Know your room before you play it.
Walk the venue, log sound levels from different spots, and get a recommended target for your mix. Stop guessing — start with data.
Microphone access needed
This tool uses your device microphone to measure sound levels. Nothing is recorded or sent anywhere — it all runs in your browser.
- No readings yet — walk the room and log levels.
Your room at a glance
Understanding SPL and your room
Everything you need to know to use this tool well — and to make better mix decisions at any gig.
What is SPL?
SPL stands for Sound Pressure Level — a measurement of how intense the air pressure waves are at a specific point in a room. The unit is decibels (dB). The critical word is specific point: the number changes dramatically depending on where you're standing, how far you are from the speakers, and what the room's surfaces are doing to the sound between the PA and your ears.
A phone microphone can't give you a calibrated, laboratory-accurate SPL reading — the hardware isn't precise enough for that. What it can do is give you consistent relative readings that let you compare one position to another in the same room. That comparison is exactly what this tool is designed to capture.
Why the stage is the worst place to judge your mix
When a band does soundcheck, they're usually standing on stage or right next to the PA. That position is acoustically nothing like sitting at a table 30 feet away near the bar. On stage you're close to the speakers, surrounded by monitor bleed from the wedges, and often in a loud reflective space near hard walls.
The audience hears a completely different version of the same sound. Bands routinely end up too loud because they keep turning up until it sounds right from where they're standing — which is the loudest spot in the room. By the time it feels good on stage, the front tables are being hammered and the bar staff are putting in earplugs.
What the spread between readings tells you
The difference between your quietest and loudest logged positions is often more useful than any single number. It tells you how acoustically consistent the room is.
A tight spread of 5 dB or less means the room is fairly even — you can set a level at one position and trust it holds across the whole space. A wide spread of 15 dB or more means you have real acoustic trouble: somewhere will be painfully loud before somewhere else feels adequate. That's the room telling you to fix the problem with positioning and EQ rather than keep turning up.
Wide-spread rooms are usually caused by low ceilings near the bar, hard reflective surfaces like concrete or glass, or a PA that's aimed poorly. No amount of overall volume adjustment fixes a room geometry problem.
dB reference levels for live music
These are the ranges you'll encounter in typical live venue situations. These are audience-position levels, not stage levels.
- 50–65 dBQuiet conversation, ambient noise in an empty room. Your baseline before the PA is on.
- 65–75 dBRestaurant background music, quiet acoustic sets. Comfortable for long periods.
- 75–85 dBModerate live music — folk, jazz, singer-songwriter. Present without fatiguing.
- 85–95 dBTypical bar band range. Energetic without being damaging for a short show.
- 95–105 dBLoud rock and dance territory. Ear protection recommended for staff working a full show.
- 105+ dBSustained exposure causes hearing damage. Venue staff have occupational health concerns at this level over a full shift.
How room acoustics change everything
The same PA at the same settings will produce very different SPL readings in different rooms — and even in different corners of the same room. Two factors drive this more than anything else.
Reflective rooms — bare concrete floors, low ceilings, large glass windows, hard brick walls — bounce sound rather than absorbing it. Sound builds up in the space and compounds on itself. These rooms feel louder than they measure, especially in corners and along walls where reflections reinforce each other. Turn down earlier than you think you need to.
Absorptive rooms — carpet, soft seating, heavy curtains, a full crowd — soak up sound energy. A packed house on Friday night will sound noticeably quieter than an empty room at soundcheck with the same PA settings. Experienced engineers always compensate upward when they know the room is going to fill up.
How to use this tool effectively
The goal is a baseline survey of the room before anything is playing, so you understand the acoustic character before the PA adds to it.
What is SPL, and why does it matter for live music?
SPL stands for Sound Pressure Level — a measurement of how loud the air pressure waves are at a specific point in a room, expressed in decibels (dB). The critical thing to understand is that SPL is a location measurement. The number changes dramatically depending on where you're standing.
The stage is the worst place to judge volume
When a band does soundcheck, they're usually standing on stage or near the PA — the worst possible position to judge how the room sounds to the audience. The stage is close to the speakers, full of monitor bleed, and acoustically nothing like sitting at a table 30 feet away. Bands routinely make rooms too loud because they're calibrating from the wrong spot.
Every room has a personality
A tight spread between your readings — say 5 dB from front to back — means the room is fairly even. You can set a level and trust it holds. A wide spread of 15 dB or more means you have acoustic trouble spots. Somewhere will be painfully loud before somewhere else feels adequate. That's the room telling you to pull back overall volume and fix it with EQ, not more level.
Walk it before the band arrives
Take your baseline readings while the room is still quiet. This captures the room's ambient noise floor and acoustic character before any PA is running. Once the band has done a rough soundcheck, walk the same spots again. The difference tells you exactly how much level the PA is actually adding at each position — not what it feels like from the stage, but what the audience is actually experiencing.
The numbers that matter
Quiet conversation sits around 50–60 dB. A busy restaurant with background music runs 65–70 dB. A live bar band playing well lands in the 85–95 dB range at the audience. Above 100 dB, hearing damage accumulates for people standing nearby. Above 105 dB, venue staff in a long show are in legitimate occupational health exposure territory. Knowing where you are in that range before soundcheck starts changes the conversation entirely.
Most sound engineers spend years developing an ear for this. Room SPL Scout gives someone without that background a data-anchored starting point on the first try — and gives experienced engineers a fast way to document what the room is doing before they trust their gut.
About this tool
Built by Corduroy Fields for gigging musicians. Free, no signup, no data sent anywhere — everything runs locally in your browser. Your microphone is never recorded.
Device microphones are not professionally calibrated SPL meters. Readings are relative, not absolute — most useful for comparing positions within the same room, not for regulatory compliance or hearing safety assessments.
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