Reducing Ambient Noise In Computer-based Studios

You probably don't realise how noisy your computer studio is until you turn everything off and enjoy the silence. PAUL D LEHRMAN explains how you can arrange your setup to reduce noise and restore peace to your working environment.

Computers have fans, hard disk drives, removables, and various other peripherals that produce noise, both constant and irregular. For the majority of computer users, such as business people, scientists, or even graphic designers, this noise is relatively innocuous, a minor annoyance that is far outweighed by the convenience of having the on/off switch, the reset button, and access to floppy drives, CD‑ROMs, and other media close at hand. But for musicians, this is not the case. For a musician, having a high ambient sound level in a music studio is like an artist working in a room where the walls are painted fluorescent paisley. No matter whether you're recording tracks, editing sounds, or mixing, a high noise level is sooner or later going to interfere seriously with what you're hearing, and cause your work to suffer.

Remotely Interesting

Unlike mainframe computers or professional video decks, which are usually in a machine room separate from their operators' primary work area, most personal computers aren't designed to be anywhere but right on your desktop. Remote operation rarely figures in the thought processes of personal computer designers. The cables that generally come with personal computers — monitor, SCSI, and keyboard — are all short, and if you ask a computer retailer for a longer cable, you'll probably be met with a blank stare. And don't forget that there's a limitation on cable length built into one of the most important protocols of the personal computer world: SCSI (which, remember, stands for Small Computer Systems Interface). The SCSI specification itself limits the total length of a SCSI chain — that is, all the cables connecting all the devices in the chain, including any internal drives — to six metres, or about 19.5 feet. Not very far.

With a little ingenuity, some of these limitations can be overcome. First things first: let's move the computer out of the studio, and then we'll figure out how to hook it up. If you have another room adjacent to your control room, think about stashing the computer over there. Put the computer close to the common wall (although not necessarily right against the wall, because that might allow vibration to come through), and then punch a hole in the wall big enough for all of the cables to go through.

A more convenient solution is a cupboard or closet right in the control room — either one already there, or one you build. The most important thing to keep in mind when stashing a computer in a closet, however, is to make sure it gets plenty of fresh air. So instead of simply shutting the equipment away, cut away about six or eight inches at the very bottom and top of the door, to create a kind of chimney. Cover the gaps with foam from an air‑conditioner filter to reduce the noise level and keep dust away from the machinery. Build a shelf or use a small table to get the computer off the floor, but don't make it so big that it cuts off the vertical air circulation. Put the computer and other hardware on some more foam to cut down on vibration transmission. You may even want to put in a small low‑noise fan in the closet to draw air upwards. Mount it on a wall (not the door) above the computer. To access removables, you can simply open the closet door, or else build in a small door right in front of the drive opening(s). Use Velcro or a wooden hasp to hold it closed — a metal latch might vibrate.

Cable Buy!

OK — now that it's safely out of earshot, how do we control this gear?

• SERIAL STUFF: We need cables for keyboards and mice, monitors, and serial devices. Serial cables for a Mac or PC are no problem — these can be pretty much as long as you like, assuming that you start with decent‑quality cables.
• MAKING THE SWITCH: If you need to change cables a lot, like between a MIDI interface and a modem or printer, and the computer's new location has made this difficult, bring a cable from the serial port out to an external switch mounted in a convenient place, and connect your peripherals to the switch.
• MAC FACTS: Keyboard cables for a PC are easy to extend, but on the Mac things are a little more complicated. The Mac's Apple Desktop bus (ADB), which connects the keyboard, the mouse, a trackball or pad, some modems, and the occasional hardware dongle to the computer, uses a special round connector with four pins and a rectangular 'key', to make sure it is oriented correctly. Although ADB runs can be quite long, dedicated cables greater than six feet are hard to find, and they tend to be expensive.

If you go to a video store, however, you will find perfectly good ADB cables, of all sorts of lengths, at quite reasonable prices. That's because ADB connectors are identical to connectors used for S‑VHS video. Your local Tandy won't have them, but a dealer who caters for video professionals should have S‑VHS cables in abundance, in lengths of anywhere from five to 50 feet — or even longer.

• SCSI LOGIC: As far as SCSI cables are concerned, if all your various drives are crammed into the closet with your computer, length is not an issue. But you should use the shortest cables you can get away with, not just to keep down the clutter but also to prevent the weight and odd angle‑forces caused by longer cables from straining the connectors. If you have devices stacked on top of each other, you may be able to use rigid 'C' connectors, which literally clamp in place behind two SCSI devices, and form a solid connection while keeping the signal path length down to the absolute minimum.

Sometimes, however, you need to run SCSI cables to devices that are located some distance from each other. For example, you might have a sampler that you want to use with the CD‑ROM or Zip drives that are attached to your computer, or you'd like to exchange samples between it and the computer, over SMDI. If the cable you need is going to be any greater than six feet long, get the very best quality you can find. Make sure the cable is at least double‑shielded, with both copper braid and aluminum foil protecting the conductors. A cheaper cable may seem to work, but it's the nature of SCSI problems that they come and go, and a cable that is marginal may be OK one day and throw a tantrum the next.

• THE TERMINATORS: If you have a complicated SCSI setup, or if you move devices in and out of your system often, you might want to invest in some of the sophisticated analyser/terminators that are now available. These can alert you to problems with termination (and automatically fix them), voltage drops, and impedance conflicts. Another useful device is a 'hot swapper', which lets you switch SCSI devices on a chain without powering the whole system down.
• STAYING SINGLE: Use a single long cable to do longer runs, rather than stringing shorter cables together; the connectors themselves contribute to signal loss, so the fewer of them the better. High‑quality 12‑foot male‑to‑male and male‑to‑female cables shouldn't be hard to find, although be prepared to spend some money.

Screen Gems

Finally we come to monitors, an area where it seems that nobody knows nothin'. I discovered this unfortunate fact in a recent redesign of my studio — it took about two months for me to piece together all of the solutions. Granted, my needs were rather special: I have an office and a studio in separate rooms, each with a monitor (one 17‑inch VGA, one 19‑inch BNC) and keyboard, but connected to a single computer (which lives in a closet between them). But even if I were just trying to get my monitor away from my computer, I would have come up against the same problems.

If you just stick an extension onto a monitor cable, whether it's Mac‑style (which uses a DB‑15 connector, with15 pins in two rows) or VGA (DB‑15HD, which arranges the pins in three rows), chances are you will have to deal with signal loss, line noise, interference, and other factors that will seriously degrade the picture quality. This can result in washed‑out colour or 'ghosts'. While the former is ugly, the latter can cause serious eye‑strain if you stare at them for too long, and staring at a computer screen for too long is something we all do a lot of the time. If your monitor is an energy‑saving model, you may find that the signal level drops so low that the monitor sometimes won't even kick out of sleep mode.

For a musician, having a high ambient sound level in a music studio is like an artist working in a room where the walls are painted fluorescent paisley.

Once again, using top‑quality cables will help. 'Double‑shielded' cables may not be good enough; 'individually shielded', in which each of the internal cable pairs has its own shield, is what you want. As with SCSI, using one long cable is far better than adding extensions — the connectors themselves serve as entry points for interference.

Many monitors, particularly those made by Sony or NEC, use multiple BNC connectors. They need to be hooked up to your computer with a 'breakout' cable, which splits the signal from the VGA or Mac video connector into three, four, or five individual components: Red, Green, Blue, and possibly Horizontal and Vertical sync. Each component has its own shielded connector, and there again is the key to making long cable runs work: individually shielded cable. But rather than use an extension for the DB‑15 or DB‑15HD, use as short a 15‑conductor cable as you can, putting the breakout as close to the computer as possible. For the rest of the run, use multiple coaxial cables with BNC connectors on each end. It's not as neat as using a single cable, but your eyes will thank you: runs of 50 feet or more with no picture degradation are not a problem. Again, a good video supply house will have the BNC cables in the lengths you need.

Finally, if you have to deal with really long monitor cable runs — or multiple monitors, such as in my studio — you should look into a video booster/distribution amplifier. This device raises the signal level, so that it can easily overcome all sorts of noise problems, and thus run great distances. Various configurations are available, in both Mac and VGA, with up to eight outputs. One warning: if you have a short video cable from an older Mac, in the days before Apple supplied monitors with permanently attached cables, and you're tempted to use it between your computer and a video amplifier, don't. Those older cables did not have all the pins wired, and they won't work with any monitor or peripheral that needs all of the pins, which most do today.

Quiet Life?

Good luck in getting your noise level down below a dull roar. Perhaps someday, low noise levels will be a common design goal (and specs that feature noise levels will be available), and we can put our computers back on our desktops. For now, hopefully these hints will let you keep the noise in the closet, where it belongs.