Car horns honking, “L” trains zooming by, wind howling through trees, the incessant orchestra of crickets, unrepentant roommates — one of these (or a multitude of other ambient noises) could be a disturbance to your project or bedroom studio. You could try to block out the invasive outdoor noise in all manner of ways, from installing double doors and walls to the crude but effective draping of blankets over windows. However, it's easy to forget how much of a living, breathing — and therefore noise-producing — space the inside of a studio can be. Computer fans, humming amps, creaking furniture and floors can all add up to an unpure listening environment and “interesting” (often bad) recordings. To remedy these situations, here's a list of generally inexpensive or free things you can do to clean up your studio's undesirable self-noise.
No matter how cool it is to have a studio mascot cat, if Fuzzy or Mittens purrs, meows, leaps up on top of monitors, clings to your lap, annoys your guests or performs any other typical cat behaviors that might affect a microphone's position, he or she doesn't belong in the studio during recording. That also applies to your dogs, hamsters, rabbits and other critters. At least you'll keep fur out of your gear — an asset when it's time to sell it on eBay. Anything that can't reliably remain completely still during tracking is a potential hazard. Next, if you live in a hot or cold climate, air conditioners and heaters with fans should be temporarily turned off whenever possible, and definitely during any microphone recordings. Shut windows during tracking to avoid outside noise getting in. And if your studio occupies a building with roommates, family members or any other humans that could potentially knock on the door, set some ground rules, such as “no knocking if this door is closed,” or hang a sign that says “Quiet: Session in Progress!” Even if it's never happened before, the one time it does during a killer vocal take, those sounds will ring in your ears forever. Plan ahead; your recordings are worth it.
Often the single noisiest thing in today's studios (aside from the occupants) is a computer. Unfortunately, that is especially true during tracking, since hard drives and fans are spinning and whirring away. Aside from isolating your microphones in another room altogether (which can be a good option), a great solution is to purchase a computer isolation box. Like a vocal iso-booth in reverse, these boxes are designed to keep noise inside, away from your microphones. If you go this route, however, make certain that your computer has working fans installed inside, otherwise you risk overheating — a very bad thing. You can build your own box if you're handy, but make sure you know what you're doing. Good iso-boxes also have fans built-in to ensure cool air flow; do your homework before breaking out the power saw and hammer. For some commercially available isolation boxes, try the Isobox at www.custom-consoles.com or the Silentmaxx at www.quietpc.com, and also look for the Silent Drive internal hard drive enclosure at www.directron.com.
If an iso-box is impractical, as in the case of a laptop, at the very least keep your mics as far away from the computer as possible during recording. To isolate vocals, if you don't already own an acoustically treated vocal iso-booth, try recording in a closet. Make sure to position several layers of hanging clothes on both sides of the mics, and also try hanging some on the front and back walls if possible. As contrived as that may seem, clothes closets can be very effective at dampening noise and creating an acoustically dead environment to retain your vocal or instrument purity. Laying down carpeting both inside the closet and out — especially if you have creaky, old hardwood floors — can do wonders for avoiding ruined recordings. That doesn't necessarily mean an expensive wall-to-wall job; simple area rugs will do just fine (and in fact can be better because you can move them around as needed or take them up if you want to brighten the sound of certain takes). Another poor-man's trick for sound absorption is to hang a thick tapestry on the ceiling. Tack just the four corners and the middle; not only will that provide a nonflat, porous surface to assist in sound diffusion, but it also can spice up your studio's vibe.
Hardwood floors aren't the only hazard to combination control/tracking rooms. If your office chairs are creaky, either replace them or try dropping a little oil in the joints if it seems feasible. I've unfortunately found through experience that it's particularly disturbing to capture a perfect vocal take, only to listen back and discover that it's blemished somewhere in the middle by chair noise. Cat meows or people whispering can sometimes be included in final mixes as “natural sounding” or “interesting” elements. It's harder to explain away the sound of a squeaking chair. Next, if you own your home or studio space, consider installing double-paned windows. That is especially important if your room is proximate to a major road or freeway. If you live in a rental or installing new windows is too impractical or costly, putting curtains up can help eliminate sound intrusion from outside the studio. Because windows are a highly sound reflective, covering them with curtains will go a long way toward diffusing the sound from within as well. Finally, there's paint. If putting sound absorption material or even tapestries on the walls renders your studio too “dead” for your taste, you can experiment with painting the walls with flat paint instead of gloss or semi-gloss. While the effects of that may be subtle, painting in flat paint will help kill the noise.