Author Topic: Installed a magnetseal window. Losing effectiveness?  (Read 2625 times)

kwhubby

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Installed a magnetseal window. Losing effectiveness?
« on: June 06, 2014, 09:23:06 PM »
Hello,
Renting near a loud expressway, being unable to sleep, I installed a magnet seal window. At first this provided amazing results, but about a month later now I am annoyed by sound again, particularly around or below 200hz (loud engines). I can't decide if this is in my head or if something has changed.
 I used 1/4" plexiglass for a opening 4x5ft. After seeing that gap size should improve reduction, I extended the gap by about 1" using brick mold around the outside of the window. The gap is 4 or 5 inches.
I sealed the brick mold and metal framing using "Kwik Seal Kitchen & Bath Adhesive Caulk" I did not use an acoustic or silicone caulk. I'm wondering if an increase in firmness is coupling the low frequencies into the walls or causing the plexiglass to radiate sound. To the original wall I first applied tape to hopefully reduce damage from the caulking when I may need to remove it.

Am I simply becoming more sensitive to noise? Unfortunately I did not take sound measurements when I first installed it to determine if something is changing, I will probably take measurements soon.
Is there a way to further improve mid-low frequency performance? I have been thinking about re-installing using acoustic caulk, using a dampening membrane between plexiglass and magnet or metal and wood, adding mass to plexiglass.

Thanks!
 

Randy S

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Re: Installed a magnetseal window. Losing effectiveness?
« Reply #1 on: June 07, 2014, 05:52:41 PM »
"Am I simply becoming more sensitive to noise? " Yes this is possible.
The only way to improve the system would be to get thicker acrylic 3/8"
all systems based on reduction are on a curve, better reductions at the higher frequencies and lower reductions at the lower frequencies.
At the lower end of the range you need to get more mass and greater air gaps. the air gap you have is ideal so the only thing that would improve the system is more mass.

And always check your seals, they can wear out over time.
Randy Sieg

Super Soundproofing Co
www.soundproofing.org
888-942-7723
Ph. 760-752-3030
Fax.760-752-3040

kwhubby

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Re: Installed a magnetseal window. Losing effectiveness?
« Reply #2 on: June 10, 2014, 12:12:17 AM »
Thanks for the reply. I figured my sensitivity is the biggest factor.
The cost of 3/8" over 1/4" got very expensive, I don't imagine I will buy it at this point.

 I know that various soundproofing related constructions use "green glue" and the like to assure acoustic performance and reduce flanking.  I'm worried about flanking and coupling between the structures, particularly as I noticed everything become more rigid after drying for a number of days (metal strips have ~1/8" of caulk between them and wall). Can we be assured that the type of glue, or flanking won't be a significant factor in this type of window treatment? Assuming everything is air-tite, is it better to have a firm or a more isolated attachment to the regular sheetrock-wood wall?

On another thought, if I also used a window plug or MLV curtains, wouldn't I get further reductions?

Thanks!



Randy S

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Re: Installed a magnetseal window. Losing effectiveness?
« Reply #3 on: June 10, 2014, 03:40:09 PM »
Green glue with a new layer of drywall on the existing walls will reduce flanking noise.

a MLV curtain would give you a bit more reduction if you could seal it to the wall. might not look great but would improve the reduction.

Also the caulking you used could be getting to firm and might be contributing to the problems..remove the caulking clean well...when you re apply the "acoustical caulk" take a string and wrap it around the acrylic before caulking and leave a small piece exposed, caulk the acrylic and when it is time to remove simply pull the string and it will cut the caulk with ease.
Randy Sieg

Super Soundproofing Co
www.soundproofing.org
888-942-7723
Ph. 760-752-3030
Fax.760-752-3040

 

anything