Subwoofer

A subwoofer handles the low frequencies the main loudspeakers are not built to reproduce, typically everything below about eighty to a hundred hertz. At those wavelengths — a forty hertz tone is roughly twenty-eight feet long — sound stops behaving like a beam and starts behaving like a wave filling the room, which is why bass does not aim and why a subwoofer put in a corner gets louder for free.

The usual assumption is that thin bass means not enough subwoofers. More often it means the ones already there are fighting each other. Two subs spaced apart radiate into the same air, and wherever their outputs arrive out of step they cancel. The result is the aisle where the kick drum disappears while two rows over it is overwhelming.

The fix is arrangement rather than count. Subs grouped together in a block behave as one larger source. An end-fire or cardioid arrangement — several cabinets spaced and delayed deliberately — pushes energy forward and cancels it backwards, which keeps bass off the stage and out of the neighbours.

On a corporate show the same physics decides whether a presenter hears their own voice turning to mud. Outdoors, it decides how far the low end travels past the fence, which is usually what a noise complaint is about.

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

• Line array A column of loudspeakers hung in a curve so the sound reaches the back row without flattening the front — the standard answer for any room or field deeper than it is wide.
• 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.
• 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.