A Kit Of Inexpensive Acoustic Treatment Solutions
By Jon Chappell
Senior Editor, Harmony Central
Auralex Acoustics is a company devoted to creating acoustic treatment materials and devices, making all manner of absorbers, diffusors, sound barriers, and complete room-treatment systems. But for any recording professional including the home studio recordist on a budget, Auralex can also help you achieve more professional results right away and without turning your studio into a construction site.
Auralex's Audio Engineers Pack is a well-chosen collection of portable, inexpensive, and specially designed soundproofing tools that treat the most common problem scenarios plaguing small studios. If you suffer from such acoustic ailments as mic bleed, hardware rumble, acoustic coupling, and structure-borne resonance, the AEP provides the means to start stamping out these audio gremlins quickly and easily. The AEP is comprised of five components that everyone can use as acoustic treatments—for microphones, mic and drum stands, amps, and monitors.
A Word About Foam
All the components in the AEP are made largely of foam, but you should know that not all foams are created equal. The Xpander pieces (which are used for mitigating bleed on mics) are made of Auralex's StudioFoam®, a proprietary open-cell acoustic foam that doesn't break down or crumble, and contains no melamine or CFC's (and so is very eco-friendly). The GRAMMA AE, PlatFeet®, and MoPADs® use a denser closed-cell foam that is designed for isolation and decoupling applications.
Five Degrees Of Separation
There are five components in the AEP, covering microphones, floor-dwelling amps and monitors, and tabletop or shelf-dwelling monitors. Following are brief descriptions of the pieces.
Designed to go between the floor and a bass or guitar amplifier, or a subwoofer, the GRAMMA® AE is a heavy 15"-square square base of dense fiberboard encased in fabric and topped with foam pieces that securely cradle the amp or speaker cab. Two outside foam blocks provide support while an inner, recessed accordion-shaped piece makes up the center. This construction allows for symmetrical support, irregular shapes, and air flow—all desirable aspects to breaking up potential acoustic-coupling enablers.
MoPADS® (for Monitor Pads, get it?) are slender, modular wedges that go under your studio monitors, which most likely sit on a hard surface—like a desktop, shelf, or speaker stand. You dedicate two of the main wedges to support one monitor, varying the distance between the wedges for the width of your particular monitor. Each main wedge has a corresponding auxiliary wedge that you can use to effect a tilt. Creating an advantageous tilt is especially important in smaller nearfield monitors where the tweeters are very directional. Using these auxiliary wedges, you can create tilts of -4°, -8°, 0° (flat), +4°, and +8°.
For treating mics when they're on their stands, Auralex contributes two devices. Trap-Xpanders go around the snare drum and hi-hat mics to eliminate bleed and other off-axis influences between these two closely placed, yet independent sources. Tri-Expanders are larger triangular pieces that fit around any mic shaft, stand, or even cable. Use two of these on any mic, and position them accordingly so that they block any unwanted bleed and filter undesirable overtones.
PlatFeet® go under mic and drum stands, between the bottom of the stand poles and the floor. Especially good for isolating cymbal stands. Like the GRAMMA AE, PlatFeet also absorb structural-borne resonance.
If you have an acoustic drum kit, you know that reducing ring, cross-mic bleed, and structure-borne resonance are constant battles. I found I could place the Xpander sets in any position and they would hold firm to the mics and stands, even when the music started. The foam slits are strong enough to hold their positions and grip the various components securely, but elastic enough to accommodate different shapes for variously sized mic housings, clips, shafts, booms, and so on. I recorded my house trap set with and without the Trap-Xpanders, and A/B'ed the end results. I could definitely hear the difference, with Xpander recordings exhibiting more isolation, and therefore yielding better control over the mix with the Xpanders in place than without. In fact, I didn't even have to record: With a friend playing drums and me wearing headphones, I could hear the difference through the board as soon as I slipped the Trap-Xpanders on. Over in the "vocal corner" (can't afford a whole booth!), the Tri-Xpanders significantly improved the sound, and they were so quick and easy to configure.
I had similarly positive results with the GRAMMA AE on my Crate bass amp. Because I have a wooden floor, low-frequency rumble is often an issue, preventing me from getting too loud without creating wolf tones, or simply have to go through machinations of elevating and isolating the amp from the floor—none of them as fast or as elegant as simply inserting the GRAMMA AE. With the PlatFeet under-foot of my vocal-mic tripod stand, the rumble was reduced to almost nil. And nothing pleased me more than to finally have an elegant solution for my Tannoy nearfield monitors. The single-digit degree tilt affords different positions for optimum listening angles, which savvy clients and visitors will note and appreciate. The MoPADS work simply and effectively, and it doesn't hurt to see the Auralex logo peeking out from underneath your nearfields, either, as it lets people know you've taken special care in isolating your monitors. And they're so much better-looking than mouse pads!
While you may eventually get around to soundproofing your walls or dropping that ceiling, you can't afford not to reduce bleed and decouple your monitors, amps, and mic stands from the floor right now. And even if your particular setup can't make immediate use of all five components in the Pack, you will definitely need them all at some point. For quick and effective treatment of the most common problems plaguing your acoustic environment, go with Auralex's Acoustic Engineer Pack—and make yourself look professional in the process.