There are a variety of vendors that offer solutions- some work better than others. I've spent some time quieting down my standalone HDR, and I have a rack-mount DAW on order, so I've been looking into this stuff.
Cooling fans can often be addressed. There are several companies that manufacture reduced-noise power supply units, and the claim is that they can help. A possible vendor is
http://www.quietpc.com/
if you are in the UK (which I'm not). They provide good ideas, though, and food for futher searches.
Some of the specialist DAW vendors also stock reduced-noise components. They might be worth a call for upgrade purposes:
http://www.nwccomputers.com/
http://www.soundchaser.com/pcdaw/
http://www.audiocomputing.com/
http://www.wavedigital.com/
If I recall correctly, NWC Computers is an importer of the SilentPC hardware to North America. They probably aren't the only one, but this will give you some ideas for further searches. In short: call and ask for ideas.
My DAW is being built to my specs by Soundchaser, and will have all the quiet-operation components that they stock. We'll see how well it works when it gets here...
In terms of silencing your existing box without upgrading components: mass is your friend. Rather than *pad* the box, which can cut down airflow if not done with great care, consider adding mass and damping to the case to reduce transmission of noise from inside to outside. I used Dynamat on my HDR. This is the self-adhesive tar/fiber damping material that is typically used by car stereo installers to damp automotive body panel resonances. This stuff works like a *charm*. It is thin, easily worked, and adds both mass and damping to sheetmetal panels. A layer of this bonded to the inside of your case's cover could kill any resonances and provide you with a remarkable improvement quieting with little cost. It's dependent on the type of noise, though: it is most effective against mechanically-transmitted whines and wheezes, rather than airflow turbulence noise.
After that, see if you can safely reduce the speed of any fans. The higher the fan speeds, the greater the turbulence noise. CPU and hard drive cooling fans are often the cuplrits here: they are typically teeny little 40mm or 50mm fans that are screaming their brains out trying to move air. In the case of my HDR, I replaced a microscopic 40mm fan with a 50mm fan operating at half-speed (running from a 9v supply provided by sticking a couple of diodes in series with the +12v...), and reduced the fan noise by a good, solid 12dB while actually improving the airflow. In the case of the machine in front of me, I was able to remove the fan on the CPU heatsink altogether, and still keep reasonable operating temps at the die (because of the overall airflow design of the box). This can be pretty serious engineering, though, and you need to be careful when mucking with cooling to avoid making expensive Krispy Kritters.
Adding mass and tuning the fan speeds may or may not be enough. Hard drives whine and vibrate, and there's not much you can do about them other than perhaps rubbermount them and add some massive panels between you and them. The final weapon is to buy or build a hushbox, and I suspect that I'll end up going that route eventually. This is a cabinet with gasketed doors and its own low-noise cooling system. Stick the noisy stuff in there, close the door, and let the room get quiet. The bad news about this approach, of course, is that it costs a *sizable* wad of bucks. But if the machine is intractably noisy and can't be relocated out of the room, or if you have more than one obnoxius machine, this is a (rather painful!) option.
http://www.raxxess.com/isoraxx.htm
http://www.custom-consoles.com/isobox.html
http://www.custom-consoles.com/isomac.html
http://www.middleatlantic.com/studio/saccess/ecisorack.htm
I haven't found any pat, one-size-fits-all solutions in my searches. However, I've had some success using combinations of the techniques above. Hope that helps. and good luck...
Emeric, Slackmaster2k, you other good PC wrenches: any other advice? I don't know much about home PCs yet, but they aren't that different from the engineering workstations I've been munging on for the last decade or so...
[Edited by skippy on 01-18-2001 at 07:12]
