Positive Listening

Live sound should be mixed from the audience’s perspective. While this statement may seem obvious, it is surprising how many venues locate the mixing position in a different room. However, the acoustical conditions that create this “room” may not be visible. This creates listening conditions that have a different balance of the voices and instruments, combined with the changes in tonal qualities, and result in frustration for the person mixing the event. Achieving confidence in the quality of the sound that the audience hears requires that the mixing position be located in the same acoustical conditions as the audience. This location must take into account the acoustical issues that create significant changes to the sound, including those invisible ceilings, which are often the source of mysterious changes to the sound during the show. A combination of acoustical awareness and suitable technology can often allow the mix position to be moved “into the audience” without losing too many seats to equipment and sightlines.

The most common problem with mixing locations, especially in venues with a permanent mix position, is the booth. This is a convenient location for the equipment that places it out of view and does not reduce the seat count. The booth may be room at the back of the venue, along the side wall or an overhang above the rear entrance. It may be a fully enclosed room with windows into the audience chamber or simply be an area partitioned from the audience. The worst case situation is the fully-enclosed room. Even if the windows can be opened into the venue, the sound that passes through them bears little relation to the balance of direct and reflected sound heard throughout most of the audience seating areas. The enclosed booth cannot be modified to give satisfactory results and will always depend on the person mixing to memorize the major differences between the sound qualities in the audience relative to those in the booth. The audience must suffer the imbalances that inevitably result. The locations that are not fully enclosed but are recessed into the wall share similar but less pronounced effects, including the buildup of low-frequencies at the boundary (wall) and notches in the frequency response caused by interference between direct sound and wall reflections. Balancing the acoustic and amplified sound, in addition to making suitable tonal adjustments, in a booth is like driving a truck while peering through binoculars.

Another common situation for the mixing gear is in a raised area at the back of the venue. Loudspeakers should focus the sound on the audience, avoiding the walls and ceiling. Locating the mixing position higher than the audience, and at the rear of the venue, will lead to a choice between two bad solutions: raise the coverage height of the loudspeakers to include the mix position; or leave the mix position outside of the loudspeaker coverage pattern. In the former case, the vertical coverage of the loudspeakers will be increased, adding unwanted reflections from the sound that is directed into the back wall instead of the audience. This may even require additional loudspeakers in the cluster to achieve this coverage, which adds to the potential acoustical interference between devices and to the cost of the loudspeaker system. However, it is even worse to have the latter case because, without being in the coverage pattern of the loudspeaker system, the person mixing is making judgments based on the off-axis sound of the loudspeakers (often with very little high frequency energy and spikes in the mid- and bass-response from loudspeaker lobing) in combination with a higher level of sound from the reverberant field. This location will often suffer from unusual balances between the sound arriving directly from the stage (acoustic sources, stage monitors and instrument loudspeakers) and the sound from the FOH system. Temperature gradients can create invisible ceilings in the venue (that develop during the show) that dramatically change the sound from the FOH loudspeaker and from the stage. Mixing from an area raised out of the audience is like driving the truck on the highway while only looking through wide-angle mirrors.

Technology can help by reducing the size of the processing equipment rack and mixing console. Then a place in the audience will be easier to find. Digital consoles that can provide more inputs in less space, combined with lower profile processing racks based on more compact signal processing, will reduce the area required by the mix position. That reduced size and a willingness to take a low profile to minimize the distraction and sightline issues, can make a strong argument for mixing the show from within the audience. This is like driving a truck over the hazardous highway of live sound while looking through a clean windshield.

United Entertainment Media Inc.
460 Park Avenue South, 9th Floor
New York, NY, 10016
Ph. 212-378-0400
FAX 212-378-2160
by e-mail

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