exterior wall though. It seems unrealistic to tear off the siding on one section of the structure and put mismatched/thicker sheeting up. And whatever it is would need to be weather proof as it is on the exterior.

I'd gladly hire an expert to design this for me, any suggestions on finding someone? I have been unsuccessful finding anyone locally.
Old 4 weeks ago
  #9
Lives for gear
 
Jason Foi's Avatar
 

Quote:
Originally Posted by Mastiff View Post
Indeed, I have a lot to learn.

I'm having a hard time envisioning a practical solution to beefing up an exterior wall though. It seems unrealistic to tear off the siding on one section of the structure and put mismatched/thicker sheeting up. And whatever it is would need to be weather proof as it is on the exterior.

I'd gladly hire an expert to design this for me, any suggestions on finding someone? I have been unsuccessful finding anyone locally.
You add mass to the inside, between the studs, it doesnt have to change appearance.

Theres a list of designers at the top of the forum, they dont have to be in your area. Its not uncommon to have a project designed remotely, especially for small projects.
Old 4 weeks ago
  #10
Lives for gear
Quote:
Originally Posted by Mastiff View Post
My basic plan is to follow the standard formula of building an isolated room inside this room that does not touch except on the floor, which is concrete slab. Two layers of drywall with green glue and rockwool insulation in the new wall (I'm open to criticisms of this).
Just to be sure here, that needs to be "new wall and ceiling". No point in doing it if you don't have new inner framing and drywall for the ceiling as well.

Edit, just saw the rest of it

Oh, one additional question. Regarding the ceiling, the contractor is concerned about the weight of drywall on a freestanding ceiling and would like to tie into the existing rafters with flexible hangers of some kind to prevent sagging. Should I be concerned about transmitting sound out via that path?

Yes you should be concerned about this. Figuring a 9' span, you should be OK with 2x6 or 2x8's. There are isolation hangers and sway braces etc out there, but it would be tricky to load these correctly in this application. I'd guess with dead load only here you should be fine with 2x6's 16 oc and some bracing.
Old 4 weeks ago
  #11
Here for the gear
 

If I make the rafters of 2x6, then I start to eat up my ceiling height, so that's the trade-off I guess. 2x4's could keep the ceiling at 8' or more, but may require hangers and compromise the isolation. I have no intuition about the acoustic properties of a thin, flexible material, but under tension.
Old 4 weeks ago
  #12
Lives for gear
Quote:
Originally Posted by Mastiff View Post
I have no intuition about the acoustic properties of a thin, flexible material, but under tension.
Governed by the mass-spring law. Like a guitar string.

For isolation purposes you would want the resonant frequency of the spring to be more than 1 octave below the lowest frequency you're trying to isolate. So for 20hz, somewhere like 7hz.

That's where it gets tricky, the hanger has to be loaded correctly. Not impossible though.

OTOH, you're looking for hangers along these lines-

https://www.globalindustrial.com/p/f...yABEgKwBvD_BwE

Which will eat up some space as well.

What is your roof construction? You may actually be better off removing the existing drywall (ceiling and walls). If you orient the new joists the same as the existing, you can space the new ones between the existing.
Old 4 weeks ago
  #13
Here for the gear
 

Quote:
Originally Posted by RyanC View Post
What is your roof construction? You may actually be better off removing the existing drywall (ceiling and walls). If you orient the new joists the same as the existing, you can space the new ones between the existing.
The ceiling is drywall with denim insulation above. It's a traditional A-frame attic type situation. If the drywall is removed you could see the underside of the roof, and a certain amount of daylight from the soffits and such. It's hard for me to envision a way to not have drywall where it is on the ceiling.
Old 4 weeks ago
  #14
Here for the gear
 

Quote:
Originally Posted by NF Audio View Post
You can get very thick laminated glass very affordably now thanks to the rise in environmentally friendly construction. In my vocal booth that has a window to the outside world I opted for two panes of 30mm laminated glass separated by about 3 inches of air gap and it has worked really really well. I think a similar system in your application would easily be comparable to the plasterboard construction of the rest of your room if not better, thus mostly negating your window as a weak point.
Returning to the window... do you mean one pain on the inside room and one on the outside room? The glass on the inside room would be taking the place of two sheets of drywall with green glue plus insulation. Wouldn't it be a weak link?
Old 4 weeks ago
  #15
Lives for gear
 
avare's Avatar
 

Quote:
Originally Posted by Mastiff View Post
Returning to the window... do you mean one pain on the inside room and one on the outside room? The glass on the inside room would be taking the place of two sheets of drywall with green glue plus insulation. Wouldn't it be a weak link?
No. The glass is sized appropriately. Easy part is using .060" laminate which is doing CLD!

Last edited by avare; 4 weeks ago at 07:57 PM..
Old 4 weeks ago
  #16
Lives for gear
 

Adding to what Andre said: Glass is around twice as dense as drywall, so a pane of glass half the thickness of your drywall has the same surface density. Thus, if the total thickness of your drywall is, for example, 1 1/4" (32mm), then a pane of laminated glass 5/8" thick (16mm) would have roughly the same surface density.

And the PVB interlayer that bonds the laminated glass together, is similar to the Green Glue, in that both act as CLD's (Actually I seem to be repeating what Andre said... not adding to it!) CLD means "Constrained Layer Damping". That's what Green glue is to drywall, and what the PVB interlayer is to glass.

The first image below might help illustrate the difference between ordinary glass, and laminated glass. The second one shows the difference between "standard" laminated glass (typical PVB), and laminate glass made with a special acoustic interlayer.

- Stuart -
Attached Thumbnails
Getting natural light in to soundproofed area?-coincidence-normal-glass-vs-laminated-glass-cut.gif   Getting natural light in to soundproofed area?-laminated-glass-coincidence-dip-acoustic-pvb-vs-normal.jpg  
Old 4 weeks ago
  #17
Here for the gear
 

Thanks for the clarification. Any suggestions where to source thick, laminated glass?
Old 4 weeks ago
  #18
Lives for gear
 
Starlight's Avatar
 

Surely it cannot be that difficult to look up a few local glass suppliers? How about: Vista Glass, Columbus Glass & Screen or Hartman Glass for example?
Old 4 weeks ago
  #19
Here for the gear
 

Quote:
Originally Posted by Starlight View Post
Surely it cannot be that difficult to look up a few local glass suppliers? How about: Vista Glass, Columbus Glass & Screen or Hartman Glass for example?
Got it. I didn't realize any standard "thick, laminated" glass would do the trick (vs. specialized acoustic stuff). Thanks.
Old 4 weeks ago
  #20
Lives for gear
 
avare's Avatar
 

Acoustic interlayer material is not exotic. You just have to order it.
Old 3 weeks ago
  #21
Here for the gear
 

Next topic is doors. Is it worth it to buy fancy IAC doors vs. just getting heavy solid core doors and sealing them well? I've so far been unsuccessful in even getting them to tell me a price or lead time. Found one unhappy customer on the forum here, but that was 5 years ago or so.
Old 3 weeks ago
  #22
Lives for gear
 
Starlight's Avatar
 

You have already had input from Soundman2020. On his web site he shows how to make doors, here.

Alternatively, John Brandt has a PDF of plans for studio doors, second last link on this page.
Old 3 weeks ago
  #23
Lives for gear
 
avare's Avatar
 

Quote:
Originally Posted by Starlight View Post
You have already had input from Soundman2020. On his web site he shows how to make doors, here.

Alternatively, John Brandt has a PDF of plans for studio doors, second last link on this page.
+1 and Rod has plans in his book. Make them at least 36" wide.
Old 3 weeks ago
  #24
Here for the gear
 

Quote:
Originally Posted by avare View Post
+1 and Rod has plans in his book. Make them at least 36" wide.
Why so wide?
Old 3 weeks ago
  #25
Lives for gear
 
avare's Avatar
 

Quote:
Originally Posted by Mastiff View Post
Why so wide?
You can do what you want.
Old 3 weeks ago
  #26
Here for the gear
 

Quote:
Originally Posted by avare View Post
You can do what you want.
I'm just asking. Is it for acoustic reasons? I need to understand the trade-offs, since the sweep of a huge door will eat up space in the room.
Old 3 weeks ago
  #27
Lives for gear
 
avare's Avatar
 

Quote:
Originally Posted by Mastiff View Post
I'm just asking. Is it for acoustic reasons? I need to understand the trade-offs, since the sweep of a huge door will eat up space in the room.
Access. Like I just wrote, you can do what you like.
Old 3 weeks ago
  #28
Lives for gear
 
Jason Foi's Avatar
 

Quote:
Originally Posted by Mastiff View Post
Why so wide?
If you're a commercial facility in the US, ADA requires 32-48", but also, its easier to bring gear in a larger opening, especially if access is thru a hallway.
Old 3 weeks ago
  #29
Lives for gear
 
avare's Avatar
 

Quote:
Originally Posted by Jason Foi View Post
If you're a commercial facility in the US, ADA requires 32-48", but also, its easier to bring gear in a larger opening, especially if access is thru a hallway.
The next smaller width is 32". The 3 largest tympani will not fit. That is just one off the top of my head.
Old 3 weeks ago
  #30
Lives for gear
 
avare's Avatar
 

Quote:
Originally Posted by Mastiff View Post
Next topic is doors. Is it worth it to buy fancy IAC doors vs. just getting heavy solid core doors and sealing them well? I've so far been unsuccessful in even getting them to tell me a price or lead time. Found one unhappy customer on the forum here, but that was 5 years ago or so.
Isostore advertises IsoDoor SD for $2,150 in the "standard" size of 36"x80".

https://isostore.com/product-catalog...rol-doors.html
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Forum Jump
Forum Jump