Quiet P4 Project

Steve Rosenthal · Post by **Steve Rosenthal** » Tue May 18, 2004 10:49 pm

What started out to be an under-$600-TigerDirect-special has turned into my first silencing project, and quite unexpectedly, my home DAW. In the process creating quiet, I've learned an important lesson: If you're planning on giving your computer the silent treatment, come to SPCR first.

The case is a Just4PC cheapie, but it's taken pretty well to the mods so far. MB is a Soyo P4VGA with VIA chipset, P4 2.8GHz and 1GB DDR2700 RAM. I've got two Seagate Cudas (40GB for system and 120GB for audio), a 52x CD burner, nVidia AGP, SoundBlaster 4.1 PCI, and Adaptec 4300 PCI FireWire HBA.

PSU is Nexus NX-3500, HS/f is Nexus PHT-3600, intake and exhaust are Nexus 80mm. (Gee, how'd I wind up all Nexus?)

The case is dampened with a combination of Acoustipack Deluxe and CompUSA cheap stuff.

I began with IDE ribbon cables, then switched to round, then (on inspiration from Ralf Hutter's cablegami) back to ribbon again.

The intake fan is on the bottom of the case and snaps into a plastic retainer...

Originally, the retainer had a restrictive guard over the fan, so I snipped it.

On the underside of the case, I used the trusty $10 CompUSA case nibbler to remove the restrictive stamped grille (pic is blurry)...

A little duct tape and a piece of furnace filter over the intake (looks lame, flows well)...

Same cutaway treatment for the exhaust (duct tape over rear vent to keep the airflow front-to-back)...

Gratuitous shot of HS/f, PSU, and exhaust...

The computer lives in a desk with built-in shelf...

Once again inspired by a thread on SPCR, I cut a vent hole in the shelf for the bottom intake and lined it with a grommet (blurry pic)...

Note: the white part visible in the hole is the intake fan filter.

The "final" step will be a bezel I'm making this weekend which will fit around the computer and "seal" the front of the shelf area. This should block the relections I'm getting off of the wall in back of the computer and render the thing almost inaudible.

Some quick numbers:

Ambient noise in room (computer off) = 30.5dba
With computer on = 36.7dba

Most of the energy is at 25Hz, 32Hz, 125Hz, and a little at 315Hz. I get some beating between the intake and exhaust fans, but mostly I hear some air movement and the really annoying buzz from my CRT.

Temps are:
CPU Idle = 44C
Chassis Idle = 29C
HDs Idle = 32C

CPU Load = 45-46C
Chassis = 32C
HDs = 36C

--Steve

Post by **Ralf Hutter** » Wed May 19, 2004 5:38 am

Good for you! A nice basic setup + some light tweaking and good engineering and you've got yourself a pretty quiet, powerful system. I give it "two thumbs up".

Steve Rosenthal · Post by **Steve Rosenthal** » Wed May 19, 2004 10:25 am

Thanks, Ralf. This is fun, and a dang site cheaper than modding cars!

--Steve

Steve Rosenthal · Post by **Steve Rosenthal** » Mon May 24, 2004 8:23 pm

Here are the results of my first swag at a bezel for the computer desk. I consider this a "working prototype".

It's 3/4" particle board in three front pieces: two sides and the top piece with contact paper for a finished wood-grain look. There are two support legs as well. I left a 1/4" gap around the inside of the cutout to allow for some wiggle room with the computer. That gap is lined with 1/4" foam weatherstripping, so it's sealed but flexible.

The bezel makes a big difference, but I still need to make some actual SPL measurements.

Next version will be a one-piece cutout using either finish grade ply or a veneered piece of shelving. I think I'll still back that with the particle board for additional density.

--Steve[/img]