Window Plugs ?

Started by chudforlife on 1 March 2009. 16 replies. In the Library under Doors and windows.

Originally posted at johnlsayers.com, topic 11745.

I have a question on what is the the best way to make window plugs. Heres my situation. I have 3 windows facing the street . The sizes are 74 x 32. I need to keep the street noise out ( as much of it as I can ) of my control room . Im on the second floor of a building that is located on a fairly busy street.My space is pretty much a apt. that has been turned into home studio. Im not worried about the sound getting out. I would like to make a removable type plug for these windows. I need to make something removable because I rent here . Ive looked into plexiglass with magnetic seals and 2 inch closed cell foam with a backer board . I was also wondering if making a plug with MDF and Green Glue with heavy duty hinges would do the trick ? Thanks for any help
Adding to the above videos, I have one comment on something you said:
... and 2 inch closed cell foam ...
Closed cell is next to useless, acoustically. It works great for heat, but does nothing at all for sound. You need open cell foam for sound. - Stuart -
Thanks for the heads up on the closed cell foam. I am thinking about building a plug like the one that is posted or going with plexi glass and magnetic seals Any thoughts ?? Do any of you guys have experience with plexi glass and the magnetic seals ? Here are the seals I was looking at http://www.acousticalsolutions.com/prod ... onlite.asp
I am thinking about ... or going with plexi glass
For isolation, you need mass and density. The density of glass ranges from around 2,400 kg/m3 to over 7,000 kg/m3. The density of plexiglass is only around 1,200 kg/m3. So, you'd need to use plexiglass that is at least twice as thick as ordinary glass, or three times thicker than some other types of glass, in order to get the same mass in your plug. So, you could use plexiglass if you want, but you will need it to be really thick. For example, if you calculate that 1/4 glass will give you enough isolation for your situation, you'd need 1/2 inch plexiglass to get the same mass (but it will still only be half as dense). If you can afford it, go with laminate glass (but it is not cheap!). If not, then perhaps consider other types of glass. - Stuart -
I am getting the price of the plexi glass later this week. I will also price the laminated glass. If its out of my budget I will make some plugs like the ones in one of the previous posts Here is the foam I was looking at http://www.soundaway.com/window_plug_s/56.htm Do you have any thoughts on this stuff ? I have my doubts
Like Stuart said, that foam is closed cell, you will gain nothing isolation wise from it. As for the plexi, personally I would stay away from it, but if you do want to use it for your plugs, you're going to need quite a bit of it, for it to be dense enough for what you are trying to achieve.
That "foam mat" stuff is next to useless. It will not work for your application. It might reduce the sound slightly, but nowhere what you need. At best, it will reduce some high frequencies a tiny amount, but it will do nothing at all to bass frequencies. The laws of physics still apply, not matter what advertising hype on a web site says, and that foam will not do what you want it to do. Not even close. Did you notice that the web site does not provide ANY technical specifications at all, regarding the performance of those products? That's the giveaway that it doesn't do anything useful. If it really did do anything useful, you can bet they would actually publish the figures. Since they don't, it is safe to assume that the figures are probably embarrassingly poor. Don't waste your money on stuff like that: it simply will not do anything useful. It has very little mass, and it is closed-cell, so it has no acoustical uses. The laws of physics say that there are only two methods for stopping sound getting from point "A" to point "B": put a vacuum in between, or put something rigid and really massive in between. Since it's rather hard to create a vacuum around your room, you are stuck with rigid mass. Foam does not have mass and isn't rigid, so it is useless for isolation. Foam is used for acoustic TREATMENT, yes, but not for isolation. Treatment and isolation are two entirely different things. And closed-cell foam is no use for treatment either: real acoustic foam is always open-cell, not closed cell. So, if you really do want isolation, then you will need to build your plugs with THICK glass, not with useless foam, and not with plexiglass. If you can't afford laminate glass, use normal glass, but it has to be thick in order to give you the mass and rigidity that you need to block sound. Or if you want to use plexiglass, then you need to make it TWICE as thick as ordinary glass, since plexiglass is only half as dense as real glass, as I pointed out to you yesterday. Bottom line? Forget cheap undocumented solutions, and go with real, proven solutions. - Stuart -
Thank You Guys !!! As I have been thinking more about it I am going to go with a window plug that is going to be made with 2 sheets of 3/4 MDF with 1 sheet of 5/8 Sheet rock between . I will also use Green Glue on both sides of the sheet rock. I have 11 inches of space so I can create about an 8 inch air gap between my existing window and the plug. I am also going to frame out the inside of my window sill with 2x2's . It will all be caulked with Acoustic Calk. The inside of the framing with have heavy duty neoprene weather stripping . The plug will be removable ( I know it will be heavy !! ) The landlord here requires access to the windows so I have to come up with a solution that is removable I think it will work well Any suggestions are appreciated !
Now THAT sounds more like a plug!!! :) It should work just fine. However, you can save yourself some money by dumping the MDF and replacing it with drywall. Mass is mass, and drywall is cheaper than MDF per kilogram of mass. It's also much easier to work with. Also, you probably don't need three layers: You'd probably find that two layers of drywall plus Green Glue (GG) will give you an excellent plug. Can you describe the construction of the WALL in which that window is located? It makes no sense to build a plug that is better than the wall, since the wall will be the weak link, and that's where the sound will come in and out. You only need to make your plug as good as the wall. So if your wall is standard single-layer drywall on each side of a single set of 2x4 studs, then anything more then 2 layers of drywall plus GG for your plug is going to be overkill, and wasted money. You could even leave out the GG and save more money there, since a normal wall isn't close to being as good as a wall with GG. If you could post some details of the wall itself, plus the rest of the room (ceiling, floor, doors, etc.), then we can probably give you better suggestions on how to build your plug. - Stuart -
chudforlife wrote:
Thank You Guys !!! As I have been thinking more about it I am going to go with a window plug that is going to be made with 2 sheets of 3/4 MDF with 1 sheet of 5/8 Sheet rock between .
I'd go with the mdf as well. Heavy though mdf may be, sheetrock is difficult to fasten to itself and this plug may not standup to the in the window out of the window, lean against the wall treatment that it will endure.
The Wall is an exterior wall . The out side is brick and the inside is a standard single layer drywall with insulation. These are the only windows facing the street . The space is on the second floor . The building is pretty old built in the early 1900s. The ceilings are 12 feet high, Oak floors, and the door is about 30 feet away. The noise Im trying to keep out is typical street noise. Nothing crazy. Im on a typical main street in a suburban town. Ive also looked into these http://www.climateseal.com http://www.magnetite.com http://www.acousticalsolutions.com/prod ... onlite.asp The plug seems like the best bet. It can be done for way less $$ I guess I need to get the idea out of my head that I need to keep the light from my windows !! Thanks !
Just looking at those web sites you linked to: 1) "Magnetite® Windows are constructed of a light-weight ..." That's as far as you need to go to know that it won't do much for sound isolation! "Light weight" means "low mass". For isolation you need LOTS of mass, so anthing that is "light weight" is not going to work as an acoustic isolator. Those "Magentite" inserts are meant for thermal applications, not acoustic. They should be good for keeping heat in or out (which is all that the manufacturer claims!), but they won't do much for sound. 2) "Acoustic Window Seals" Those will work, but you need to put thick glass in there. Forget the plexiglass. The claims made on that web page seem reasonable, but once again they don't give you real figures as to how much isolation the product will give you. Just go with the plug! Since it is removable, you can easily take it out if you want light or just to stare out the window for a while, then put it back in when you need isolation.
The out side is brick and the inside is a standard single layer drywall with insulation.
OK, so you should be getting an STC rating of around 40 or so with that kind of construction. Maybe 45 or even a bit more, depending on that brick, the air gap, and the insulation. So it makes no sense to aim for better much than 40 or so for your window plug. To me, it sounds like your plan with the drywall and/or MDF, added to the existing window, should put you in the ballpark. But what about the doors / ceiling? Your wall sounds decent, but if you have a door with gaps around it, then you need to fix that too, in addition to your window plug. Ditto the ceiling and roof. What are those made of? And how about the floor? Your total isolation is only as good as the weakest link. You can have a concrete bunker with 12 inch thick reinforced walls, but if you leave the door open, the isolation will be lousy... - Stuart -
Soundman2020 wrote:
the isolation will be lousy... - Stuart -
I am curious about that as well. Living next to a street, elevated...
The door is an entrance door across the room threw a small kitchen area . Its a 2 inch solid core door that is sealed pretty good . That door goes to my apt so I dont really have to worry about it. The room i use as my control room is my old living room that has a pretty high cathedral ceiling . The room is 25x 15. The ceiling is 12 feet that peaks to 15 feet . I have no neighbors above me or next to me . That room is treated with traps from Ready Traps . I have six of the Broadband Bass Traps and six High Frequency Absorbers . I also have 4 assorted traps of different sizes on stands that I use as necessary through out the room depending what Im working on. My real issue in this room is the outside street noise from the windows. After reading the posts (Thanks !!) Im going with the plugs ! My only question is how to seal them ? Im going with the 2x2 framing and making the plugs as a removable insert. The plug will go into the window sill against the new framing . If the window opening is 32x74 how much space do I need to get them in and out ? 1/2 inch ? Should I use the trunk rubber seal like Rod suggests for the doors as a seal for these plugs ? Thank for the help !
Hi I wanted to post the update on the window plugs I am going to build . What I decided on was to use 1 3/4 solid core doors cut down to fit the windows 32 x 74 . I have 3 windows to deal with . Mass will be added to the doors if needed . The window casings will be framed out with 2x2’s . All of the new framing will be caulked and sealed . There will be 8 inches of dead air space between the existing window and the new plug/door . I am also planing on using the type K weather stripping to create the best seal I can. One of the issues I ran into was the fire code here in town. I simply cannot plug all the windows but I am aloud to have a door that can be opened in case of a fire . Only one window has to have such a door . So one will have to be hinged and have a knob so it can open an close . I didn't want to do it this way but I dont really have an option. What do you guys think ? Any suggestions are appreciated . Thanks !