What usually goes wrong
- The back wall sends a late echo to the stage.
- Speech is clear near the front only.
- The sound system feeds back.
The main noise sources are the presenter and the sound system. Sound bounces off hard walls, floors and ceilings, so it lingers and builds up. Absorbing panels soak up those reflections.
Where the panels go
- The rear wall, which causes the slap-back echo.
- Upper side walls towards the back.
- Leave the front of the room reflective to help the voice carry.
Mistakes to avoid
- Deadening the front of the room.
- Leaving a concave rear wall bare.
Fire rating and codes
Assembly occupancy: finishes in exits and corridors must be Class A, and many jurisdictions require Class A in the room itself.
Blocking sound between rooms
Panels make a room sound better, but they don’t stop sound passing through a wall. For that you need a wall assembly rated around STC 55, to keep corridor and mechanical noise out of recordings and lectures. Read about STC ratings and soundproofing.
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Learning center
14 guides for lecture halls
Acoustic panels for lecture halls: the complete guideWhat makes lecture halls noisy, which panels fix it, and how to plan treatment from start to finish.How many acoustic panels does a lecture hall and auditorium need?A worked Sabine calculation for a typical lecture hall, with panel counts for small, typical and large rooms.Where to put acoustic panels in a lecture hall and auditoriumWhere panels do the most good in lecture halls, in priority order.Wall acoustics for lecture hallsHow walls behave acoustically in lecture halls and how to treat them with panels.Ceiling acoustics for lecture hallsClouds, baffles and ceiling tiles for lecture halls, and how much of the ceiling to cover.Choosing panel thickness for a lecture hall and auditorium1, 2 or 4 inches: which thickness suits lecture halls and why.Reverberation time targets for lecture hallsThe reverberation time to aim for in lecture halls, and why it matters.What acoustic treatment costs for a lecture hall and auditoriumBudget estimates for treating a typical lecture hall, and where the money goes.Fabrics, colors and shapes for lecture hallsFabric types, colors and shapes that work in lecture halls.Fire ratings and code requirements for panels in lecture hallsFire ratings, occupancy rules and mounting requirements for panels in lecture halls.Installing acoustic panels in a lecture hall and auditoriumTools, hardware and step-by-step installation for panels in lecture halls.Common acoustic mistakes in lecture hallsThe errors we see most often in lecture halls, and how to avoid them.Soundproofing and STC ratings for lecture hallsWhen lecture halls need soundproofing, which STC rating to aim for, and how to get there.Lecture hall and auditorium acoustics checklist and FAQA one-page checklist and answers to common questions about lecture hall acoustics.