So, imagine you are in a band, or in sales at the local Circuit City, or maybe just know how to solder. And you have some friends at the local community theater, or in the drama department of your school. And they say; "Hey...we're about to do Sound of Music for our Fall show...do you think you could come down and help with the sound?"
Especially at a smaller or less experienced theater, they may not know what it is they need, and what your job will eventually entail. Let me lay it out for you up front; your responsibility becomes the total sound environment of that building.
Everything. If you want to make that show the best it can be, your job does not stop at putting some microphones on the actors. It begins with looking at the acoustical space (say, finding out if you can drape a particularly reflective wall, or if the noisy HVAC can be turned off during the performance), extends down into the pit (you might even end up helping to program the synthesizers!) and can also encompass backstage monitoring and paging systems so the actors in the dressing rooms can figure out where they are in time to make their entrances.
But let's stop and quantify this. Basically, the tasks you may be faced with divide into the following categories:
1) Vocal Reinforcement (amplifying the actors so that the audience can hear and understand them properly).
2-a) Orchestra Reinforcement (amplifying, shaping, clarifying the orchestra mix for the benefit of the audience)...
2-b) Playback (the systems to send pre-recorded music to audience and to actors). ((Or not 2b; that is the question!)
3) Foldback (sending orchestral material to the actors, so they can find their place and pitch; sending vocal material into the pit so the conductor can hear the singers in return; and sending specific instruments around the pit so different members of the orchestra can hear what they need to hear to play together).
4) Effects Play-back and Processing (sound effects, and special processing for environmental affect or to shape specific performances).
4-b) Practical Effects (real doorbells, phones and the like, wired to be operated as effects but part of the total sound picture).
5) Monitor and Hearing Enhancement (not always tied together, the systems that allow cast in the Green Room to hear where they are in the performance, and late-comers to watch and listen from the lobby before there is a convenient place to seat them; AND the system made available to the hearing-impaired patron, otherwise called the Assistive Listening Devices).
6) Communications (in large venues a proper intercom and paging system already exists. But you still might end up having to repair it, expand it, patch into it, or otherwise work with it).
7) General Noise Abatement (being the person to speak up about noisy fans and lighting effects, putting rugs backstage, acoustic treatment of the building and the pit, etc.).
Let me break down this seemingly indigestible list with a look at what I've got in a show that opened this weekend:
There are a bit over twenty wireless microphones -- body mics -- on the cast. These are mixed by the house technician from a booth in the back of the auditorium, and sent into the house speakers.
In addition, there are a half-dozen mics scattered around the orchestra pit, basically mic'ing by section, which are also sent to the house speakers during certain moments when the orchestra (who is in a covered pit) would otherwise not be clear (or powerful) enough.
The last major thing the audience hears (besides -- no small matter! -- the direct acoustic energy from the on-stage performers and the pit orchestra) is sound effects, played back from a laptop operated from the booth, and sent to different sets of speakers dependent on the desired placement in the acoustical space (aka, where the sound should seem to be coming from).
In addition to this, selected instruments (mostly piano and bass) are picked up by microphone and DI and sent to a combination of floor monitors and hanging monitors surrounding the acting area, reinforcing the parts of the music the cast most needs to hear.
Going in reverse, the wireless microphones are submixed down to a small vocal monitor at the feet of the conductor, in the pit, so she can hear the singers.
So that's essentially three semi-independent systems, with their own set of mics and speakers, running in different directions. In a different house I work at, we have two different sets of speakers aimed at the audience; the vocal reinforcement is sent to one and the orchestration is sent to another; that separation in space makes it easier for the audience-listeners to hear them as separate elements.
Both houses have existing monitor and communication systems, at least, so I didn't have to deal with those. At another house where I worked as Master Electrician, I can describe those linked but essentially independent systems in detail:
A Clear-Com base station, serving two channels of headset-type intercoms with stations and jacks spread around the theater (backstage, booth, grid, etc.) The Stage Manager's headset was tapped to allow him or her to use the headset in paging mode, speaking over the monitor feed normally sent to a series of 70-volt speakers spaced around the dressing rooms and Green Room.
This monitor system was, in turn, driven by a single microphone hung over the stage. The Sennheiser hearing enhancement system piggy-backed on this same microphone, driving three infrared emitters that could be picked up on headset units given out by the box office to hard-of-hearing patrons.
(There was also in this house a third communications system, consisting of a 48v Bogen intercom system. It was only used for communications between House Manager and Stage Manager.)
The show and systems you end up on may be as simple as a CD player, a pair of speakers, and two floor mics; but it still helps to think in terms of Reinforcement/Processing, Foldback, Effects, Communications, and Monitor.
For each system, and at each stage of the game, you should be thinking of the total sonic environment. What does the audience ultimately need to hear? What is important to tell the story, communicate the emotion, be honest to the harmony and structure of the music?
You start and end with listening. Before you throw a piece of technology at a problem, see if it is a problem, and if that is the best place to fix it. Maybe, rather than mic the bass, piano, drums, oboe, and strings, just to get them up level with that one loud trumpet player, there is a way you can take the trumpet down instead. Talk to the conductor and investigate options before you start throwing microphones around.
Same for the cast. Same for everything. Is there a door slam in the show? If the shop can rig up a proper wooden door in a frame, the actor can slam the door; it will nine times out of ten sound more realistic, and ten times out of ten have better timing.
Which is not to say all technology should be avoided. But what you should look at is the basic problem you are trying to solve, and solve it in the most elegant manner possible. Maybe a couple of floor mics will handle the chorus vocals fine, and save you from having to cover an entire cast in wireless mics. Conversely, maybe a pre-recorded telephone ring is simpler than running wire down to an on-stage phone and making or purchasing a bell ringer.
Always keep in the back of your mind that you will be stuck with this for five weeks of constant performances, operated by tired, stressed people who may not be that technical, and if an effect flubs or a mic goes out the whole intricate ballet of acting and dance and lighting that is a performance may fall apart. Whatever you do, make it as much as possible bulletproof and easy to diagnose and repair.
Be prepared to defend the necessity of your choices. A truism quoted by sound designer and composer James LeBrecht; "Everyone in theater knows two jobs; their own and sound." People will be constantly shocked by the complexity and price of what you want, will be unbelieving of how sensitive some of the details (like specific mic placement, like routing sound cables away from electrical wiring) can be, and even of the basic physical principles involved.
You'll find yourself in more than a few "Scotty" moments ("I canna change the laws of physics, Captain!") Because, as James LeBrecht noted, everyone thinks they know how sound works. You practically have to beat them over the head with a hard-bound, 500-page "Fundamental Principles of Musical Acoustics" before they get that their naive intuition about some specific sonic situation may be WRONG. Just because, for instance, they've never heard of intermods, or the White Spaces edict, doesn't mean the RF spectrum is going to play along and give you trouble-free performance on those finicky wireless microphones.
But I digress...this leads to a rant instead.
And since this essay was too poorly organized to begin with, and I'm getting hungry now, I'm going to stop here. Perhaps when I return to the subject I can describe just what a vocal reinforcement system looks like, including some of the specific choices and techniques for placing mics, protecting transmitters, and the like.