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Discussion Starter · #1 ·
How do you block sound from a projector fan? I have a ceiling mounted projector and would like to block the fan noise from the projector because I'm right underneath it. I don't want to construct a complicated hush box or anything, but rather just need a 2ftX2ft piece of "something" placed underneath it to block the sound from it. Any suggestions as to the best "something"?
 

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Ceiling tile with a layer of cork, or a layer of Dynamat.


Sound blocking without weight is non-trivial ChaCha.


mark
 

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True MDF is fairly heavy, but as rogo hinted at its the weight that is related to density and hence sound absorbtion. With some decent mounting screws into a ceiling stud it shouldn't cause any problems.


I'm not aware of any other cheap common material that is as effective as MDF.


Yes Markito he could go the Panny, but he'd then have to fork out more cash of vaseline to smear over the lens to mask the smoothscreen artifacts ;)
 

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I'm in the same boat as ChaCha -- (you've got an X-1, right ?) -- anyway, I'd suggest preparing a durable _mount_ for whatever you decide to try, and then try a few different things.


as far as noise absorbtion goes, I would think that mass is more important for absorbing lower frequency noise.


fan noise is higher frequency and I'd think that mitigating reflection of that fan noise is at least as important as the absorbing material itself.


so. I also have an X1 directly above my head, and between bookcases at that -- which backs up to a wall. a 3-sided tunnel, only open at the front.


I'll probably use lightweight plywood mounted horizontally below the projector, w/ some foam above that to kill reflected fan noise.


for appearance, I'll do a nice funish on the underside, and put a lip on the front to hide the foam ...


some of that noise comes out the front of the projector and I don't know yet what to do w/ that ...


ymmv,


Mark
 

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Discussion Starter · #8 ·
Yes, I have an X1 Mpilon. Maybe a sheet of styrofoam would be the way to go placed on top of a piece of mdf. I'm not sure I understand what makes for good sound absorbing properties since some of you say it is the density of the material, and yet professional sound absorbtion stuff supposedly is made of bubbles which makes it not dense at all. Wassup?
 

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Absorbing foam in studios is for stopping sound from reflecting of hard surfaces causing excess reverb; the sound is spread up. Dense materials are for stopping sound pass though the surface to the outside world.
 

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I have a JVC G1000 and let me tell you these things need help. I purchased some poly-fill like what is commonly used in speakers ,some garden variety fiberglass from Home Depot and quarter inch steel mesh. This is how mufflers are made. It can be tuned by the density of the wadding and length. Perhaps I will get some of it finished this weekend and can compare with my Rat Shack Db meter.
 

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Yes, I was comparing outside world to those sitting beneath. Dense materials stop sound penetration, fluffy absorbent materials stop sound reflection. Most studios have a combination of both. In your case I'd suggest stopping sound penetration is the best solution (although it may reflect of the MDF and bounce onto the roof and back to you; perhaps some cloth or foam on the top side would be good too.
 

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Discussion Starter · #13 ·
Sounds like dense material is the way to go for sound blockage. Anybody know of some material that is both dense and light? ...or is this wishful thinking? What type of wood is the densest?
 

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My local Home Depot has round MDF circles with white laminate that I might end up putting directly under my L300U to deflect noise.


I've noticed a slight increase in fan noise from my unit since I went from my temp projector stand (ladder with phone books and boxes to get the right height) to my chief mount with pipe from HD.


Figured that would probably be easiest and look the best.
 

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If you want to go the sound blocking way. You can try homasote.

It is sold in 4'X8' sheets like sheet rock. I have built several recording studios and we use it to deaden walls and cut down on sound. Sound can travel well through solid. The best way to cut down on sound is a solid-airspace-solid with the 2 sides not touching. I don't think that will really apply to your application. Maybe you can cut 2 pieces and place small pieces of rubber or neoprene in between. It may come out to about 2" thick

Homasote is pretty cheap and extremely light weight. You can cut it, but do it outdoors it makes a mess. I would second the opinion of putting some acoustic foam above the projector if the ceiling is fairly close. The foam just redirects the sound. It will eventually get to you, but you may be able to lower the volume enough. Seems like a lot of trouble.

Good Luck
 

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Here is a link to Homasote
click here

It is cheap and light weight.

You can buy it at Home Depot or most home improvement or building stores. It is sold in 4' X 8' sheets the size of drywall. It is slightly brown in color.


It will cut sound as well as or better than MDF or any other dense building material. Sound can and does travel through solids. They resonate.

I still don't know if putting a shelf or piece of anything under the projector will help much so I am curious to hear the results.


I have tried most of them and actually have built sound proof rooms and recording studios including one in my house. It works.

This would also work very well in dedicated home theater rooms or in apartments that are joined. It can be placed on the wall and covered in wall paper or felt etc. Painting may not be desired look as you can see the texture through it. Feel like painting cardboard. You could also place another layer of sheet rock on top and crank up your subs a little louder.
 
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