[spartan777]

I've been studying how to silence my PC. After installing the quietest fans, the next thing to do is to muffle the air intake/exhausts. I'm going to make my own from some tubing and foam. What materials absorb the higher-frequency whine of a fan and the upper mid to high frequency of a hard drive? What foam or sheets of material can I use to line the inside of the muffler? I was planning on making a muffler in the shape of on 90 degree pipe elbow attached to a 180 degree elbow. I'll attach a diagram of it.

 

[Kawai_man]

You can also line the case with mass loaded vinyl, although this might affect the temperature

 

[Dalamar]

You could always put your pc in another room and run the cables through the wall...
 

 

[earerror]

Quote:

You could always put your pc in another room and run the cables through the wall...
 

lol.....or you can use a notebook instead. 
 
Seriously, your project seems interesting. Post some pics when you are done with it. 

 

[DaveBSC]

I use AcoustiPack sheets inside my case, which would also probably work for what you're doing.

 

[spartan777]

I'm aware that people use vinyl or acoustipack to line their cases. However, I'm not interested in doing that. I needed to determine if it was the case walls or the air intake/exhausts that were causing more noise. I put pillows and blankets over the front, back and top of my case, which is where all the intake/exhausts are. The result was silence- even though I've never put anything like acoustipack on the sides. At least for me, and I suspect most people, the main cause of noise it noise seeping out through the holes of the case.
 
I did finally order some acoustipack and I'll see if that works well for this. Besides that though, I was thinking PVC piping would be the easiest to use, but I think it echoes noise pretty well. It might be irrelevant when I cover it in acoustipack, but can anyone think of something more sound-absorbant?

 

[spartan777]

By the way, I just bought a new case and its in the mail now. On my old case the entire front was one big air intake (I have 2 120mm and 1 92mm fan), this caused a lot of noise. However in my new case, the air intake is on the bottom of the case. This will hopefully allow the noise from the intake fans to be absorbed by whatever is beneath my case, wood in my situation. My project will be to create mufflers for the rear and maybe the top exhausts. I ordered enough acoustipack to cover my whole case, and I have a decent microphone (Blue Yeti) so I'm going to try to determine what reduces how much sound in the most scientific way I can. Hopefully everyone can use my info.
 
my old case:
 
http://www.newegg.com/Product/Product.aspx?Item=N82E16811133154
 
my future case:
 
http://www.amazon.com/Corsair-Obsidian-Aluminum-Enthusiast-CC700D/dp/B003AM8QH4/ref=sr_1_2?ie=UTF8&s=electronics&qid=1280738753&sr =8-2

 

[DaveBSC]

Check out some of the guides on Silent PC Review for help. Intakes and exhausts are usually where the noise is concentrated. It make sense if you think about it. If you run a fan in free air, its loud. Cover it completely in a sealed box and you'll get rid of most of the noise. Cut a hole in the box, and the noise will come through that hole. The trick is to use a combination of damping, silent fans like Noctuas, a silent power supply, etc. I'm to the point now where my Lian Li X1000 is pretty much inaudible from 2 feet.