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Can your PA actually reach your crowd?

Three questions. You'll get an estimate of how far your sound stays clear, how many speaker positions it would take to cover everyone, and how much quieter the back row is than the front.

Include the overflow room, the queue, and the patio — everyone who should hear you.
Open ground loses sound fastest; hard indoor surfaces blur it fastest.
Be honest — this changes the answer more than anything else.
How this is calculated

This is a planning estimate, not a system design. It assumes a good powered speaker producing a realistic sustained level of about 103 dB at 1 metre, already derated for wind, air absorption, off-axis listeners, and a crowd that absorbs high frequencies.

Sound is modelled as dropping 6 dB per doubling of distance. Speech is treated as intelligible while it stays about 15 dB above the ambient noise floor, with an extra penalty added for reverberant rooms where reflections blur consonants without reducing volume. The ambient figure rises with crowd size, because a crowd is its own noise source.

Each speaker position is treated as covering a 90-degree wedge, with about 1 square metre of floor per standing person. Real venues have obstructions, odd shapes, wind, and rules — always confirm with whoever is providing your sound.

What to do with the answer

One position? A standard PA will do the job. Get the speakers up on stands at roughly ear height and you're done.

Two or three? You're into delayed speakers, which means timing them so their sound arrives with the main system. Untimed rear speakers sound like an echo and make clarity worse. Budget for someone who has done it before.

Four or more? You have crowd overflow. Speakers can still solve it, but you're now buying a production rather than renting a PA — and if the venue has a noise limit, this is the point where volume stops being available at any price.

Spread across several rooms? No single speaker system covers this. Your options are separate systems per space, or delivering the audio to people instead of to the room.

The other way to read this result Every number above is a function of distance. Stream the same audio to each attendee's own phone and distance stops being a variable at all — every listener is one metre from their own speaker, whether they're at the front barrier or in the overflow room.

Reach everyone the speakers couldn't

Instant Audio streams your live event to the phone already in every attendee's pocket. No headphone rentals, no delay towers, no per-person hardware.

Start free with BYOPA Read about crowd overflow