Line array

A line array is a vertical column of identical loudspeaker boxes, flown as one hang and angled against each other by small amounts. The angles are the whole point. Near the top of the array the boxes are almost parallel, throwing a long way with very little downward spread; towards the bottom they splay open to cover the seats directly underneath.

What this buys is evenness front to back. A single large loudspeaker obeys the inverse square law — roughly six decibels quieter every time the distance doubles — so setting it loud enough for row forty makes row three uncomfortable. A correctly curved array behaves differently over its working distance, losing closer to three decibels per doubling, which is the difference between a room that sounds the same everywhere and a room with a loud end and a quiet end.

The curve is not a preference. It is calculated from the seating plan before anything is hung, and it is why the array prediction is part of the drawing rather than something a crew decides on the day. Change the room depth, the stage height or the balcony overhang and the splay angles change with it.

Where an array stops working is distance, not volume. Past a certain depth the honest fix is not a bigger hang but a second system further back, timed to arrive late.

Event audio production — owned inventory, our own crew, and a site survey before anything is specified.

• Delay tower A loudspeaker position partway down a field or a long room, electronically delayed so its sound arrives just after the main system’s rather than before it.
• Subwoofer The cabinet that carries the bottom two octaves — and the one whose placement, not quantity, decides whether the room has even bass or a map of loud and dead spots.
• Front of house (FOH) The mix position out in the room where the engineer sits, and the audio the audience actually hears — not a department, and not a place a venue should treat as spare seating.