The hat squadThe sound-system consultant for a performing arts center wears many hats, acting as guide, facilitator and translator in a situation ripe for conflict.
Jan 20, 1997 12:00 PM, By Paul GarrityGarrity is a theater consultant and head of sound-system design for Auerbach + Assoc
Oh, I've designed nuclear plants before. They're much easier than theaters!
This quote, from an electrical engineer we know, is no joke.
The successful design of a performing arts center is an extremely complex task, with many sources of potential conflict among the needs and desires of the architect, the theater planners, the acoustician, the lighting and sound-systems designers, the mechanical, electrical and structural engineers, code authorities, and the end-user and facility management. Many of the most crucial decisions must be made early in this process, decisions that even the most talented and knowledgeable end-user will not have experience making.
These are the decisions that must be made early. By the time a contractor, even a design-build contractor, is brought onboard, it will be too late to make substantial changes, by a factor of months, perhaps years. When taking on this sort of project, the design of a performance venue, you must address some substantially complex issues.
While we are focusing on sound and communications systems design issues, keep in mind that these are only part of the whole project - the building cannot live on sound systems alone. When the decision is made to build or renovate a theater, showroom, concert hall, theme park attraction or house of worship, you have your work cut out for you.
It is necessary to integrate the needs of the end-user and, by extension, the needs of all the various consultants and engineers into a building that will meet all the applicable codes and standards and will suit the intended program - and come in within the budget.
If the project is proceeding normally, the budget is probably too low, the time available is probably too little, and the expectations are probably too high. The end-user may have very specific and well-considered ideas for the type of system needed: the loudspeaker clusters, mixing console, signal processing rack and other gear. Perhaps the person has been working in the hall for a number of years and has determined exactly what is needed for sound and sound-effects mixing and playback or for a digital production workstation. But whether the end-user knows it or not, she probably needs help, and the sooner she gets it, the better.
Cooperation requiredHowever highly qualified and experienced the end-user may be as a sound engineer or designer, if he has never gone through the process of building or renovating a building, he may be in for a bumpy ride. The right consultant is one who works with the end-user to develop systems that serve both current and future needs.
*The consultant must have experience working with the architects, electrical engineers, installation contractors, general contractors, cost-control specialists, structural and mechanical engineers, and with the boards of directors or the other governing bodies responsible for the projects.
*The consultant has to be able to wade through all the code issues, the politics, the budgeting exercises, the design development and contract documents phases, the tendering and bidding phases, shop drawings review - in short, all the issues about sound, video and communication systems design that the end-user will not have experience with.
*The consultant must also be able to lend credence to the stated needs of the end-user as a qualified second opinion to help convince the money people that the equipment and systems requested are actually necessary. Even a design-build contractor reaps benefits from having an experienced consultant on the design team onboard early enough to correct building architectural and infrastructure problems before it's too late to make substantial changes.
InfrastructureAs the pace of new technology increases, it seems best to discard any notions of a permanent house sound system. From the moment a system of any complexity is installed, an experienced end-user will be considering changes, upgrades and adjustments to keep pace and to tailor the system to the changing needs of the venue. What will not be changing as rapidly is the back-of-house systems: the intercom and paging systems, wiring, cable, power infrastructure, data distribution, video distribution systems, listening systems for the hearing impaired and other support systems. If the back-of-house systems are not done correctly now, they may never be right, and it's extremely difficult to find the money to upgrade these backbone systems later, when the focus will be on upgrades, such as the latest processor or mixing desk, and on parts and cables and other "consumable" items. The end-user won't be interested in upgrading the paging system or the video distribution system for quite some time.
Most electrical engineers and contractors will not have had experience in providing a properly detailed power and conduit infrastructure for a complex performance sound and communication system, so it is up to the consultant to fill in the gaps, providing the necessary information and expertise.
Ensuring that the proper infrastructure is in place is of primary concern. If the conduit and power backbone isn't designed properly in the beginning, it will be extremely difficult to fix it later. First emphasize power, then conduit and wire. Starting from the source, determine the total electrical load anticipated for the new systems, leaving room for expansion. Working with the electrical engineer, determine the quality of the power source to decide upon the type of isolation transformer and power conditioner required. This equipment can be quite expensive and is often overlooked during the budgeting process. Deciding how the system's technical ground, the isolated source, will be connected to the building safety ground and meet code is of utmost importance.
Power distribution and grounding is the next issue to cover. For example, do you want to control the distribution of phases in the system so the primary console is on the same phase as other key components in the system? If you do that, the power amplifiers will need to be evenly distributed across all three phases to balance the load.
Once the main electrical system is on paper, bring your attention next to the intercom, paging and video distribution infrastructure. The facility may need video projection systems or other A-V systems, or perhaps the project is a university or church requiring classroom as well as theatrical production systems. Additional infrastructure for broadcast or electronic media must also be incorporated as necessary.
Step by step, inch by inchOne of our firm's current projects is the design of a number of university performing arts centers. Each has different performance spaces, such as a 2,000-seat concert hall, a smaller recital hall, a proscenium drama theater, an adaptable studio theater, a dance theater and rehearsal rooms for music, dance and theater. Within the facilities are links to campus and external electronic media and to recording and broadcast production facilities. The project also includes a number of dressing rooms, shops, production support spaces, classrooms, an outdoor courtyard and space for amphitheaters. Most of these are in one large facility, with integrated functions and shared system requirements.
The projects are receiving government and university funding and are being run by the individual design departments under the auspices of the university management, and all must comply with myriad government codes and university standards and practices. Budgets, as always, are tight and are continually being whittled down, bit by bit, piece by piece, chunk by chunk.
At the beginning of this project, we worked with the architect to identify locations for the local control rooms or equipment rack rooms for each space. We also indicated a suitable location for a central communications room to house the equipment relating to MATV-type video distribution, building-wide show monitoring, paging and production intercom central control, programming and links. This communications room serves as the central node for audio and video tie lines from each space feeding to a central recording room.
Then we located the in-house mixing positions in each performance space, which in smaller rooms simply involved providing a panel in the floor or wall with connections and power or merely a cable pass to a nearby control room and designating a section of removable seats. Larger spaces may demand a permanent house mixing position, carefully located to have a minimum effect on seat count and audience sightlines.
Concert hall venues, where sound-system needs vary from none to extensive on a night-by-night basis, can benefit from more elaborate solutions, such as a cockpit lift system. In this scheme, the entire mixing position is built onto a wagon placed on a permanent lift at the mixing position. The lift can lower this wagon into a basement storage position just below the audience seating, at which point the wagon is rolled off the lift deck onto a storage platform - without requiring connections or cables to be unplugged. The empty lift can then be raised back up to provide space for a touring console, or a second wagon preloaded with additional audience seats can be raised into position, making it impossible to tell that a mixing position was ever there. The entire changeover can be accomplished in less than five minutes by one stagehand.
It's electrifyingRegarding power, extra money spent in the beginning can save a bundle over the life of the building. We provided criteria to the electrical and mechanical engineers for overall power and HVAC loads, taking into account the range of power and heat loads generated by power amplifiers, both idling and during operation at high output. We explained the need for touring system disconnects on stage and at a broadcast truck position, if any. The 200 A three-phase isolated-ground disconnect is specifically designed to take touring cable connectors or, if necessary, bare leads. The criteria for these switches are based on the size of the room and the intended program.
We gave accommodation plans to the engineers and architect, detailing all the sound and communications panels and devices, showing all wiring requirements and cable types, panel sizes and mounting information. We worked with the electrical engineer on conduit layout and raceway infrastructure, provided wire counts, ensuring that the conduit sizes were sufficient, and identified spare conduit runs for possible expansion.
We identified riser locations and provided criteria for conduit spacing so sensitive microphone circuits would not be run directly adjacent to dimmed lighting circuits. We decided which type of conduit, whether metal, PVC or a barriered raceway, was appropriate for each location. We coordinated the location of panels with those of the other systems so that crowded areas, such as downstage left and right, control rooms or the upstage wall would be kept clear of panels. We designed the systems for the paging loudspeakers, the intercom and coaxial direct and MATV video points, broadcast quality triax points and the location of all the other devices and panels.
Designing the systemsOnce the necessary infrastructure is in place, system design begins. We're probably working a year, maybe two or three years, in advance of the building's opening day. Therefore, we must do some crystal-ball gazing to ensure we're not selecting equipment or systems that will become obsolete quickly, yet at the same time we must ensure that we're not gambling on untested systems or equipment that never gets beyond vaporware. We pick the headend for the paging and production intercom systems, integrating the two where possible, and locate the portable production table positions and stage manager's desks.
We design the video systems, both the show-relay cameras and distribution and, when necessary, any in-house production camera equipment, including infrared cameras for viewing scene changes during blackout conditions.
We locate the infrared emitters for the assisted-listening system for the hearing impaired and decide whether a multichannel system is required to accommodate blind-description or simultaneous interpretation.
Loudspeaker arraysWe provide plans and elevations of all the major loudspeaker arrays, working with the architect on the most difficult aspect of coordination: whether the loudspeakers would hang in view of the audience or be concealed. We are constantly struggling with this issue, dealing with both the added costs involved in trying to hide the loudspeakers and the inherent compromises that can occur in the process. Common compromises include placing the arrays on permanent winches so they can be raised out of sight when not in use or lowered to the floor for service or removal. If such an approach is used, it may be necessary to provide an additional speech-only system to permit announcements to be made during what is otherwise a "pure" symphony event. Concert halls with moving or stationary acoustic canopies or orchestra shell ceilings can cause additional difficulties when these ceilings are in the way of the optimum loudspeaker array position. In addition, the lighting designer may have a fit if this optimum position turns out to be in the way of that first or second front-of-house lighting position.
Of course, the acoustics of the room must be carefully considered. Concert halls can prove the most difficult because the acoustics can be quite live, even when "variable acoustics" devices are used, such as drapes, banners, reverberation chambers or even electronic enhancement systems.
Many concert halls use a wraparound approach to the audience seating as well, so the audience is behind and at the sides of the stage as well as in the main floor and multiple balconies. The balcony fronts, however, can cause strange and interesting reflections that may be wonderful for symphony needs, but terrible for a sound system. Also, the shape of the rear and side walls can produce some rather difficult anomalies.
The end-userWhile all of this is happening, we are in constant touch with the client and end-user, reviewing equipment choices and program needs, ever mindful of budget restrictions. At the university, we dealt with nearly every type of end-user all at once. The needs of the drama department were considered: designing an appropriate theatrical sound effects creation, production and playback system for the studio theater. Classroom and teaching systems were needed in their respective areas. The facilities included a concert hall and a large auditorium, each of which would be used for a mix of in-house and touring production. The client, of course, correctly demanded that the systems be extensive, yet simple to operate.
The university also has a strong music department, and another consultant is providing extensive electronic-media provisions and infrastructure. The end-user had specific desires for equipment but also needed the best approach to sound-effects playback in the theater, whether regarding the pros and cons of recordable CD or mini-disc, selection of mixing consoles and microphones, or computer platforms for production systems.
Having an interested and talented end-user onboard throughout the design process is essential. Designing in a vacuum is not much fun, and having a house sound engineer appear after all the design work is complete can be just a little disconcerting. After all, it's not like we all agree on the right wayto do things.
But if things are done right, early on in the project, the sound-system consultant can meet the needs of the end user and satisfy the requirements of all of the many principals involved in the design of the center.
Questions, questions, questionsThe design of sound, video and performance communication systems for a performing arts facility is a difficult challenge, one requiring experience, diplomacy and a good deal of patience. But half the battle is won if you know the critical issues and address them early. As the consultant, you must help define the many issues relating to the building's infrastructure and sound reinforcement. You must work with the end-users and find out the answers to each of the following questions:
*Will power sequencing be required for the power amplifiers? What type of system will be best?*How much power will be needed for the touring system disconnect or company switch or for outside broadcast or recording vans?*What heat load will be presented by the amplifier rack room and control rooms to the HVAC system? Does the system use self-powered loudspeakers, each with an integral power amplifier, thus completely changing the necessary wiring, power and HVAC requirements?*How far should microphone conduits be placed from dimmed lighting or high-voltage conduits?*For that matter, what country are we working in, and what are the local power standards and code requirements?*How many microphone circuits will be needed at what locations?*Will this be enough to serve future needs?*Will spare conduits be provided to allow for expansion?*Is it appropriate to consider the use of a fiber-optic network?*What kind of connectors should be specified? XLR-type? Multipin? BNC?*How will these connectors be isolated from the conduit ground to avoid ground loops and shorts?*How will the panels be labeled, and how will the circuits be numbered?*Should provisions for a data wiring infrastructure or MIDI distribution be included? What will the communication needs be?
Typical systems in a performance venue include stage monitoring and paging to back-of-house areas, as well as to front-of-house lobbies and public areas.*Will the client want audience recall?
A listening system for the hearing impaired is now required, in the United States as a part of the Americans with Disabilities Act mandate. This system requires its own decision-making:*What sort of system suits the client best? Infrared or FM?*Will a multichannel system be desired for simultaneous interpretation or for description for the blind?*How extensive will your paging system be? These systems can get quite complicated, especially if you are designing a venue with multiple performance spaces. The system will need to address a multitude of conditions, yet be so easy to operate that a touring stage manager will be able to operate it will little or no instruction.*Is the venue primarily a road house, or is the program mainly in-house production?*Is it a concert or multipurpose hall?*If it is a road house, how will touring systems be accommodated and installed? Some tours use none of the house system or equipment; some will want to tie into the underbalcony delay systems or your main loudspeaker clusters as primary system or to supplement the touring systems. Some will use their own console; some will use your house console. Some tours will use your house wiring and microphone splitter system, if you have any; some will be looking for routes to get their touring multicables or "snakes" from the mix position backstage. Will you permit these cables to be run down the center aisle, or will you want to provide a system of cable passes or troughs for the touring companies to use? If cable passes are provided, they must be well -designed. If they prove too difficult to use, they will not be.*Where will the mixing position be located? How many seats, if any, will be lost? Will touring companies be willing to mix from the position you have designated?*Does your venue support television or radio broadcast or recording?*Are the facilities for this in-house, or will they be performed from an outside broadcast truck? Where will the truck be parked? Will the truck impede normal access to your loading dock, or will the truck be able to get-in when it is in use? How much power will be required by the truck, and how many, if any, microphone, line-level, video, intercom and other circuits will be provided for use by the recording or broadcast personnel?How will the loudspeaker clusters be installed? Will they be dead hung out in the open? Will they be on a winch or a chain hoist? How will you access them for servicing? Will the architect insist that the loudspeakers be hiddenbehind decorative panels? How will these panels be constructed, and what will be their effect, if any, on sound-system performance?*Will it be possible to easily add loudspeakers or alter the placement of the existing loudspeakers?*Where will the amplifiers be located?*Will the system have powered loudspeakers?*Are the amplifiers in a remote rack?*How will these amplifiers be monitored and controlled?*How will the audio and control signals be sent to the amplifiers: in a traditional analog fashion, by an Ethernet connection or by fiber-optic link?*When is computer control desirable?
For all these questions, the consultant acts as an experienced guide, facilitator and translator, keeping an eye on all the parties involved, the architect, engineers and the budget processes.