Building a sound proof room- Updates on the Lipscomb project.

[@apwells]

I’m not sure if you read comments, but I’m an acoustical consultant and a very grateful subscriber. I’ve learned a lot from your channel. So hopefully this is helpful information for you before you get too far: Make sure any outlets/boxes in your party wall are backed with moldable putty (3M or Lowry pads), the lights and speakers should also be backed with the same drywall equal to the construction of the ceiling so it doesn’t come up through the ceiling plenum. The analogy is like having a bucket with small holes in it. Last one…it sounded like you were describing a floating floor for the studio, make sure they hold the edge of the plywood off the wall an use neoprene foam tape, or 1/2” compressed fiberglass boards so the floor doesn’t bear on the walls and transfer noise through a direct physical vibration (structure borne noise). Good luck, and I’d be happy to look at your plans and details if you aren’t working with an acoustical consultant. It would be nice to repay you in a small way for all of the knowledge you’ve put out there!

[@aengeram]

In his case would the avenue of Green Glue and hat channel with isolation clips be worth it as well?

[@apwells]

@@aengeram probably not. Once you decouple the walls with the double stud the hat channel wouldn’t provide additional decoupling, and would make the wall less stiff actually allowing some sound frequencies to more efficiently move the drywall. Greenglue IMO has only one practical use: when you only have access to one side of the wall and you need to “laminate” another layer to introduce some additional mass. Most applications would still be limited by outlets and other penetrations where you’d be laminating drywall, so there are pretty limited use cases.

[@KenYamaguchi-sg5zr]

Do you think there is any merit to Rockwool and Mass Loaded Vinyl Rubber inside the dual wall staggered stud cavity? Also is there any merit to Rockwool and Mass Loaded Vinyl Rubber under a raised subfloor? Also in situations where there is a lot of airborne noise, do you see the value in adding sound absorbing panels on the interior walls? Finally, regarding airborne noises, do you see the value to hanging vertical sound baffles from the ceiling? Thanks in advance.

[@apwells]

@@KenYamaguchi-sg5zr rockwool or any sound attenuating batt is crucial, MLV in the wall could give you extra mass without increasing width or increase the insulating performance at low frequencies. This material can also be used in cases where there’s plumbing or conduit in the wall and so there noise creating in the wall or services preventing the use of insulation, to help bolster transmission loss, this would be the main reason to use it in double stud construction over an additional layer of drywall in my experience. MLV in the floor could be used to reduce noise from physical impacts if sandwiched between layers of plywood/OSB, other resilient maters (recycled rubbers, generally) could be used below the subfloor more generally for activity generated noises and movement. Sound absorbing treatment are usually used to reduce the amount of reflected sound, to improve the spaces acoustics aesthetics (listening to speech or music), for noise containment, especially with a large common partitions, you’d see little benefits baffles are best for reducing sound traveling in spaces with large dimensions relative to the ceiling height.

[@KenYamaguchi-sg5zr]

@@apwells All that makes perfect sense. I hope Brent has considers all these things before he completes his project. Thank you very much!

[@claykresser7110]

I studied construction management at Ohio State, and we would tour campus buildings that were being built on as part of our classes. They were building a new arts building with a full blown movie studio in it. The entire floor and wall framing was completely isolated from the rest of the structure and if i remember correctly there were 11 layers of drywall between both sides of the wall. Was pretty cool to see something unique like that being built. Awesome video as always!

[@cborecky]

11 layers? Might as well brick it.

[@BrentHull]

Interesting. Thx.

[@JamuelSames]

I’m doing a commercial theater project and we use very similar details. Very cool. Sounds like you’re using a very thick STC door? Manufacturers like Oregon Door or Wenger make more useable, ADA compliant doors with similar STC ratings. My understanding is that those big doors are based on old technology and old designs. not many manufacturers have gone through the extensive sound transmission testing on newer designs, so they just keep their thick heavy doors and cam lift hinges

[@BrentHull]

Ok. Thanks.

[@Real_Tim_S]

This topic I actually have a ton of experience with - in the 1990s when I was building custom homes, we specialized in adding home theaters (because that's what we started doing, expanding into whole homes later). Later we expanded into commercial buildings and did a few studios and theaters. STC ratings are made possible by: Isolation, absorption, diffusion. Sealing and decoupling leads to isolation, mass and material thickness lead to absorption, and surface treatments and shapes lead to diffusion. Isolation covers both airborne and structure borne noise, any way that air can pass can transmit the pressure changes in air that makes up sound - and vibration of equipment or the building itself (via acoustic coupling of airborne noise to say for example large flat surfaces perpendicular to the noise wave) that can pass from one place to another in the structure. Coupling itself is a statement in the reception and transmission efficiency of one medium to another - and is most often frequency specific. Generally a lower mass medium is inefficient at transferring its energy into a higher mass medium (so air has trouble imparting its energy into say a block of concrete, however it can be more efficient at reflecting that energy from the air) - a material that accepts energy from a medium but changes the rate as it passes through (like Rockwool) can soften that energy as it passes. Sound being a pattern of waves at a given frequency can be disturbed by adding a shape to a surface that works in the time component of the reflection, by reflecting portions of the sound energy at different delays, thereby creating a destructive interference pattern (5 - 4 = 1, because you'll never have 100% efficiency realistically, it's about maximizing the effect you're after). Some stuff you can't perfectly eliminate - air passage leads to coupling, but we call air passage in construction "ventilation", so it requires a specific type of treatment that can still allow the passage of a steady flow of air (a static pressure, like a DC current), but blocks the vibrating passage of sound (increasing and decreasing pressure at a given repetition, like AC current) and acoustic duct with a silencer (like a muffler on an exhaust pipe, which serves the same purpose) can make this work. Some passages are harder to deal with, like those you want to see through or walk through, but there are ways to deal with both sealing, and the diffusion of sound reflected (because glass is a large flat hard surface... on modern buildings, but it COULD have double hung with individual panes, intentionally angled to redirect the reflected sound!!).

[@BrentHull]

Thanks so much!!

[@gregpendrey6711]

Top comment.

[@rogerhodges7656]

Your floor detail should minimize the direct sound transmission through the floor. You have the mass right with two layers of 5/8" drywall. I couldn't tell from your detail but, I hope that you have two separate bottom and top plates that are not touching each other. Also, be sure to use an acoustical sealant (caulk) around the edges. Avoid having and receptacles or switches on common walls. If Code or an inspection forces you to have those penetrations of your sound barrier envelope, detail them appropriately. Good luck!

[@BrentHull]

Thanks, good info.

[@artemioquintero7866]

Double 2 by 4 Walls not touching is a really nice detail. I'm a framer I've done stuff like that on commercial applications.

[@BrentHull]

Cool thanks.

[@krogg5868]

The details on air sealing will be crucial. Good luck!

[@BrentHull]

Thanks.

[@TonyaO2L]

Looking forward to any updates.

[@BrentHull]

yes sir

[@samhooley1915]

Are you going to be installing standard 5/8 gypsum or an acoustic gypsum? I know at my yard we stock something we call soundboard that's designed for sound transmission.

[@BrentHull]

Plans call for 2 layers of 5/8 gyp. We may also put a sound strip/board up as well. More to come.

[@cborecky]

I've heard denim insulation (i.e. shredded blue jeans) actually beats rockwool for sound deadening.

[@BrentHull]

Ok, didn't know.

[@KenYamaguchi-sg5zr]

Great Job, Brent. Thank you. Double layers of drywall and two staggered walls with a 5 inch gap between them is great. For inside the walls, I presume you'll install something like Rockwool which is recommended to quiet walls? Also did you consider installing sheets of Mass Loaded Vinyl Rubber (for example Acousticmac or AudioSeal)? I've read a lot about this material and it's effectiveness. Also have you considered covering the studio walls with sound absorbing panels such as commonly used in recording studios? For the floors, you said you'll use AdvanTech subflooring. Have you considering a layer of Mass Loaded Vinyl Rubber below that? I'm not sure but I think that would help insulate the floor from the vibrations emanating from the spin cycle machines into the floor and into your offices. Speaking of flooring, are you considering a final floor in the spin studio of rubber to further absorb the vibrations from the machines? I think it would also help dampen echoes. Have you considered a raised subfloor with insulation underneath? Speaking of echoes, are you planning anything for the ceiling such as acoustic tiles or a drop-ceiling with acoustic squares? For a neighbor with music blasting and shouting, you might consider something more extreme such as hanging vertical baffles across the noisiest spaces (for example Versare, EchoAbsorber, UdderlyQuiet and Cardinal wood fiber hanging baffles). Finally, for that heavy door, exterior door weather sealing is useful, and there are mechanisms that attach to door bottoms that will plunge a seal down to better close the air gap once the door is closed. Thank you. I really appreciate your posts.

[@DrMJJr]

MLV is definitely the way to go for acoustical deadening!!! A little (2) lb. per sq.ft. AudioSeal would fix those issues right up!!

[@BrentHull]

Thanks, great feedback.

[@gregpendrey6711]

The door is crucial and no matter how thick I think double adjoining hotel configuration with the threshold seal and weather stripping will be necessary. I read the literature for airport sound abatement for SeaTac international and they basically build another envelope over and around the existing homes. All air infiltration must be blocked on both envelopes. Fresh air is brought in through specially baffled ducting with powered pressure balancing units.

[@kentonbolte931]

Would you consider fiber glass insulation between the two walls? I've seen this is a couple of projects I've worked on.

[@BrentHull]

We're pretty committed to Rockwool at this point. They have a sound batt that works great.

[@robertbamford8266]

Insulation in those interior walls? Made a huge difference in our exterior walls.

[@BrentHull]

?

[@robertbamford8266]

@@BrentHull Blown in insulation made a significant sound reduction in our exterior walls. Where sound is an important factor I assume it might be worthwhile to consider in an interior wall.

[@josephavila7178]

*Sound Transmission Class, not coefficient. I think you're confusing NRC (Noise Reduction Coefficient). With all the music and exercise content, I'd think you'd also need some resilient clips for the walls and isolation pads for all the cycling equipment. Who do you have doing the acoustical consulting work on this project?

[@BrentHull]

Noted. Thanks. Sounds like we need one.

[@larrywave]

😁👍

[@BrentHull]

Thx.

[@AdamTillontheWeb]

Neat. People dropping weights will still be a challenge to avoid hearing

[@BrentHull]

We'll see.

[@spilleradam]

What about insulation, won’t that help with sound.

[@BrentHull]

Yes, we are using Rockwool. Thx.

[@garyhenderson9303]

This seems to be all wrong, If you cannot hear them doing their fitness surely you have created something like Schrödingers Cat where if you cannot hear them they are not actually doing anything?

[@error-xn7hn]

Sound consultants don't mention this enough

[@BrentHull]

Haha, I hope I have that issue.

[@AnthonyAnthony-tk4ye]

Mineral wool…

[@BrentHull]

Yes. Thx