Page 13 - 2013 Spring

Fig. 6 Abbey Road Studio 1, London England (Abbey Road Studios, 2001)
Scoring stages are designed much like concert halls but without the requirements for an audience. The floors are flat and the walls and ceiling surfaces feature irregular shapes for diffusion. Reverberation times can be changed using move- able curtains or panels. For film, from 5 to 8 mics are used for the right-center-left and surround signals, and another 30 to 35 mics for individual instrument groups. The high ceilings sometimes make it difficult for the musicians to
hear each other so 12 to 18 foldback channels are provided from the mix board to individual players through head- phones. The orchestra can be seated on risers for visual cohesion and arranged to achieve a balanced sound.
Since sound stages are smaller than concert halls the orchestra cannot play quite as loudly as they would under performance conditions. When they do, the reverberation in the room, particularly the bass, can overwhelm the direct sound and yield a muddy recording. If the balance is correct and the control room is set up properly, the recording engi- neer can do a live mix including surrounds if necessary; however, the recorded tracks can be remixed at a later time, or used for sweetening.
The reverberation characteristics of a scoring stage are much the same as a concert hall. Abbey Road, in London, has a mid frequency reverberation time of about 2.2 sec- onds, rising slightly at the lower frequencies and remaining fairly constant at high frequencies. The lack of audience and seat absorption limits the falloff of the high frequencies to that due to curtains, musicians, and air absorption, so these rooms can be somewhat brighter than a performance hall. These stages have multiple hanging curtains, suspended on line sets from the ceiling, which can be lowered to reduce the reverberation time.
The recording of symphonic music can also be done in an empty concert hall. In these cases the room is often extensively modified to accommodate this use. For example, when Royce Hall at UCLA is used for recording, a wooden platform for the musicians is constructed over a portion of the seating area and the opera chairs in the orchestra section are covered with 3/4” (19 mm) plywood over visqueen sheets to decrease high-frequency absorption (Murphy, 2001).
Foley
Foley stages, where sound effects are generated by phys- ical manipulation of devices, are often indistinguishable from landfills, due to the general clutter. They were named for Jack Foley, an early sound effects pioneer. A typical Foley stage consists of a dead room with walls and ceiling covered in broadband absorption and a hard-surface floor having multiple pits each 3 to 4 feet square, in which there are dif- ferent walking surface materials. The Foley artists watch the film, projected on a screen against one wall, while making the sound effects with their hands and feet and an assort- ment of mechanical gadgets. For example, if the film requires the sound of running along a sidewalk, the artist runs in place on a concrete slab in time with the film actor’s steps, with a microphone suspended nearby. Gravel, wood, or sand may each have a separate pit. Water effects are creat- ed in a basin or large trough.
Since space is expensive, Foley pits sometimes are built into a traditional studio. This is less desirable than a dedi- cated space since recording studios are more reverberant than Foley stages and water is seldom available. Foley is messy and dirty and requires space around the pits for microphones and props. One approach is to build prop stor- age areas on the walls with absorptive panels mounted as
12 Acoustics Today, April 2013