Coverage first
The first question isn't what to use but where the audience is. A system exists to deliver even level and intelligibility across the seats, and that's a geometry problem: the shape of the room, the depth of the audience, the height available for flying, and the balconies, pillars and reflective surfaces in the way.
A line array answers that problem by combining several elements into a single controlled source whose vertical coverage can be shaped by how the elements are angled to one another. The array is then aimed so that its energy lands on the audience and as little as possible lands on walls and ceiling, because energy that hits a hard surface comes back as reverberation and takes intelligibility with it.
Low frequency
Subwoofers are a separate design problem, not an accessory. Low frequencies are long and largely omnidirectional, so an untreated subwoofer arrangement radiates as much energy behind the stage as in front of it (which fills the room with what the audience doesn't need and the neighbours will complain about).
How subwoofers are arranged (in a horizontal row, in a flown column, in cardioid or end-fire configurations) determines the pattern. The choice is driven by what the venue permits and by whether there's a noise limit at a boundary.
Amplification and processing
Modern systems are matched: a given loudspeaker is designed to be driven by a specific amplifier platform running the manufacturer’s presets, which supply the crossover, the equalisation, the delay alignment and, critically, the protection limiters.
This is one of the few places in the trade where substitution is genuinely not acceptable. Where a manufacturer has replaced an amplifier platform with a later one, the newer unit is the one a current system expects; the legacy unit may not carry the correct presets or the same processing capability, and running a cabinet on the wrong platform risks both the sound and the loudspeaker. When a system is specified, the amplifier is specified with it and by name.
| Decision | What drives it |
|---|---|
| Array size | Audience depth, throw distance, target level, and the flying height available |
| Subwoofer count and layout | Required low-frequency level, pattern control needed, and any boundary noise limit |
| Amplifier platform | Fixed by the loudspeaker (the current platform, not a superseded one |
| Fill systems | Front fill, out fill and delays for seats the main array can't reach cleanly |
| Rigging | Point positions, rated capacity, and the structural approval covering them |
| Power | Supply type, rating and position relative to where amplifiers will stand |
Control and networking
The console is where the show is operated, and its channel count, bus structure and processing have to suit the production rather than merely exceed it. Audio is distributed over a network, which brings its own requirements: switch configuration, redundancy, and clocking that's set deliberately rather than left to negotiate itself.
Rigging
Everything flown depends on the structure it hangs from. Point positions and their rated capacities are established from the venue’s own information before anything is planned, not assumed from a previous visit. Loads are calculated, motors and steels rated for them, and secondary safety provided.
This is the part of the work where the consequences of being wrong aren't commercial, and it's treated accordingly.
Redundancy
A production has one chance. Systems are specified with spare capability where a single failure would stop the show (a spare console path, spare amplifier channels, duplicate network runs) because the alternative is a room full of people watching nothing.