By now, we're all aware of the benefits of lower-cost, higher-quality pro audio technology. Cheaper, faster, better-sounding gear lets engineers exit the controlled acoustic environments of “from the ground up” purpose-built recording studios to work literally anywhere they desire. However, creating your own audio environment can be an exercise in futility without accurate acoustic surroundings. Sadly, our gear-centric industry often leaves acoustic treatment as a last priority. On the bright side, treatment options abound to control and optimize your studio acoustics. And with a little room assessment and product research, it's easy to find the right tools for your space.
Because we're talking about optimizing existing spaces rather than building from the ground up, the most important products to consider are surface treatments to manage your working space's sonic energy. These products fall into three basic categories: isolation, diffusion and absorption. The goal in using these treatment techniques is to create an acoustically pleasing sonic space with a relatively flat frequency response and little room-influenced coloration.
Acoustic Sciences Corporation TubeTraps
Note: These products are generally not useful for soundproofing. In pre-existing structures or rooms, acoustic isolation can often be a challenge, as the best acoustically contained structures are usually purpose-built with effective use of air gaps (open spaces within the walls) and dense materials. Improvements such as floating floors, rooms within rooms and additional insulating materials can be used for improved isolation, but leakage — both in and out of a studio — is difficult to eliminate, especially with low-frequency energy.
Products often used for isolation include pads, baffles, wedges and various insulators composed of a wide variety of materials. Other isolation products — used to keep components from each other within the studio — include monitor isolation wedges, instrument/amplifier pads and many types of “go-betweens,” otherwise known as gobos. These isolators usually provide a combination of absorption and diffusion, and can be set up in different configurations for specific applications.
Having a good frequency balance within a room is a must for accurate recording and monitoring, and getting the right acoustic results can be difficult in environments with hard (aka reflective) parallel surfaces such as walls, ceilings and floors. To combat sound-degrading effects on such environments — which include reflection-caused standing waves, flutter echoes and a generally disproportionate representation of present frequencies — a combination of diffusors and absorbers can be used.
Diffusion products break up flat surfaces to reflect sound at various angles, which help to dissipate standing waves and flutter echo without removing acoustic energy from a given space. Absorption products reflect only a portion of the acoustic energy striking them, attenuating specific frequencies while reducing reverberation. (This value is expressed as a Noise Reduction Coefficient; see sidebar on page 42 for details.) Together, effective use of diffusion, isolation and absorption tools, along with experimentation and regular analysis of frequency response, can make even the most acoustically offensive room usable.
If you're thinking of putting together your own studio or want to upgrade an existing room, there are more treatment options than ever. To help get you started, below is a comprehensive collection of acoustic materials companies, with their areas of product expertise and explanations of their most notable creations.
ACOUSTIC TREATMENT MANUFACTURERS
Established by acoustic engineer/physicist Arthur Noxon in 1984, Acoustic Sciences Corporation (www.tubetrap.com) is an acoustic research, design and product development company. It is well-known for its patented TubeTrap, a pressure-zone, corner-loaded bass trap voiced with a treble-range diffusor panel. Other notable ASC products include the compact Cube Tower, the acoustically adjustable StudioTrap and the SubTrap, a solution for an increasingly subwoofer-dominated audio world.
Known for its high-quality noise control enclosures, windows and doors, Acoustic Systems (www.acousticsystems.com) also offers a “hybrid line” of modular sound-isolating rooms, a possible solution for engineers unable to commit to a particular locale for an extended period of time. Acoustic Systems' modular studios include isolated floors and silenced ventilation with options of non-parallel walls, canted windows, bass traps and various other treatments.
Virginia-based manufacturer Acoustics First (www.acousticsfirst.com) offers a large array of acoustic materials, including sound absorbers, barriers, diffusors and bass traps made of materials such as polyurethane and Class-1 Melamine foams, Fiberglas, wood, plastic and metal. Of particular interest is its Transfusor, a transparent diffusor panel created to fit standard 2×2-foot fluorescent light fixtures.
ClearSonic SORBER Panel
In addition to providing a wealth of acoustic treatment knowledge on its Website, Auralex Acoustics (www.auralex.com) offers numerous acoustical product solutions, including foam, diffusors, bass traps, construction components and various other notable products. Of special interest to engineers on the go is the MAX-Wall portable treatment system, an expandable absorbent wall with various dimension, window and mounting options. The ISO series offers improved isolation for monitors (MoPAD), drums (HoverDeck), amplifiers (GRAMMA) and mics (AuralXpanders).
ClearSonic (www.clearsonic.com) — makers of the ClearSonic Panel used primarily for drum set isolation — offers the SORBER S2 baffle, a 1.6-inch-thick fabric-covered Fiberglas wall treatment device. Built for easy portability, SORBER panels are light and easily mountable on a variety of surfaces. When custom-configured with ClearSonic Panels, SORBERS can be used to create well-balanced isolation spaces, booths and even rooms.
ESR (www.zainea.com) offers the Roundffusor1, a combination diffusor/low-frequency absorber made of hard polystyrene. According to ESR, using the Roundfussor1 in a standard 9-15 — piece group drastically reduces a room's overall reverberation time. Much theory and explanation of the Roundffusor1's performance can be found on ESR's Website.
Golden Acoustics Golden Section Broadband diffusor
Golden Acoustics' (www.goldenacoustics.com) Golden Section Broadband diffusors are visually intriguing acoustic panels that are available in a variety of dimensions for wall and ceiling applications. Golden Acoustics also makes a full Golden Section tuning column in custom lengths of up to 24 feet. Flat-mount Golden Section options include the full-broadband ceiling panel, center ceiling/triple-corner panel, end ceiling/double-corner panel, full-wall broadband panel and a wall panel quarter-section inlay.
Gretch-Ken Industries Inc. (www.soundsuckers.com) — the makers of modular SoundSuckers isolation booths — offers foams, bass traps, ceiling tiles, baffles and fabric-covered absorbent panels, all available for purchase via its Website. While not exactly an acoustic treatment product, Gretch-Ken's super-hip Egg-Pod Chairs would make a very nice addition to any studio's client lounge.
Designer of absorber panels and bass traps, Hill Acoustic Design (www.hillacousticdesign.com) can emblazon its acoustic treatment products with any image — studio name, logo, etc. — or unique designs from its large digital image library. All Hill Acoustic Design products are custom; for more information, log on to the company's site.
Illbruck (www.illbruck-sonex.com) — makers of Sonex acoustic panels — provides a full line of acoustic ceiling tiles, wall panels and baffles in a wide variety of patterns. For instance, its CONTOUR ceiling tiles are now available in 14 different patterns, such as Crosspoint, Mosaic, Matrix 2 and Allusion. Illbruck products are made with the trademarked Willtec foam, which the company says offers excellent absorptive control and impressive fire ratings.
Markertek (www.markertek.com) may be best known as one of America's largest pro audio manufacturers, but it also manufactures a full line of soundproofing and acoustic treatment products under the MarkerFoam brand. MarkerFoam products include ceiling and wall tiles, acoustic pads and baffles, acoustic sealant products, portable isolation booths and acoustic blankets.
MBI Products Company's (www.mbiproducts.com) Cloud-Lite Baffle is the industry's original fully encapsulated absorbent baffle and is available in finishes of PVC, nylon, polyester, vinyl and weather-resistant fabrics. Other MBI offerings include the Lapendary Panel — used mainly in live indoor concert venues — and the Colorsonix absorbent and decorative wall panel, which is available in a wide range of dimensions, thicknesses and colors.
MSR StudioPanel (www.studio-panel.com) offers pre-engineered acoustic treatment kits that vary based on a room's size. StudioPanel Acoustic Treatment Systems include a collection of diffusors, absorbers, bass traps and various other panels with specific mounting directions, effectively making complex placement issues simpler for the end-user. Notable StudioPanel components include the Bazorber slotted low-frequency absorber, CloudPanel fabric-covered ceiling panel and the SpringTrap, a ported corner bass trap for ultra-low frequencies.
It's all in the name: Netwell Noise Control (www.controlnoise.com) makes an extensive range of noise control and acoustic design products, including polyurethane acoustic foam panels, bass traps, ceiling tiles, wall coverings and fabrics, even isolation tools such as duct-work wrapping materials. Netwell's comprehensive Website provides solutions to acoustic issues in interesting categories such as garage band, basement band, recording studio and ceiling/floor noise bleed.
Primacoustic's (www.primacoustic.com) wide array of studio acoustic solutions include bass traps and diffusors, wall and ceiling absorber systems, Primafoam foam absorber components and the IsoPad, a monitor acoustic isolator. Two all-inclusive product solutions — Studio In a Box and the Freeport GoBo — offer a complete set of tools to treat a single room and a mobile studio environment, respectively.
Real Traps offers many bass trap products.
RealTraps (www.realtraps.com) have quickly become a leading provider of broadband absorption solutions with its complete line of affordable and portable bass trap products. MiniTraps, MondoTraps, MicroTraps, GoboTraps and the new aesthetically unobtrusive SoffitTraps all offer various and impressive absorptive benefits. As an added perk, RealTraps offers detailed acoustic theory and product application information on its Website.
RPG Diffusor Systems (www.rpginc.com) makes attractive and functional diffusion systems for a wide array of environments, including live venues, recording studios, residences and commercial facilities. RPG specializes in intricate custom diffusors comprising a variety of materials and for mounting in a variety of areas.
Dealer Silent Source (www.silentsource.com) sells a wide variety of foams, barriers, baffles, bass traps, diffusors and much more, but also markets two of its own signature products. Hushfoam panels are very absorbent open-cell polyurethane foam wedges. WhisperWedge is a 2×4-foot flat-foam absorber that is available in thicknesses from two to four inches. WhisperWedge is available in a variety of colors and urethane and Class-1 Melamine consistencies.
StudioPanel diagram from Sound Control Room Inc.
Steven Klein's Sound Control Room Inc. (www.soundcontrolroom.com) is not only a licensed reseller of StudioPanel all-inclusive acoustic solutions and Tecnifoam acoustic products, but the firm also created the Saturn polycyndrical diffusor, an acoustic treatment tool resembling a giant aspirin for use on walls and ceilings. Other custom SCR products include its three-panel absorbent booth and Instant Studio, a full-frequency mobile control panel.
Taytrix (www.taytrix.com) offers clients a simple and innovative way to acoustically treat a recording environment: the StackIt GoBo System. Available in three styles and two colors, StackIt GoBos feature multiple layers of insulation covered with fabric on both sides and measure 46×15×30 inches. Both Plexiglas and natural maple panels are available for the StackIt product line. Taytrix also offers studio furniture, studio wiring, and design and build services.
Vibrant Technologies (www.vibrantech.com), a multifaceted audio products company, offers the aesthetically pleasing DF-24 diffusor, a molded-plastic diffusion panel. The DF-24 fits perfectly into a standard 2×2-foot ceiling grid, can easily be wall-mounted, is paintable and installs easily.
Wenger Corporation (www.wengercorp.com) has long treated audio-centric spaces for acoustic energy problems using its range of absorber and diffusor panels. Other Wenger products include ceiling clouds and portable risers, the latter of which the company claims eases loudness dissipation.
Strother Bullins is a North Carolina — based freelance writer specializing in the pro audio, music and entertainment industries.
CATALYST RECORDING'S ACOUSTIC EVOLUTION
Years of Fine-Tuning North Carolina Studio
Rob Tavaglione owns and operates Catalyst Recording, a busy music studio located several minutes south of downtown Charlotte, N.C. Building Catalyst in the 1,000-square-foot, half-subterranean basement of a 1960s brick ranch home has proven to be money well spent for Tavaglione. Since 1994, Tavaglione has hosted a steady stream of local and regional musicians, keeping his self-designed residential facility teeming with a hip and varied client base, while letting him take advantage of an abundance of equipment and experience gained during his lengthy tenure as a local musician and engineer.
Creating a great-sounding and affordable facility was an early challenge for Tavaglione. He already possessed the necessary gear and studio know-how, so having a suitable working environment was the final step to launch his own business.
Catalyst Recording features a variety of surface treatments.
“Acoustic treatment is an emotional and very important topic for many of us,” Tavaglione says. “On the surface, the subject of acoustic treatment materials may seem dry, but the fears we face while trying to deal with our acoustic issues can be a ‘hot button’ issue.”
The acoustic issues Tavaglione faced during his studio's 11-year acoustic evolution may ring familiar with other D.I.Y. studio owner/designers. “With basement studios, low-frequency waves don't pass through your walls and to the outside world; it's all contained,” he explains. “Because of that, I had a number of standing waves. I was also getting diminished frequencies from nodes where waves were canceling each other out and there was a lot of early reflections because of the cinderblock walls and cement foundation. The space was quite reflective, and I was getting a lack of definition in imaging. Things were kind of blurry.”
Tavaglione insists that addressing problems via acoustic analysis, treatment and materials research, and experimentation led to clear acoustic solutions. “I used sine waves, swept them across the spectrum and found my problem areas, particularly with issues of bass,” he says. “I found a buildup at about 80 Hz — which is pretty common — and another around 50 Hz. I also found that there was a cancellation up into a higher bass frequency around 110 Hz.”
After repositioning his subwoofer to a central position (in front of the mix position) and crossing it over at 80 Hz (to decrease directionality), Tavaglione employed a variety of surface treatments to address acoustic discrepancies. “On the walls, I used a 4-inch-thick absorbent foams — 2-foot by 4-foot — and covered them with tapestries for a softer look,” he continues. “That cleaned up the early reflections nicely, helping with imaging clarity. For my bass issues, I used some of the corner-mounted foam bass traps in the control and isolation rooms. Those cleared up bottom-end muddiness in the iso room.”
Rob Tavaglione spent 11 years upgrading Catalyst's environment.
photos: Angela Linker
Other solutions included foam monitor isolators and a custom console cover. “In today's automated environment, where so much is done in the computer, I don't need to touch the console all the time during mixes anymore,” says Tavaglione. “The cover's absorbent cloth reduces some of the high and high/mid frequencies coming off the console, which really cleared up my imaging.”
Tavaglione says that a facility's acoustic treatment is often a journey rather than a destination, but one that should always produce a sonic improvement. “I don't think that it's ever going to end for me,” he admits. “I'll just keep on tweaking and improving.”
— Strother Bullins
SLEUTHING THE SPECS
When you shop for acoustic treatments, you'll notice different specs than those for, say, a power amp. After fire safety ratings, the most important specs for acoustic materials define noise absorption and transmission. Two specs you'll often encounter are:
NRC, or Noise Reduction Coefficient, represents how much sound energy is absorbed by a given material. The NRC is actually an average of absorption values at various center frequencies between 125 and 4k Hz (rather than an absorption value across the entire bandwidth). For example, a concrete wall has an NRC of 0.01 at 128 Hz and 0.035 at 4k, but an overall NRC of 0.023.
STC, or Sound Transmission Class, specifies the amount of sound (in decibels) blocked by a barrier and generally applies to dense, hard materials or walls. STC is an average of transmission loss values taken from center frequencies across a wide bandwidth. Some examples: Brick walls often have STCs in the 50 range, while a ¼-inch plate-glass window may have an STC of 30.
Remember that just as stated frequency response hardly defines a microphone, the specs alone do not make or break the product; these numbers are meant to be used as guidelines, as they are usually the results of testing performed in control environments that do not take into consideration the variables inherent in a typical studio space. These ratings are averages of performance values across different frequencies, and those values can vary in different ranges, depending on the material.
Click here to download chart in PDF format listing acoustic treatment materials manufacturers and detailed information on products offered.
Eddie Ciletti shares his tips for managing low frequencies in any room (spare bedrooms included), as well as a list of acoustic solutions. Click here to read more.
Randy Alberts offers ways to tackle soundproofing challenges with turnkey acoustic treatment packages. Click here for the feature.