What to use to lower the computer noise in a wooden cabinet?

Question

I am looking for a good material for improving the sound-proofing my NAS which has 2x FANs of 120mm and 3-4 hard-drives. Most of the time the hardrives are those that are producing audible sounds, not the coolers.

Due to the lack of space I think that I cannot put material that has more than 1cm deep, as I will run out of space.

Please refrain from adding hints regarding reconfiguring the device or moving it to a different location, this question aims to address sound isolation of a small wooden (or particle board) like the one in the photo.

Answer 1

If most of the noise is coming from the hard drives, rather than the fans, then you need to dampen the vibrations from transferring from the hard drive enclosure to the furniture.

The vibrations could be made even louder by the fact that it's on a shelf supported on its ends only - this could cause the sound to be even louder if the hard drives vibrate at a frequency that lines up with the normal mode of the shelf.

I would recommend the following:

• See if the noise gets better by adding a support to the shelf that isn't just the ends. Try holding it with your hand, or propping it up with a board to see if that helps reduce the sound. If it does, look at adding support to the shelf.
• Add some velcro to each of the hard drive sleds
• Use rubber padded screws to attach the hard drive to the sled
• Put a rubber pad underneath the hard drive enclosure.

It may take some trial and error to figure out what helps and what doesn't, but the basic idea is to attenuate the transfer of the vibrations.

Or, you could just switch the drives to SSDs, or select drives that include built-in noise attenuation.

Answer 2

I am going to go against your advice and tell you the obvious - move it to another location. For a NAS to be in a location near where people watch the media and to complain about the noise from it is not very smart.

Everything that kponz has in his answer is right but will probably have very negligible difference in the sound of the hard drives or fans. Especially if you are 6 feet away. Really the only thing you can do to get rid of the noise is to insulate the area in sound dampeners which will surely affect air flow, which will make the hard disks run hotter, which will kick on the fans, and make it even noisier.

There is a reason why (small) companies put their servers in a closet or lab. They are noisy. I used to get dirty looks all the time when I was in dev and had a server under my desk. You are asking for advice here but unwilling to take the best and most obvious advice - move your NAS to a closet or room that you don't care about the sound.

Answer 3

You mentioned in a comment that the noise wasn't as bad before you put the NAS inside the cabinet. Given this, I suspect your cabinet is acting as kind of an echo chamber or megaphone, amplifying any sounds so they are much louder than they would be otherwise.

The solution is to put some sound-deadening material on the 4 inside sides of the box (though the bottom and top are probably the most important). You'll need to experiment a bit, but any foam or rubber like material should work. The thicker the better, but even a 5mm layer where the NAS is (and thicker elsewhere) would help.

Another solution would be to put a front on the cabinet. You'd want to put an intake fan, or a set of holes or mesh (with a filter), to allow for adequate airflow.