Jun 1, 2007 12:00 PM, By Robert Hanson

STUDIO DESIGNERS SHARE FIXES FOR COMMON ACOUSTIC PROBLEMS

In an ideal world, all audio would be produced in purpose-built studios that would allow for perfect isolation and accurate monitoring across the entire frequency spectrum. Unfortunately, the economics of the music industry have long made this scenario all but impossible for the studio masses. In fact, a great many audio professionals work remotely in rented spaces or private homes that were never designed with music production in mind. So what can be done to turn a less-than-ideal space into an accurate recording environment?

To answer this question, Mix tapped five studio designers who have worked on a wide variety of projects, ranging from complete remodels to semi-permanent improvements of existing spaces. Our experts — George Hallowell of Studio Pacifica, Chris Pelonis of Pelonis Sound and Acoustics, Richard Schrag of Russ Berger Design Group, Larry Swist of Lawrence P. Swist Designs and Carl Yanchar of Wave:Space — talk about many of the obvious and not-so-obvious acoustic problems that plague the average project studio and share which commonly available surface-treatment products can best mitigate these issues.

FASHION OVER FUNCTION

It probably doesn't come as a shock that some of biggest acoustic problems in the average project studio stem from a lack of physical isolation and poor low-frequency management. Many project studio owners also fail to solicit reputable advice and embark on ill-conceived improvement projects that often end up doing more harm than good.

“Noise intrusion is one of the biggest issues,” explains Swist. “Eventually, even the most sample-oriented productions need a vocal or some live recording, which usually ends up being the most dominant element in a production. Historically, the goal in studio design has been to achieve a recommended NC, or noise criteria value, between 15 to 20 in both the control room and the live room. If you own a sound-level meter, this is equivalent to an A-weighted sound pressure level measurement between 23 and 28 dBA. Most project studios don't have the luxury or budget to have sufficient isolation systems incorporated into their design, and consequently the operators have to contend with all the gear and drive noise, air-conditioner noise, birds, dogs, traffic and the unfortunate occasional event within the plumbing system.”

“One common error in the treatment of a cost-effective project studio is to cover the walls with 1-inch-thick foam and carpet the floor to reduce the reverb time and to hide or reduce any parallel wall reflections,” Hallowell adds. “Most small rooms, in fact, need only relatively small amounts of absorption to attain satisfactory reverb times. The absorption needs to be placed in the right positions and be of the correct type and thickness to keep the absorption relatively equal at all frequencies. Carpet and thin foam absorb high frequencies quite effectively, but it is very difficult to absorb low frequency with foam or Fiberglas unless it is quite thick or spaced far away from the wall — both difficult [to achieve] in a small room. There are corner foam products that are eight inches thick or so, but at very low frequencies, the air particle velocity nears zero as the wave approaches the wall, so products that work by slowing the air particle velocity, like foam or Fiberglas, will not be very effective. Low-frequency [energy] is more effectively absorbed, especially in small rooms, with membrane, panel or Helmholtz absorption, such as RPG's Modex unit.

“A third common problem is the lack of diffusion in project studios,” Hallowell continues. “The goal in the treatment of the room is not to make the room acoustically disappear. Some of the ‘sound’ of the room is both necessary and unavoidable. Remember that the goal of any well-treated room is to make the recording or mix in the room relatively flat and reproducible. That is to say, whatever you record in that room should sound the same no matter where it is played back. As it is necessary to absorb the right amount at the right frequencies, it is also necessary to provide the right amount of diffusion in the correct places.”

“Another problem I see is the pouring of money into projects at the direction of Websites, news groups and blogs,” Pelonis adds. “It takes an extremely rare and gifted individual who can wade through [all of that] and somehow glean the correct information to create a thriving, true and functional design. Please don't take this the wrong way; I am a huge fan of shared information on the Web. I occasionally browse through the discussions, and there is quite a bit of correct information out there and some very well-intentioned, qualified people providing it. The problem is that there is also a lot of BS. Acoustics is a very deep subject.”

THE NEAR-FIELD MYTH

With the availability of so many self-powered stereo and multichannel monitoring systems, as well as the deluge of accompanying marketing hype, many users have been lulled into a false sense of security when it comes to the accuracy of their studio. “The use of near-field monitors does reduce the sound of the room, but it can also create other potential concerns,” Hallowell says. “First of all, the use of near-field monitors does not remove the room sound. If it did, you would be mixing in an anechoic chamber. The room still has an effect.”

“Even with near-fields, if the monitors are loud enough for you to hear them, they're loud enough to interact with the room,” says Schrag. “For all the reasons that people find mixing on headphones to be unreliable, if the room doesn't play a part in what you hear, then it will be difficult to judge how imaging and panning and any spatial feel will be experienced by listeners who do play the music in real rooms.”

Speaker placement and orientation are also extremely critical issues that can create a whole host of other problems if not properly addressed. “Case in point: I was setting up a studio that we had just completed, and the owner had these MTM configuration monitors, with the tweeters in the middle and the mids on either side,” says Yanchar. “And they had oriented the speakers horizontally, and, of course, there were horrendous phase cancellations because of that. So even the orientation of the speaker is critical when you're that close.”

Thankfully, there are some very easy ways to check for proper speaker placement and make corrections for issues such as boundary effect, a common problem for speakers that are not soffit-mounted. Both Pelonis and Hallowell recommend using some widely available software applications that are designed to tackle these exact problems. “RPG has a very cool program called Room Optimizer,” explains Pelonis. “It will display a simulation of the effect of boundary interference with varying speaker/listener positions that are user-definable. I think it's worth the cost of admission just so people can understand the truth of what they're up against from a scientific standpoint. Subtle changes can have not-so-subtle results.”

“Near-field monitors should also be located far enough away from the listener so that the soundfield from both, or all of the speakers in the case of 5.1, has time to blend,” Hallowell adds. “Also, remember that all speakers should be the same distance from the listener and the correct angle in plain view. It is also a good idea to not mount the monitors on the table or console so that you do not get immediate reflections off the console or furniture.”

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