100% Sound Proofing (1 Viewer)

[JasonKMonroe]

OK...this is my first post on the HTF, although I have been browsing through for the past year or so. The time had finally come, and my wife and I bought our first home. I have always wanted a dedicated home theater, but lacked the space and the ability to knock down walls and what not

Now that I can finally go through with this, my question to you all is :
Soundproofing?
The theater room is on the main living level, with one entrance (27ft x 20ft). The problem lies in the fact that there are 2 bedrooms immediately adjacent to 2 of the walls. What type of soundproofing material will completely block ALL SOUND, yes, 100% of it, from permeating the walls. We have a budget of roughly $25,000 for the construction (soundproofing, risers, new cieling, built in speakers, etc..). Is what I am looking for even obtainable within this price range?
I have read about various existing types of soundproofing material, such as the insulation walls, blow-in soundproofing foam, etc., but I do not believe this will work. If I am mistaken, please correct me.
Again, I have enjoyed being a 'silent' member of HTF and am really looking forward to being an active conversationalist here in the future.
Thanks for any help,
- Jason

 

[Wayne Murphy]

Good luck on 100% soundproofing.
The best type of sound proofing you can do with your set up will probably be to build another wall betweeen the theatre and the bedrooms. Insulate with Roxul insulation between the two walls. When you go to finish the outside of the new wall (inside the thestre room) use z channels.
They area piece of metal bent like a z shape if viewed from the end. One side is secured to the studs and the other side to the drywall. The idea is that sound waves hitting the wall will not travel right through the drywall-stud-out the other side drywall. The flexibility absorbs a lot of the vibration. Use 5/8ths drywall to help deaden the sound as well. I've heard of people also putting on 2 layers of drywall. I don't know how much this helps though.
Don't forget the joists in the ceiling and floor if they run into the bedrooms sound can travel in there as well.
The heating air conditioning ducts have to be taken into account also. You may want to wrap them with sound deadening material as well.
In my theatre the most sound leaks through the back of the staircase. Even though I insulated and put drywall on it.
Look caefully at your room and try to figure everyway sound can travel to the bedrooms. Then ask here to see what people suggest as a way around the problem.
Hope this helps.

 

[Dave Milne]

Jason, There's no such thing as 100% soundproofing. Sound transmission (or attenuation) is measured in dB. Since dB is a logarithmic scale... there's no zero! I think what you mean is that you don't want to hear the theater at all in the bedrooms. How much attenuation this requires depends on a number of factors including the ambient noise level in the bedroom, your hearing threshold, etc. In a quiet neighborhood, a well insulated house probably has an ambient sound pressure level (SPL) of 30-40 dB (for simplicity, we'll forget about the various weightings applied to sound measurements). SPL in the theater can probably reach 110dB with a decent set of amps and speakers. This means you're looking for 70-80 dB attenuation. This will be VERY difficult to achieve --especially at the low frequencies. As Wayne suggested, building a "double wall" with a couple of inches of air gap in between and insulation will get you into the 55 dB range. If you double-drywall the theater, use z-channels, and/or lead-sheet acoustiblok damping, you might get 65 dB. If you're that serious, you'll need to make sure there are NO air gaps... seal all the electrical boxes and get an acoustic door with 360 seal (expensive). If you have common floor and ceiling joists you're probably limited to 40-50 dB attenuation in the bass. The only way around this is to build a complete "room within a room". And don't forget about windows. Even double-pane windows are good for only about 30dB of attenuation. Sound could travel out the theater window and into the bedroom window!
Good Luck!

 

[JasonKMonroe]

Thanks for the responses guys.
Here is the total scenario :
The bedrooms bordering the theater room are the Master Suite and what will hopefully be a childs room within the next year. That is why I am trying to plan all of this out correctly.
The ceiling joists flow right over the other 2 bedrooms; this will allow a path for the sound to travel right?
The duct work, however, is not connected. I really have no idea what the couple who had the place before us did, but there is a separate A/C and heating unit for that room. *shrug*
The ceilings are not open to each other. They are closed off. (its like that everywhere, not just that room)
So it would seem to me that I would get the most sound dampening if I were to build a false wall about 4 feet out from the existing walls, use those z-area supports, soundproofing insulation, and then possibly those rubber absorption mats(anyone know about these?).
The main concern is getting the ambient sound down to 'acceptable' levels, meaning that I could be watching The Matrix at 2:30a and Natalie could be sleeping (baby too once one comes along

I am sorry about my earlier post.
Knowing what I do about sound waves, I would think that my main problem would lie with the subwoofer. But, I cannot see how anyone can stop the lows from escaping a room. Anyways, please let me know what you think of my current idea. Time frame is running down, construction should start around Feb.

 

[Wayne A. Pflughaupt]

Jason,
Not wishing to turn this into a “child rearing” forum, but…
Do yourself a favor and “train” the baby to sleep through the noise. I’m not kidding! I’ve raised three kids and this is what I did.
I know people who basically “shut the whole house down” when the baby took a nap or bed down for the night—all activity, especially anything that made noise, came to a stop. No TVs or stereos on, no clattering dishes in the kitchen, unplug the phone, sign on the front door, “Do not ring bell,” etc.
Know what? The baby would wake up at the least little sound or noise!
I never did this. I kept their bedroom doors opened and the TV or stereo stayed on, and so did anything else that happened to be going on. The baby would drift off and sleep through it all.
As Dave noted, the noise floor is important, too. Raise the noise floor in the baby’s room and the sound deadening becomes more effective. You can accomplish this by putting a box fan in the nursery room and run it on a medium speed. This will raise the noise floor and help mask the sound from the theater room.
With the training, the fan, and the sound deadening, the baby should be able to sleep like a…well, you know!
Regards,
Wayne A. Pflughaupt
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My Equipment List

 

[Deane Johnson]

Do yourself a favor and follow Wayne's advice. It works, it makes life smoother for everyone including the baby, and it sure saves a lot of money.
I suspect 100% sound deadening would require about 24" of concrete. It would be much easier to "condition" the baby to accept a certain amound of sound as "normal".
If there is any more advice you think you might need on raising the kid, don't hesitate to ask.
Deane

 

[JasonKMonroe]

Ya know, I guess you're right. Personally, I have to sleep with some noise (always a fan). If there isnt any, I cant sleep. Same principle I guess. But nonetheless, I would still like to keep ambient noises down, so here is what I have decided I am going to tell a contractor.
Okay, picture the room, a big rectangle, with the back wall facing outside, and the far wall (from the door) facing outside. The wall on the opposite end from the windows is bordering a bedroom, and the wall that the entrance is on borders a bedroom.
Here is my game plan. Build a false wall, 4ft out from the 2 walls that border the bedrooms. Because the entrance to the theater will be in the back of the room, it will work OK. The false walls will be soundproofed as best they can be. Behind the false wall will be a hallway of sorts. This will allow me to flush mount all equipment and still have easy access. It will also let me add a .5 bath. At roughly 3.5 ft wide x 5 ft long, it will be a tiny bath, but still get the job done
The screen (still in research phase, but looking at Stewart Grayhawk 110") can be wall mounted.
Speakers: I know that there is probably a better place to ask this, but because there will be that hallway behind the false walls, do you think that I could install the speakers flush with the wall?
Anyways, thanks for all of the advice. I guess having some noise will be a good thing. Thanks for reminding me I had common sense And please let me know what you think of my plans.

 

[Wayne A. Pflughaupt]

Sounds like a good plan, Jason. If possible, why not design the 2 bedrooms so that their closets are on the side of the room closest to the home theater room? That would put more space and sound-deadening (clothing and dead air space) between it and the kiddos.
Regards,
Wayne A. Pflughaupt
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My Equipment List

 

[Guy Kuo]

Fade in to dimly lit room with walls barely discernible as ominous atmospheric cue circulates around the room.....

In Jason's room, you can scream but no one care hear you.

Bright flash and a scream.... fade to black ...