Silence In A Control Room

By Greg Simmons

There’s nothing worse than trying to do audio work with a personal computer whirring away beside you. The continual background noise masks important detail and makes your ear/brain system work harder as it tries to extract the signal. The harder your ear/brain system works the sooner you get hearing fatigue, and that means you do less work and get less enjoyment from it. It’s the aural equivalent of watching a movie while wearing sunglasses - you can’t see the proper picture, and eventually you get sore eyes and give up.

Many engineers try to convince themselves, and their clients, that they can listen through the noise. I’m sorry, but this simply isn’t so (grab any decent reference on psychoacoustics and look up ‘masking’). You will hear a certain amount of audio through the noise, but you won’t hear all of it, and it won’t be in the right proportions - some sounds will be more apparent than others. Any audio judgments made under such monitoring conditions will be dubious to say the least. If you honestly believe you can listen through the noise, you’re fooling yourself and ripping off your clients.

The cheapest cooling systems use fans, and the cheapest fans are noisy fans! So, most personal computers are sold with two, three or even four noisy fans. The power supply has a fan, the CPU has a fan, the VGA card may have a fan, and sometimes the enclosure has a fan. For marginally more money, you can invest in low noise fans and a low noise power supply.

What about the enclosure? Those pressed-and-folded boxes are mechanically coupled to all the fans and hard drives, and their flimsy side panels make excellent diaphragms that radiate the fan and hard drive noise into your working environment. You can tackle this problem in four ways. Firstly, bond acoustic absorption mats (e.g. PAX.mate) on the inside of all the panels to damp the vibrations. Secondly, use rubber isolation mounts for your hard drives and fans to minimize mechanical coupling to the enclosure (low noise enclosure/PSU combinations, such as the Antec Sonata, come supplied with such fittings). Thirdly, place the enclosure on a soft foam block to further absorb the vibration. Fourthly, ensure the enclosure is not in physical contact with any walls or furnishings to prevent the vibrations being transmitted elsewhere and radiated into your studio.

Hard disks are another source of noise, so start by choosing a model that’s known to be quiet, and mount it in one of the handful of sound absorbing systems available for this purpose.

I turned my back on noise a few months ago by investing in a silent personal computer that I’ve christened ‘The Arp’. The improved low-noise monitoring environment has made a startling difference to the quality of my work. My balancing, editing and processing decisions are far more assured, and the results consistently translate better into the real world. I will never again pay for time in any studio where the monitoring environment is shared with an audible personal computer and neither should you - there’s no excuse for it, and it’s as stupid as wearing sunglasses while watching a movie.