Hello AT,
My roommate and I share a railroad apartment, we want to close the door in the center. I have done this, covered it with foam and then covered it with vinyl held with fabric tacks but it still sounds as if he's right next to me. Is ther any recomendations for insulation or a person who could fill the door in for me on the cheep?
All help appreciated, Russell
The thing that we have learned about sound is that to stop it you need a combination of a hard surface outside and air pocketed inside. This is what hollow-core doors do. You could either take the existing door out, foam the inside and place two thicker pieces of Luan on either side to seal it off or you could place luan on top of your existing door, sandwiching it inside. If you send in pics, we could say more.... (Thanks, Russell!) MGR
Also making sure the rim of the door is sealed ( has a foam gasket, for instance) tops, sides and bottom is critical.
Actually, hollow-core doors will be useless to you. What you really need is isolation. The technique of mass/air space/mass only works if the two masses are not mechanically joined. Unfortunately, the side edges of the door provide a lovely join, negating the airspace in the hollow core door. In addition, the empty space in the door makes for a lovely resonance that will cause a whole new set of problems (think of a drum. if your roommate produces the right frequency noise your door will buzz and rattle in its frame).
You need mass, decoupling, damping, and sealing.
First the mass - replace your door with the heaviest solid door you can find.
Next, the decoupling - This will be hard to do without ripping out your whole wall. Unless you want to build a false wall a few inches away from your current one and totally seal over your door, let's leave this one alone.
Damping - Anything you can do to damp the vibration caused by the noise your roommate makes will help. To damp you want heavy mass in front of something a little squishy. The best way to do this would be to make new facing for your door on your roommate's side (or both to be nice to each other). A thin layer of drywall or luon (drywall is better because it's got more mass) over something squishy (like a pre-made accoustic damping compound such as automotive vibration damping spray or Green Glue).
Sealing - Sound is like water. If there's an opening, it will find its way in. You need to seal the door around all the edges using the best weather stripping you can buy. Not a cheap piece of sticky foam. Zero International makes nice gaskets (you'll want the cheaper rubber ones), though their website is real pain. You want to prevent any air leakage from the door (around the edges, through a keyhole, etc.)
If you do want to totally cover the door the best way to do this would be to build a false wall an inch or two out from your current wall. Make sure that NO part of this false wall touches your current wall. Use a double layer of drywall, and a damping compound if you can afford it (that stuff isn't cheap, about $300 a bucket that will cover 300 sqft of wall). Of course, if you have electric service in this wall that would complicate things.
This month's ReadyMade had a sound-dampening wall made out of blue foam. Industrial Plastics on Canal sells it and can cut it for you as well. Go for thick. Books are also a great sound-dampener -- they're thick and dense and trap sound... Neither of these suggestions are as good as Max's, but moving bookshelves onto the wall that runs between the two of you is a lot cheaper than damping compound... You can seal off your door, but maybe there's a way to lower the resonance of sound in your rooms as well.
Dealing with sound in a room is a different animal than dealing with sound flowing out of a room. Within a room you are working with absorption.
When a space has too little absorption it is too "live" (think noisy restaurant where you can't hear your friends, like Rice Republic).
When a space has too much absorption it sounds "dead" (think eerie quiet where noises just get sucked up).
Different things absorb sound at different frequencies. Things like carpet and wall hangings are good at absorbing high frequencies, but are useless for low frequencies. Things like cushions and couches absorb a broader spectrum.
Though this has little to do with Russell's problem of sound transmission, it raises an interesting point. Spaces that sound nice are much nicer to live in!
If your room sounds echoey, or footsteps ring out uncomfortably, your space is too live. You need broadband absorption in the form of books, cushions, upholstered furniture, or specially made acoustic panels (these can be made on the cheap if you are handy, and can look beautiful if covered with nice fabrics).
If your space seems to suck all the energy out of conversations, or seems oddly quiet, liven it up with some reflective surfaces (glass fronted pictures, rolling up a rug to reveal a wood floor, putting doors on bookcases).
Sorry for the long post, I'm a complete audio geek if you couldn't tell and I just can't stay away from threads like this!
Max,
Audio geek is good. Audio geek is way good.
Is there any way I can send you an email asking about my ceiling? I stripped a ceiling to the beams for the height & while it's not very noisy, I'm wondering if there's any kind of sound insulation that I should put up before I put strips of sheetrock between the beams (and yes I know the beams themselves will carry the sound, so there's not much at stake here).
Hi Diana,
I'm always happy to help people out. The email should be in my name under the post. What I would do to minimize sound transmission from the floor above is hang the sheet rock from RSIC clips and hat channel. The clips are little "grabbers" that are separated from whatever they are hung from by a rubber bushing. Then you put hat channel (a thin bent metal channel) onto the clips, and screw the sheetrock into the channel. You've now decoupled your drywall from the ceiling above. Fill the space with loosly packed isulation of any kind to help prevent resonance. To make sure that you're not simply connecting your new drywall bits to the beams, make sure you've got a 1/4 inch gap between the drywall and the beam and seal it with acoustic caulk.
Of course, a more effective way would be to hang the RSIC clips from the side of the beams, and totally cover the ceiling. You could do this and only sacrifice about 1/4 inch plus the width of the drywall. Then you could create faux beams underneath to complete the look. Presto, a nice beamed ceiling effect but with plenty of soundproofing!
Max -
I've posted at AT from time to time, mostly on construction and sound related matters such as this, and was going to post onto this as well... but after reading your posts I can add nothing. Perfect advice. Your "sound is like water" analogy is especially helpful, and accurate (I've used it myself, on occasion). Nice work! (BTW, is "accoustic caulk" that you mentioned substantially different from either vinyl or other rubberized caulking?)
Thanks Max -- you sound like you really know [and love] this stuff!
Peter, acoustisc caulk is a little different than other caulks. It stays slightly "gooey" for 50 years or so. This keeps it from acting as a mechanical linkage between the surfaces it separates.
I do love acoustics, I run a side business designing home theaters and I specialize in working with small NYC apartments. Sound has been a passion of mine for a while now.
Ok guys, don't quite know this thread... and don't quite know how to put this. here's the challenge:
I own a little office in a residential area which is awash with clinics and hospitals. The area also has a major power shortage (as in every other part of Lahore, Pakistan). So, what do I do? i get a generator to fill my power needs. Trouble is that the 30KVA generator that can power my airconditioning and computers, etc is a Chinese powerplant that belches out sound like there's no tomorrow. The gen set i need... Now I have a little room at the back of the office in which I have housed this little sino-beast. However, I have broken the wall to make way for a little intake in front of the radiator and have also placed the exhaust pipe outside. However, there has to be a ventilator fan to expel the hot air from the room. Also problematic is the iron door in the entrance of the itsy bitsy room.
Now I cannot buy MLV or any other types of fancy sound insulation in Pakistan. What i can get are styrofoam sheets (upto 2" thick) as well as old foam mattresses and good ol' sawdust.
How the hell do I insulate the generator's low end belches so that I do not disturb the neighbors?? I would really need some help on this one.
My idea was to dampen the sound by using styrofoam sheets glued on the one foot thick brick and mortar walls.
Any suggestions??? Really would appreciate some 'sound' advice!
Here's my problem:
I live in a duplex and spare one wall with my neighbor. My bedrom wall (north wall) connects to his kitchen, so I can hear the kitchen cabinets close and chairs slide across the tile floor also music. All of these are dull thunking sounds. The problem is the my north wall intersects with my east wall which is where my walk in closet door is only 1/2 clearance between the two. Because I can't do much construction myself and have limited funds I was wondering if you might have some suggestions.
Any help will be greatly appreciated.
Thank you
Lynda
Sound is like water good point, the best sound absorbtion product is lead sheating. Next is a 2 inch thick sheat of rubber.
If you have a sealed wall ie: Brick and some styrofoam sheats and some foam rubber, place one sheet of styro against the brick then a layer of foam rubber then another sheat of styro then calk all seams with the softest caulking you can find.
Good luck in Pakistan from Canada