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Strong bass causing buzzing behind the wall

I've got a spot in my new listening room (in the basement) where there is a drywall wrap around some hvac ducting along one of the side walls at the ceiling. The drywall is installed over thin aluminum framing. When I play music with strong bass (e.g. Jennifer Warnes "Way Down Deep"), I can hear buzzing in the wall. I set up REW to generate a sine wave around 50Hz and I can easily cause the buzzing. 

The good news is that pushing on the drywall in a particular place will cause the buzzing to stop. So I'm trying to figure out the best way to fix this. I was thinking of drilling a small hole and spraying some expanding foam insulation. Something like this: 

https://www.homedepot.com/p/GREAT-STUFF-16-oz-Big-Gap-Filler-Insulating-Foam-Sealant-Quick-Stop-Straw-99053938/207050533

But I'm not confident that this will stop whatever is vibrating, and once this stuff is in, it might be harder to deal with the issue another way. 

Any ideas? Thanks.
128x128jaytor
millercarbon's avatar
millercarbon
12,531 posts
 
I am a little concerned that pumping too much of the foam through a small hole might cause the drywall to bulge.


Not a problem. The way that stuff works it comes out goopy and bubbly and expands. It doesn't push, just spreads out in all directions, path of least resistance kind of thing. You'd have to pump a whole can in there to have a problem. Maybe not even then.

The more likely problem is it goes in and by gravity or whatever just doesn't fill in the right spot. But you're really only out the cost of a can so what's to lose? Worth a shot.
jetter
3,033 posts
 
213runnin
Yes, I did exaggerate a bit, on purpose to make a point to someone who may not have used the product. I would hate to see a tiny problem replaced with a big one. I had very expensive Marvin Ultimate windows installed where the installers used the expanding foam as a bit of insulation on two of the windows and to this day the windows are a bear to open and close. Yes, I have used it myself.

I do disagree with Millercarbon's benign description of the product just above.
213runnin
914 posts
 
Maybe they just did a poor job of installing, I really doubt that the foam could bulge 2x4 studs.
audiozenology
362 posts
 
"It can probably bend studs, its that strong."   .... is what was stated. I don't know if that is true or not. Unlikely, because the drywall will give first, and it will, if the foam has no where else to expand.
jetter
3,033 posts
 
I agree with you audiozenology.  Really no need to analyze my comments any further as wl all have made OP aware that this stuff expands like all get out and can wreck "stuff" (yes most likely drywall or sheetrock name depending on the part of the country you live) if not used carefully.

213runnin, it was used between the stud and the wood frame of the window.  Per Marvin professionals it is not an uncommon problem that the foam can bend the wood frame of the window which is much thinner than 2x4.
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