Confusing case

Hi!
I'd like to deal with weird problem. Recently I used to have my comp running without case. It had to have it running this way, but it's not important.
I wanted to put whole thing back to my case. The difference comparing to site is that I have that nasty grill on top cut, BeQuiet PSU + fans connected to PSU running around 5.5-6v. My CPU radiator is Zalman-style with speed set to minimum. HDD with rack lies on folded cloth to minimize noise and vibration.

Why is it so confusing?
My comp produced less noise when it was just in parts on desk. After puttting to case it's more noisy and worse - when I close side panel it's even louder.

That PSU has temp controlled fan, so it's obvious that temp increases - fan speed increases, but it has still almost no airflow. Fans on back are in brackets, fan on top and PSU are screwed with rubber pads between part and case.

I haven't got anything that would measure noise, but it sounds like louder. The more I close case, the louder it seems to be. So my question would be - wtf )) and what could I do to eliminate as much noise as possible (with minimum cost - lets say max $10-15)

Of course your PC is louder enclosed in a case.
You are now experiencing two results of equipment confined in a small space...direct vibration (HDD) and reflected noise (everything else).

You can isolate the HDD from the main case chassis either with manufactured solutions (ala the Zalman heatpipe enclosure) or a homemade method (zip ties are popular and several pretty sophisticated-hence, less ghetto appearing- solutions have shown up here in the forums).

After that, you need to disrupt the radiated sound from fans and the HDD.
Lining the case interior with foam (egg crate design is particularly effective) will help muffle noise from the case interior...a more effective (albeit more complicated) solution involves creating baffled channels to direct airflow in and out of the case.

Look here for more info.

Big thanks.
I'll check these zip ties, when only I'll find what they are (english isn't my strong side). And that noise dampening you presented looks logical - I have no noise dampers in case, only ghetto-style hdd vibration damping

Zip ties...

Oh thanks.
And I found such thing:

These are for car audio, but as you see some use it for computer.
They're rather cheap (around $1.5 for piece - 250x500mm - around 10x20 inches). Would it work? I can't ask guy who has this comp as he sells it.

//EDIT//
Found that too:

5-25mm height, with 100x130cm it's $10

Intuitively I would guess that the second option ( the egg crate design) would yield the best results, but a combination of the two might be even better.
The acoustimat (first pic) would definitely help on your sidepanels if they curently suffer from vibration.

Real world cooling is largely dealing with the effects of placing the equipment in a case. You've got lots of ventilation when it's on the bench, and it's hard to match that when it's shut up in a box.

There are only really two things necessary to cure this, beyond the vibration dampening and mass addition discussed above. Firstly is you need adequate exhaust fan capacity, I recommned two 92mm fans, one 120mm fan, or ideally, should the case permit, two 120mm fans. The other thing you need is an unrestriced inlet, preferbly in the lower front of the case. It does not need a fan in it. It just needs to breathe freely. What the rear exhaust fan or fans expel will pass though an open inlet.

Most cases have innadequate exhaust fan area, bad location, and/or a restricitve inlet. Fixing the design problems is required to get you back to the place you would be if case designers faced any reasonable standards of job performance.

1st - thanks for reply
It's not shown on photos correctly, but as it's server case, when door is open, you can see more holes than metal. Even with door closed air in restriction from front is minimal. I've also got two "PCI slot plugs" under VGA removed for better VGA cooling.

Just now my air flow is crazy. Upper fan in, 2 rear out, dual fan PSU out. It's because now my comp stays near heater (behind comp), but I might just move it to other place and change combination.

My 3 fans in case came with case itself. I got this case pretty cheap, as used for <$10, so didn't look for fans more exepnsive than case itself At 12V noise is far from acceptable range. 1st - it's Codegend - manufacturer doesn't care users ears. 2nd - it's server case - so was designed to stay out of people range.
Earlier I used my custom ghetto controller for the se fans to limit speed, now I use PSU fan-only lines - running 5.7v now. They don't push much air on this voltage and don't seem to be noisy with open case. So theory about inadequate air in/out and resonance meets reality here. Anyway they'll probably get replaced. I've seen some 80mm fan discussions (I don't want to mod this case too much).
Unfortunatly Mechatronic fans are out of my range. Noone here has heard about them. Sanyo Denkis are avaible but for insane price (for example 120mm are $40-50 for one). It look I have to use Arctic fans (pro TC for <$3 each, ver 3 for $6) with mod to manual control, as they push almost no air as intake fans.


So, thank you for all advices. Now I know what to focus on when silencing my comp. I've been seriously tired last days and couldn't find what is wrong with my comp, now I can act. Thanks again.

What is that? rubber?

i think its dynomat or whatever you call it

its sound insulation/absorbtion material

thegreek said:

What is that? rubber?

Click to expand...

Don't know what its called, but I got 1.5m^2 roll of it next to my computer. Stops vibration and isolates noise. And yes, its very rubberlike, but better acoustic qualities. Its seld adhering to boot.

So we'll give it a try. Looks like I'm 10$ off for dynomat and same with foam.
I wasn't assured with it, but as you confirm it's good, I'm definietly going to check it.