School Assembly Sound: Quick Guide for Non-Engineers

TL;DR

School assemblies happen in gymnasiums, cafeterias, and multi-purpose halls — spaces not designed for speech. If you are a teacher, administrator, or IT staff member responsible for making the assembly sound system work, this guide gives you a simple, non-technical measurement workflow to ensure the audience can hear and understand the speaker.

Before the Assembly (10 minutes)

Open SonaVyx at sonavyx.com/en/tools/spl-meter on your phone. No installation, no account needed — it just works in your browser.
Check the noise floor. Before turning on the PA, stand at the back of the room (the farthest seat from the speaker) and look at the SPL reading. With HVAC running and the room empty, it should be below 45 dBA. Above 50 dBA means the HVAC is too loud for comfortable speech — try reducing the fan speed if possible.
Turn on the PA and speak. Have someone stand at the podium and speak at a normal volume. At the back of the room, the SPL Meter should show 65-75 dBA. Below 60 dBA means it is too quiet — the audience will struggle to hear. Above 80 dBA means it is too loud and will be uncomfortable.
Walk the room. Walk from front to back and side to side while the speaker talks. The level should stay within about ±6 dB. If one side is significantly quieter, the speaker may need to be repositioned or a second speaker added.

During the Assembly

Monitor the level. Keep SonaVyx running on your phone. If the level at the back drops below 60 dBA (speaker is too quiet) or exceeds 85 dBA (music is too loud), adjust.
Watch for feedback. If you hear a ringing or howling sound, it is feedback. Turn the mic volume down immediately. SonaVyx's Problem Detector can identify feedback frequencies if you have time to investigate after the assembly.

Quick Troubleshooting

Problem	What You Hear	Quick Fix
Too quiet	Cannot hear at back	Increase volume, move speaker closer to audience
Too loud	Uncomfortable at front	Decrease volume, angle speaker upward
Echo / boomy	Words run together	Speak slower, use closer microphone technique
Feedback	Ringing or howling	Turn down mic, move mic away from speakers
Uneven coverage	Loud on one side, quiet on other	Reposition speaker to face center of audience

Room Improvement Tips (Low Cost)

Heavy curtains on walls reduce echo. Even temporary curtains improve speech clarity significantly.
Audience on risers or chairs (not standing) provides consistent ear height relative to speakers.
Microphone close to mouth (10-15 cm) gives the best clarity. Lapel mics and headset mics work better than distant podium mics in reverberant spaces.
Turn off what you can. Projector fans, open windows to traffic, and noisy air conditioning all compete with the PA system.

Tool Bridge

Open SonaVyx SPL Meter on your phone — no account needed, completely free. It shows you exactly how loud the sound is at any position in the room.