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Posts Tagged ‘soundproofing’

Soundproofing

February 1st, 2009

The case is great, but it doesn’t have sound-dampening panels or any features to actively reduce sound like many of the Antec cases.

I bought the bought the AcoustiPack LITE pack along with the case, which contains two sheets of the 2-layer self adhesive material. As the case isn’t that big, I didn’t need the ‘Ultimate’ pack.

Generally, the material was nice to work with. The adhesive backing is good, and you really can pull it up if you need to reposition. Which I did - it’s tricky to get the perfect fit first time. Much of it was in the measuring - I had to leave space for the case to close properly, while getting maximum coverage for sound absorption.

The hardest bit of the job was to lay the bottom piece, which goes under the drive bays. The screw holes for the drive bays are raised enough to get the AcoustiPack material underneath, but I had to make some incisions in order to get the raised bits through nicely. I also had to cut out a section to allow the flap over the front panel to move freely.

AcoustiPack preparation

AcoustiPack preparation

The self-adhesive backing was a bit fiddly as it kept ripping as you can see below. As AcoustiPack advertised though, if it’s not quite right you can pull it up and reposition if necessary, which it was.

Self adhesive...

Self adhesive...

I spent a while covering the power button assembly. While it may not have been necessary for noise, one problem I found when I plugged the power to the LED in (I wanted to see how it looked) was that the blue light spills through to the VFD window, so you can see through it. This doesn’t look very nice, so I made sure the gaps were filled. The same goes the other side so that the light doesn’t come out of the air vent in the case.

Case soundproofing (front)

Case soundproofing (front)

When it came to covering up some of the unnecessary vents, I didn’t want to leave the sticky backing exposed to the holes in the case. It’s just going to get dusty (the dust will stick) and won’t look very nice. What I did was to get some black paper, and sellotaped it to the case before sticking the AcoustiPack over it. As I didn’t have any, and didn’t want to waste printer ink, the black paper came courtesy of full-page ads with a black backgound in an old Top Gear magazine. Thanks, Vauxhall.

Roof soundproofing

Roof soundproofing

I tested the CPU fan against the open vent and it does make quite an airy whine though the holes. Seem like it was a good idea to cover up the vent which will be above the fan and let the air come in from the one next to it. The only trouble is that there’s only about 1mm clearance between the fan and the soundproofing - a bit more would have been nice I suppose that’s the trade-off with having such a slim case.

Another little thing I did was to get a spare bit of the AcoustiPack material, stuck it to some cardboard, and blu-tacked it to the bottom of my DVD drive. This will help to absorb any sound coming from the drive bay underneath it, and is removable for when I change the drive.

I’m not in a position to compare the noise before and after, as I did this before I’d even ordered many of the components, but it should be a good starting point for a silent computer. This SPCR review shows the difference that it can make - they say that while it isn’t ground-breaking, it does make enough of a difference to be worthwhile for the enthusiast. I’m pretty enthusiastic.

HTPC General , , , , ,

Airflow design

January 27th, 2009

I want a very quiet case. This means fans at low speed, for the most part. So, I know that airflow is going to be important. If it’s not coming in/out the right way, this could lead to a lot of heat build-up inside the case. Especially since the soundproofing material is probably not a very good thermal conductor (although I was unable to find any conclusive evidence either way).

One of the main things I’ve realised is that the power supply fan will be crucial to case airflow.

Looking at the design of the case, it has a vent in the floor for PSUs with a 120mm fan to suck air from underneath the case, which will cool the PSU before being blown out the back. Now, this set-up is fairly self contained and doesn’t help the rest of the airflow.

So I decided I need to use a PSU which sucks air from inside the case, and expels it out the back. This needs to be the primary output fan, simply because there isn’t much space in the case for any other fans in any useful position.

The case has two large vents in the roof, to serve the CPU fan, and it has four vents in the side. However, there are only screw holes to mount one 80mm fan by the front left vent. I’ll be replacing the supplied fan, as it’s pretty noisy.

So, cool air in the front left, and warm air out the rear back via the PSU. I don’t see a need for the rear left vent, so I’ll cover it up to reduce noise output. Same goes for the rear right, as the PSU will be in the way anyway (really, I don’t see the point having a vent there.

Although there’s no fan in front of it, I decided not to cover up the front right vent, because there will be hard drives near it, which will benefit from some cool air being drawn through by the PSU.
As for the top vents, I decided that I only needed one, and I covered the other to reduce noise output. I also chose to cover the one nearest the CPU fan. This sounds odd, but let me expiain: One of the main sources of noise is going to be the ‘whoosh’ of air turbulence through the holes in the vents. Roof vent 2 (see diagram) overlaps the fan on the CPU heatsink, and I think that the proximity, while offering good cooling, will lead to more noise. So, I’ve left ‘roof vent 1′ open, because I believe that the CPU fan will still be able to draw air through, and it removes the direct line of sight/sound to the CPU fan.

 

Airflow design

My airflow design for the Moneual 301

Here’s my little diagram. It shows the ‘naked’ case with the key heat producing components shown. The yellow blocks are the fans. Most of the arrows are the result of direct fan blowing, but the little ones are what I think will happen in that corner.

I’ve tried to think of most things but any tweaks or comments would be welcome.

Cooling, Hardware , , , ,