Another PC noise trick

dblbass · Post by **dblbass** » Thu Apr 04, 2002 11:16 pm

My DAW PC produced a lot of rattles and buzzes, which were amplified by the case (a tall tower with steel sides). I will add some foam or other deadening material to the inside of the side panels, as suggested elsewhere here, but in fact, I have the side panels off fequently as I am often in there fiddling.

For audio tracking, close it up, but otherwise, the huming and rattling are bothersome. I thried this:

I cut little circles of bicycle tire inner tube and drilled holes through the centers. Using longer than normal mounting screws,
I put a a little rubber circle between the side of each drive (CD and HDD) and the PC case mounting bracket. I also put little plastic washers under the screw heads, and thus pretty much eliminated most of the metal-to-metal contact between the drives and the case. Same for the power supply/fan unit.

This made quite a difference, so much that I wished I had done a little before/after db metering to measure the improvement.

Also, on the front panel, the little plastic covers in my case covering unused dives bays were a source of buzzes. A couple of tiny squirts of silicon caulking (like for small bathroom countertop repairs) into the gaps quieted them right down. It only took a few drops and I'm sure I'll be able to prise them free easliy enough if I need to later.

algorhythm · Post by **algorhythm** » Fri Apr 05, 2002 6:09 am

only problem is that by eliminating the metal-metal contact on drives, the heat dissipating surface area is greatly reduced, which means that your hard drive will tend to run hotter, and therefore not last as long (think of your whole case as a heat sink). An appropriately placed fan or ductwork can eliminate this problem. Perhaps do a before/after temperature test on the HDD?

Round1 · Post by **Round1** » Fri Apr 05, 2002 6:12 am

Good tips.......better still (but more costly) is this case.....www.calmpc.com
I've just ordered one for my control room, I'll post my findings when I get it set up and running (hopefully next weekend...around the 13th)

Neutron · Post by **Neutron** » Fri Apr 05, 2002 12:17 pm

On 2002-04-05 06:09, algorhythm wrote:
only problem is that by eliminating the metal-metal contact on drives, the heat dissipating surface area is greatly reduced, which means that your hard drive will tend to run hotter, and therefore not last as long (think of your whole case as a heat sink). An appropriately placed fan or ductwork can eliminate this problem. Perhaps do a before/after temperature test on the HDD?

hahah yes a nice powerful FAN ought to solve the overheating caused by QUIETING your computer

seriously though, you might try isolating the whole drive cage from the rest of the case instead, then the drive cage is still heatsinking the drives, but the vibration is kept from the case and its drum like side panels.

at0m · Post by **at0m** » Fri Apr 05, 2002 7:55 pm

Here's what my friend did for ultimate silent studio:

He moved his pc's to the other side of the wall (into next room), made some holes for the wires (if needed some extension cords for mouse etc).

Only disadvantage: he has to go to the other room to swap cd's.

dblbass · Post by **dblbass** » Fri Apr 05, 2002 8:41 pm

A good point Algorhythm, but I did actually think about this (though I didn't take any measurement)

Just feeling by hand before making this change, I found very little heat on the outside of the drive rack brackets a small distance above and below where the drives are mounted. By doing this I no doubt lost some bracket surface area for heat dispersion, though I suspect the finned top plates on the HDDs are the most important part.

Life's all tradeoffs, I guess. Before this, sometimes the drives would set the whole bloody case into a nasty, loud LFO reso thing (whah - whah - whah - whah), and I'd have to press my hand to the top of the case to dampen it down. That's gone now.

atomic - maybe you friend should use a SCSI CDRW. SCSI works over a couple of metres, doesn't it?

Anyway, for the cheapo bedroom, obsessed amateur studio like mine, this trick is work a couple of hours, provided cooling isn't compromised too much.

[ This Message was edited by: dblbass on 2002-04-05 20:52 ]

at0m · Post by **at0m** » Fri Apr 05, 2002 9:33 pm

Here's a topic about cooling.

How I cooled and silenced my computer:

-I glued some (5mm, but heavy) rubber/foam to the case, about everywhere but one the vent holes

-I took insulation tape and put it on the edges where the case hits the frame/box.
-Made a sandwich for my drives, w 2 thick aluminum plates, which stick out the disks. Then I filled up the sandwich sides w thicker foam.
-On the center frame -between my motherboard and power supply on the rear and between cd/hd bay on front- I put a plate. Made a hole in the plate to insert a fan. This causes a strong flow from the bottom to the top of the pc. The fan is not close to air in/outlet which causes less noise again. If I had not put the extra fan in, my pc would run too hot with all the isolation foam.

About SCSI drives: my experience is that those are quite noisy. Here's my friend's site (the one who moved his pc to another room for less noise).

at0mic.

[ This Message was edited by: at0mic on 2002-04-07 01:46 ]

Post by **garyb** » Sun Apr 07, 2002 1:32 am

http://www.norenproducts.com/

John Henric · Post by **John Henric** » Tue Apr 09, 2002 10:14 am

Check out this hd suspension/damping solution. Too simple or what? I think it can be replicated quite easily by a 'layman'.

http://www.whynoi.se/shop/product.asp?intProdID=48

http://www.whynoi.se/shop/productsByCat ... E4ngningar

Immanuel · Post by **Immanuel** » Tue Apr 09, 2002 10:33 am

I have that thing - i realy does reduce vibration imensely

Immanuel

orbita · Post by **orbita** » Wed Apr 24, 2002 3:19 pm

I made a post here about noise that may be of interest

http://www.planetz.com/forums/viewtopic ... forum=19&0

lavoll · Post by **lavoll** » Fri May 31, 2002 1:55 am

http://www.quietpc.com/powersnooze.php

i installed that stuff in my pc to quiet it.
the temperature is the same as before, but the quieting wasnt all that noticeable. It did reduce the side-panels singing along with the hard disks completely, but the fan noise level seems to be the same still.

(i should just get a quieter cpu fan maybe)

i have also thought about buying a 2nd set of those mats and use them in a iso-box that i can build myself.

mgranger · Post by **mgranger** » Fri May 31, 2002 4:47 am

I have fitted my PC out with components from Quit PC.

I have installed:
Silent power supply
one 8" rear fan
P4 (478) silent heatsink and fan
two silent drives for both HD's

I also lined the whole case with accoustic dampening material normally used for cars with big stereo's

The noise is now minimal, I can't even hear the computer at all over the road noise (which is minimal).

I totally recomend doing this to your computer.

Laterz

spacef · Post by **spacef** » Fri May 31, 2002 4:56 am

What should be done (by some genius) is to place a ultrahigh fidelity mic that takes the sound of the noisy PC, then refeed it over some kind of studio monitor, in the correct phase to null the noise. Phase opposition for real time sound cancellation.
It's science fiction (eventhough it is used in long courrier planes) but i'm interested in anything in that field if you have links...
just an idea, i know it's not very doable. .

Myself I use the "put it in another room" solution : cheapest, very eficient in home studios. It's also used in studios who can afford expensive boxes to isolate the noises.

[ This Message was edited by: spacef on 2002-05-31 05:59 ]

Neutron · Post by **Neutron** » Fri May 31, 2002 6:33 am

It will not work very well because the sound sources are in different places. so the phase of the waves at each frequency has to be constantly calculated. even then if you move your head 6 inches some frequencies will get twice as loud because of standing waves.and reflections all over the room.

someone had the idea for outside noise though. get a "sound bug" and put it on the window. have a mic outside the window.

window moves in opposite direction to incoming sound and cancels some of it out.

works better with a window because the sound is all coming from the same direction.

spacef · Post by **spacef** » Fri May 31, 2002 6:46 am

that's why i've chosen to put the computer in the kitchen

For the speakers that cancel noise, i think it's possible with a "super surround" (hundreds of speakers everywhere in your room). (imagine all your walls, floor, cellars is a speaker).

Curently it's absolutely true that it works only as you said, but may be that's not due to a mathematical impossibility to do it, but to the current sound input/output technology which makes this not doable.

I think latency is also a problem, at least nowadays.

The computer in the kitchen is better for the moment...

[ This Message was edited by: spacef on 2002-05-31 08:02 ]

spacef · Post by **spacef** » Fri May 31, 2002 8:18 am

Thinking of it, the phase sends should be around the computer, not in the room, which makes it compulsory to build a box anyway.
The wall stuff etc is for outside noise isolation.

remixme · Post by **remixme** » Fri May 31, 2002 9:02 am

That kind of phase cancellation is not science fiction, apart from being used in courier planes, high end luxury cars also use the same technique.

[ This Message was edited by: remixme on 2002-05-31 11:31 ]

spacef · Post by **spacef** » Fri May 31, 2002 11:44 am

RemixMe: That's very interesting for me and some of my sound researches. If you ever find a link please feel free to post (i don't know what to look for in web-searches). Thanks for your post, for me it shows that this technique is improving and finds new applications.

remixme · Post by **remixme** » Fri May 31, 2002 12:37 pm

mmm, I think manufactures try to keep that one close to their chests, they must spend millions into R&D into quieter car interiors.
So its not readily available infomation, if you know any people in the car design trade, have a chat to them.