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New Construction Question Walls Sound Isolation Methods

8K views 66 replies 15 participants last post by  cw5billwade 
#1 ·
Hi, I’m just starting my research into a dedicated home theater.

This will be for a new construction of my residential home.

The home theater will be on the 1st floor of the home.

Two of the four walls will be exterior walls.


I’m trying to figure out what construction methods and materials will be needed for the build out.


The first question I have is on wall construction.

I understand that I’m looking to add sound damping, provide decoupling, and increase mass to my walls to achieve soundproofing.


I have been reading and see there are many different combinations out there for sound isolation:

Single Stud Wall with Resilient Channel or Hat Channel

Single Stud Wall with Sound Deadening Board


Staggered Stud Wall

Staggered Stud Wall with Sound Deadening Board


Double Stud Wall

Double Stud Wall with Sound Deadening Board


Building a decoupled room within a room


As I said I’m just starting my research.

Anyone have suggestions on how to narrow down my options further?

Or have a recommend way to build out the walls?


Thanks!
 
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#52 ·
You are correct. Many times people confuse soundproofing with acoustical treatments inside the room. However, soundproofing can be a very key component of acoustical treatment.


A soundproofed room will still echo and sound bad from reflections, standing waves, so on and so forth. However, having a room with some soundproofing encorporated into it will also reduce outside/external factors that can impact the sound. The wife making you an ice cream treat in a Ninja blender in the kitchen, the neighborhood kids outside playing, etc. Those all impact the quality of the sound inside the theater.


But that horse has been beaten to death. You do get more "bang for your buck" in sound quality inside a room with acoustical treatments, something that I have still yet to finish in my theater, but the few things I've done with treatments has made a big difference. I just need to get some more diffusion in my rear corners (as in putting in my movie/media storage in one corner), put some absorption on the back wall, and do first reflection point absorption. The floor, ceiling, front vertical corners (bass traps) and front wall are all treated and that made a huge difference.


So when you are ready, open up some more threads on the other topics. As you can see, there is no shortage of advice around here.
 
#53 ·

Quote:
Originally Posted by nickbuol  /t/1479164/new-construction-question-walls-sound-isolation-methods/30#post_23491559


Mfusick, I know that you don't care about keeping your grass up in the middle of the night, but here is something to think about.


There was a guy down the street from us in our old neighborhood that had a "bonus room" above their garage that was finished into a home theater. Zero soundproofing was done. They had no kids, and it was always just him and his wife so they didn't care about the sound in his house. They didn't watch a TON of movies... Maybe one or two a week tops, but when they did they started them around 9:30 or 10:00pm.


It wasn't long before they started getting complaints from some of the neighbors. They used "anonymous notes" and even going as far as calling the cops for a noise disturbance.


I had seen his theater and we even watched a movie (one of the Star Wars prequels) during a rainy Saturday. He really didn't have it any louder than most normal people would have it, and said that was how loud he always had it.


So "normal" volume levels inside the theater, zero sound proofing, the grass, car, and lawnmower were kept awake at night and so were some neighbors.


So you can do what you wish, but keep that factor in mind. While soundproofing easily helps with the sound floor in the theater and that seems to be the main focus of "people in the know," it still serve another purpose of keeping sound inside the theater... At least to some extent.


So when you talk about waking your lawn, living in a quiet neighborhood, and that you have really no noise pollution in your theater, that means that you watch movies at night, live in a neighborhood that will easily notice your theater running, and you will become the source of the noise pollution.


Not criticizing, but just bringing up some (hopefully constructive) counter-points to what you said.

Thanks !!!!!


Great points !
 
#56 ·
People think "very quiet" is library quiet...about 33 to 35dB. Movies think quiet is 22dB. In a room not sound isolated, the difference between the noise floor in the (very quiet) room and the softest sound on a sound track is right around a factor of 8. So, not a problem right? Just turn up the volume to hear soft dialog, foot steps, leaves in the wind. That's fine; but, having done that, normal dialog and "normal" sound is also going to be played back 8 times louder...not so fun. The loud sounds...also 8 times louder and, in many cases, beyond the capability of mid-level amps and speakers.


For the record, those with hearing loss or even tinnitus benefit more from lowered noise floors (and good acoustics) than those with good hearing now (which will be pretty bad hearing in the future due to an overly loud movie or gaming room).


"I have poor hearing. I don't need sound isolation or good acoustics." That is nothing more than rationalization and horse poo-poo.
 
#57 ·

Quote:
Originally Posted by rabident  /t/1479164/new-construction-question-walls-sound-isolation-methods/30#post_23489915


Keep in mind that the definition of "soundproofing" for HT, according to the professionals, is primarily to lower the noise floor within the room. Dennis's famous line for his designs are "Don't care if the noise wakes the baby, but ensures you won't hear the baby when it wakes" - or something to that effect. I see most people sold on soundproofing due to situations like yours, but when you get down to brass tacks, that's not what you're buying. If you want to crank Iron Man 3 on a capable audio system while the kids sleep upstairs... you need to invest in a good pair of headphones.


There have been several threads outlining what it would take to truly sound proof a room in the layman's sense of the term. The point was to level set that if you understood the physics involved that you couldn't realistically expect it. Something like 6' thick concrete walls, or "castle walls".

Are you saying that after all of this investment, if you want to listen to iron man or a movie with good LFE at movie theater volums w/o disturbing the kids upstairs - the OP's suggestion - decoupled walls with wall within a wall + DW + GG+GW - is not going to achieve that goal?????

Anyone else care to chime in?
 
#59 ·

Quote:
Originally Posted by cgott42  /t/1479164/new-construction-question-walls-sound-isolation-methods/30#post_24115584


Are you saying that after all of this investment, if you want to listen to iron man or a movie with good LFE at movie theater volums w/o disturbing the kids upstairs - the OP's suggestion - decoupled walls with wall within a wall + DW + GG+GW - is not going to achieve that goal?????

Anyone else care to chime in?

I was responding to BillDo, who I quoted, who said he had a small home and an existing HT that he was going to tear down & rebuild with soundproofing so he wouldn't wake his kids in bed.
Quote:
Originally Posted by BIGmouthinDC  /t/1479164/new-construction-question-walls-sound-isolation-methods/30#post_24116056


If you follow all the recommendations for soundproofing a theater space, you will not disturb the kids in second floor bedrooms.

Including this one?
Quote:
Originally Posted by Ted White  /t/1437703/building-a-new-house-around-a-theater-how-to-contain-low-frequencies#post_22569024


if you want to start slowing down 15Hz frequencies, the fundamental resonance point of the would need to be 10Hz. Maybe 12 sheets of drywall on either side of a 2 foot deep decoupled wall.
 
#61 ·
Theater of the month a while back.
Quote:
Originally Posted by vikgrao  /t/1489162/home-theater-of-the-month-vikgraos-fortress-of-solitude/0_40#post_23702522


Its not just insulation for the room walls and ceiling, but insulation coupled with the principles decoupling using clips, Green glue and and adding mass using layers of drywall. i knew going more thicker on the door wont completely solve any leaking problems which may arise.


We had some issues with doing double doors with air gap at that time. The current door is 2.75 inches but does have zero international seals all around the perimeter along with automatic door bottom seal to prevent leakage. Also the 1/2 inch mdf layers in the door with green glue really help in absorbing the sound along with the treatment covering the door from inside.


When the door is closed and i am playing at reference levels there is hardly any sound escaping out. Also with the door closed no matter how noisy the outside of the theater was I do not hear anything inside and my Calibrator Jeff meier recently measured a NR of 18 inside the theater.


Still I am planning this year on building a entryway/booth to the theater in front of the original theater door and add a second door plus seals.

Vik likes to play his theater loud, So loud I could not stay in the room. His wife works all hours on rotating shifts and trust me his theater doesn't disturb her. That was one of the basic reasons Vik used the soundproofing principles. He is using Seaton Catalysts and a JTR orbit shifter sub.
 
#62 ·

Quote:
Originally Posted by rabident  /t/1479164/new-construction-question-walls-sound-isolation-methods/30#post_24117112


I was responding to BillDo, who I quoted, who said he had a small home and an existing HT that he was going to tear down & rebuild with soundproofing so he wouldn't wake his kids in bed.

Including this one?


Originally Posted by Ted White:


if you want to start slowing down 15Hz frequencies, the fundamental resonance point of the would need to be 10Hz. Maybe 12 sheets of drywall on either side of a 2 foot deep decoupled wall.

I saw on the post that you linked to that very, very few movies go down below 20Hz .

And if you were trying to contain ~25Hz, "just" 4 sheets of DW is needed (though I'm not sure if that presupposes the same 12" gap)


So I'm guessing the point is that most movies don't go below 30-35Hz and thus people are happy w/2-3 sheets of DW as mass.

Curious - does anyone know how low is the lowest freq. of a normal blockbuster (e.g. Lord of the Rings)?


More importantly - I see that the size of the air gap really helps contain the LFE, and thus 12" is needed for really low LFE. However, it seems that most leave just a 1" gap -why is that? Obviously you don't want to sacrifice HT space - I get that - but wouldn't it make more sense to give up a few inches - i.e. why just 1"? Also - is it really - the bigger size the better? As I was considering leaving 2' in one area - as I have a sump pump that I'm building over and need to leave access to.
 
#63 ·

Quote:
Originally Posted by cgott42  /t/1479164/new-construction-question-walls-sound-isolation-methods/60#post_24117581


I saw on the post that you linked to that very, very few movies go down below 20Hz .

And if you were trying to contain ~25Hz, "just" 4 sheets of DW is needed (though I'm not sure if that presupposes the same 12" gap)


So I'm guessing the point is that most movies don't go below 30-35Hz and thus people are happy w/2-3 sheets of DW as mass.

Curious - does anyone know how low is the lowest freq. of a normal blockbuster (e.g. Lord of the Rings)?

A few posts down the OP linked to the AVS collection of waterfall plots for movies http://www.avsforum.com/t/755493/the-master-list-of-dvd-hd-dvd-blu-ray-movies-with-bass-thread-with-waterfalls . Lord of the Rings is listed with content down to 8hz. IronMan shows content below 10hz. The list shows plenty of movies with content below 30-35Hz. Believe what you want.


As for 4 sheets of drywall @ 20Hz, Ted said not to quote him on that (in that thread).
 
#64 ·

Quote:
Originally Posted by cgott42  /t/1479164/new-construction-question-walls-sound-isolation-methods/60#post_24117581


I saw on the post that you linked to that very, very few movies go down below 20Hz .

And if you were trying to contain ~25Hz, "just" 4 sheets of DW is needed (though I'm not sure if that presupposes the same 12" gap)


So I'm guessing the point is that most movies don't go below 30-35Hz and thus people are happy w/2-3 sheets of DW as mass.

Curious - does anyone know how low is the lowest freq. of a normal blockbuster (e.g. Lord of the Rings)?


More importantly - I see that the size of the air gap really helps contain the LFE, and thus 12" is needed for really low LFE. However, it seems that most leave just a 1" gap -why is that? Obviously you don't want to sacrifice HT space - I get that - but wouldn't it make more sense to give up a few inches - i.e. why just 1"? Also - is it really - the bigger size the better? As I was considering leaving 2' in one area - as I have a sump pump that I'm building over and need to leave access to.
In the for what it is worth department if you have a decoupled wall with a 1” gap than in reality you have DW/GG/DW/3 ½”/1”/3 ½”/DW/GG/DW making the air gap between walls 8”. You can make the gap between studs 5” if you want the entire 12” gap but not necessary if you put the R13 in both walls. The lower frequencies see the insulation as a larger air gap. Just my onion based on research including the effect of insulation in a IB Subwoofer chamber.
 
#65 ·

Quote:
Originally Posted by fumarate  /t/1479164/new-construction-question-walls-sound-isolation-methods#post_23472859


Hi, I’m just starting my research into a dedicated home theater.

This will be for a new construction of my residential home.

The home theater will be on the 1st floor of the home.

Two of the four walls will be exterior walls.
What is above and below the theater? Is it a slab build or basement or craw space? Is there another room above the theater or just attic?

I’m trying to figure out what construction methods and materials will be needed for the build out.


The first question I have is on wall construction.

I understand that I’m looking to add sound damping, provide decoupling, and increase mass to my walls to achieve soundproofing.
How much space are you willing to give up? I used IB1 Clips and hat channel on my side walls, front wall and ceiling. I used a decoupled wall at my rear. My theater is above the garage and the only wall that is common to the house is the rear wall/billiard room. I did not mind giving up the additional 4 ½’ in the rear but felt I could not afford it in the side and no need for it in the front which is why the IB-1 clips (poor man’s whisper clips) My room is a total shell the only openings are for the wires which enter in my soffits and the window and door. I used a window plug made the same way as my walls except I used MDF vise DW. I also used another layer of 3/4" T&G on the floor with GG in between

I have been reading and see there are many different combinations out there for sound isolation:

Single Stud Wall with Resilient Channel or Hat Channel my side walls, front walls and ceiling

Single Stud Wall with Sound Deadening Board


Staggered Stud Wall

Staggered Stud Wall with Sound Deadening BoardNot sure what you mean by sound deadening board I used one sheet of 19/32” OSB/GG/ 5/8”DW so OSB/GG/DW. I used the OSB to better fasten my soffits coffers and columns. With 2 layers of drywall there is really nothing to attach them to.


Double Stud Wall My wall between the theater and billiard room

Double Stud Wall with Sound Deadening Board


Building a decoupled room within a room


As I said I’m just starting my research.

Anyone have suggestions on how to narrow down my options further?

Or have a recommend way to build out the walls?
How much space are you willing to give up? I used IB1 Clips and hat channel on my side walls front wall and ceiling. I used a decoupled wall at my rear. My theater is above the garage and the only wall that is common to the house is the rear wall/billiard room. I did not mind giving up the additional 4 ½’ in the rear but felt I could not afford it in the side and no need for it in the front which is why the IB-1 clips (poor man’s whisper clips)If you have the space to lose the 5 ½” then I would recommend the IB-1 clips on the exterior walls and decoupled walls on the inside walls. Looking at the speck sheets on the SoundProffingCompany web site it does not make that much of a difference so if you wanted to save 5” in width and length than just go with IB-1 Clips and Hat channel for all four walls and the ceiling. You have to address the floor either way whether it is a slab or a basement/crawlspace you just use different methods but should be addressed prior to the decoupled wall not as important with IB-1 clips.

Thanks!
You have to take into account the flanking noises like everyone else pointed out. That is why I did the additional 3/4" layer of T&G OSB and GG on my floor. T&G/GG/T&G. Since I was above a garage I did not use the serenity mat. I also used acoustical caulk on the primary floor between all the 4x8 sheets and then again on the top layer. Prior to installing the clips and hat channel put your R13 or R15 if exterior wall into the studs R 19 in the ceiling joists if between rooms or R35 if attic. For the side walls front walls and ceiling I used the IB1 clips and the hat channel. Insure none of your first layer (in my case OSB) touches any of the studs or joists when you hang them. For my rear wall I did a decoupled stud wall held in place with four IB-3 Clips. Again I put R13 in the billiard room wall and also in the theater wall. After the OSB was up on the walls and ceiling I used the caulk again in all the cracks. My wife thought I was nuts. My friends accused me of doing that so I did not have to do any heavy lifting. I think I went through 2 cases of caulk. Get the white stuff not the black messy stuff. Once the OSB is up you install the GG to the back of the drywall and lift into place. Insure you drywall is hung so it covers the OSB cracks in the middle. I.E. you do not want the cracks between sheets of DW and OSB to line up, offset them. Once this is done you have a totally sealed room and it is time to think about getting you power and AV wires into your space. I predrilled my studs and had all of my wires pre ran so I could bring them in as I went. All were run through the soffit, columns coffers and stage. I pulled some wire for the riser as well. Check out my build. I am not an expert but I have stayed in a Holiday Inn Express.


Sorry if I got repetitive and took up to much of your thread but it seemed that other folks questions were being answerd but not yours.


Funny story with the R19 in the ceiling and OSB/GG/DW was so good at attenuating the sound of a human voice when we were doing the HVAC I was in the attic and saw this hand stick up through the hole we cut for the HVAC line with my cell phone in it. My friend said he was tired of screaming from below and sticking his mouth near the hole did not seem to work.

Sound proofing works if applied properly I cannot hear the TV playing in the billiard room when the door to the theater is shut or a lawn mower or the random loud exhaust guy driving buy. On the other hand playing a movie or song at reference I can just make it out standing in the billiard room with the door shut. Open the door and my buddy said crap that was really loud in the theater wasn’t it? LFE stills sneaks out but my AVR has a setting for that and I have not sealed my door yet.
 
#67 ·
I have the Denon X4000 the setting is dynamic voice it has 3 settings Heavy which is called Midnight in other AVRs, medium and light which is called day time in some AVRs. It raises the voice and lowers the base when you turn the volume down the voice stays at a comfortable level. The X4000 also has the LFC setting which is reported to reduce low frequency through walls it has 4 settings At 20Hz, toggling through LFC values of 1,2,3, and 4 results in a decrease of -15dB, -20dB, -24dB, and -27dB, respectively. Here is a link to the test
http://www.avsforum.com/t/1430049/the-official-denon-avr-4520ci-thread/510#post_22525837


LFC is not on the x3000 or lower models but dynamic voice is.
 
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