Show dictionary · Audio
Delay Tower
Also: delay stack · delays
A delay tower is a supplementary PA position partway back in a large audience area, electronically delayed so its sound arrives in step with the main PA. Delays restore level and intelligibility at distance without requiring a louder (and closer-punishing) main system.
In practice
The physics is the speaker delay calculation: sound from the mains takes roughly 3 ms per meter to travel, so a tower 100 meters out is delayed about 290 ms (plus a few milliseconds so the mains lead perceptually and the image stays downstage). Get it wrong and the field between systems smears into echo.
Festivals scale this into rings of delays, each zone timed to the one before it. The towers also carry video and sometimes spotlights, making them genuinely multi-department structures with wind loading and sightline politics attached.
How you’ll hear it
"Delays are set at 292 with an 8 ms haas; walk the seam and tell me if it smears."
Related resources
Part of the eventools.io Show Dictionary, a free glossary of live event production terminology.