Author Topic: Soundproofing my computer CPU - Mass loaded vinyl + closed cell foam?  (Read 5130 times)

alex10294

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Hey,

I'm trying to build a REALLY quiet PC.  I want to eliminate high pitched fan noise AND low frequency vibrations from hard drives and fan vibrations.  I'm seen the advise to use SPP mat, but I don't think this stuff would have enough mass to stop enough sound to satisfy me.  I'm sure it'd work pretty well, but I'm looking for an extreme solution.

I'm considering using a 1lb/sqft mass loaded vinyl AND a 1/4 inch closed cell acoustic foam on the inside of the computer case (glued to the metal walls of the case with the foam on the inside) and more foam on the wall behind the fan output.   

The other option is to use 2 layers of 1/8 inch closed cell acoustic foam sandwiching some kind of deadener (maybe the same mass loaded vinyl) and glue that to the inside.

I'm also considering putting a baffle made of the same stuff to redirect the fan noise that comes out of the back downward.

Does anyone have a better solution than these, or have any reason that this wouldn't be a good idea?  My system runs very cool right now, so I'm not really concerned about heat buildup.  Also, there's plenty of space for both layers (my case is big).

Alex


Randy S

  • Guest
Re: Soundproofing my computer CPU - Mass loaded vinyl + closed cell foam?
« Reply #1 on: December 02, 2008, 06:40:02 PM »
Alex,

The SSP Mat would be the best to use in this case. 1/8" MLV has a 26 STC rating, and SSP mat @ 1" has a 25 STC rating. The difference being is the SSP Mat also has a NRC Rating of 0.30 which is absorption.
http://www.soundproofing.org/sales/prices.html

If you want to increase this I would recommend using Noxudol applied to the metal case before you adhere the foam mat, this will reduce the resonance of the metal casing.  Adding MLV to this will add mass but remember sound will take the path of least resistance so any gaps or leaks is where the sound will come out of and making the case air tight is not an option.
http://www.soundproofing.org/sales/liquid.html

The baffle system should be lined with the SSP Mat and you need to add multiple 90 degree turns to acheive a compounded reduction of sound and keep proper air flow.






alex10294

  • Guest
Re: Soundproofing my computer CPU - Mass loaded vinyl + closed cell foam?
« Reply #2 on: December 04, 2008, 01:58:24 PM »
Thanks for the advice.  I'm glad I asked before I ordered.  I guess I was stuck in the line of thinking where I was trying to prevent the sound from getting out.  Now that you say it, it makes sense that you really can't in a computer case.  I like the idea of multiple bends in the baffle too.  I'll have to get out my modeling tools and make one. 

It's really nice that you respond to all these even when it's not going to make you a lot of money (PC case is a pretty small order).

Thanks,
Alex

 

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