Regulations · For guidance only
Sound limiters: what they are and when you'll be asked for one
It's the box that cuts the music when you go over the limit. Understanding how it decides when to cut will save you half a night fighting with it.
What it is
A limiter isn't a volume knob: it's a witness
Disclaimer. This article is for general guidance and information only. It is not legal advice. Specific obligations depend on the municipality, the type of activity and each individual application, so before finalising anything, check your local council's bylaw or ask directly at the department that processes the permit.
A sound limiter-recorder is a device placed between the sound source and the amplification that does two things at once. First, it limits: it prevents the sound level from exceeding its programmed value by lowering or cutting the signal. Second, and most often forgotten, it records: it keeps a time- and date-stamped log of levels and incidents that the authorities can request.
That second function is the reason it exists. Without a log, a limit is just a promise. With a log, there's a record of whether or not the activity complied with the conditions under which it was authorised.
How it works inside
The unit is installed in the rack, after the mixing desk and before the power amplifiers, so all audio has to pass through it. It has a measurement microphone placed at a fixed point in the room, usually specified in the acoustic project. The limiter continuously compares what that microphone picks up with the programmed value and acts accordingly.
It is usually sealed and programmed by an authorised company or technician, so neither the DJ nor the technician on the night can change the setting. The cut-outs aren't an equipment fault: they're the equipment doing what it's been programmed to do.
When it comes into play
Situations where it's usually required
With the usual caveat —it depends on the municipality and the type of activity— these are the cases where a limiter appears in practice:
- Venues with an activity licence for music: concert halls, pubs, nightclubs and banqueting halls. This is where it most commonly forms part of the licence conditions, along with the venue's acoustic test.
- Event spaces and estates that regularly work with amplified music. If the estate has one installed, your equipment simply connects to it.
- Casetas and activities at fairgrounds, according to what each council establishes in its regulations for the fair in question.
- Authorised one-off activities where the council imposes an emission limit as a condition of the authorisation.
And these are the cases where one normally doesn't appear: private events on private property without a music activity licence, indoor set-ups at low levels, or events with only spoken word and a PA. Even so, the absence of a limiter doesn't mean the absence of a limit: noise regulations still apply.
Living with it
How to set up without fighting the limiter
Most problems with limiters don't come from the limit itself; they come from setting up as if it didn't exist.
Find out before sizing the system
If there's a limiter, the sound system isn't sized by maximum power but by the real ceiling you'll be able to use. Bringing four times more equipment than the limit allows is pointless.
Ask where the measurement microphone is
The limiter measures at one specific point. If that point is right in front of a speaker, anything will trigger it. Placing the system with that in mind makes a big difference to the headroom available.
Spread across more points at a lower level
It's the same logic as with the regulations: more small speakers spread around generate a lower level at the measurement point than two big speakers flat out, and the audience hears better.
Keep the bass under control
Subwoofers are what most often trigger the limiter. Reducing their relative level and aiming them properly usually gives you several decibels of headroom across the rest of the spectrum.
Leave headroom on the desk
Running the desk at its limit and compressing everything makes the limiter cut in sooner and more abruptly. With headroom, the reduction is gradual and barely noticeable.
Tell the DJ
A DJ who knows there's a limiter sets their output level at the start and leaves it alone. One who doesn't know spends the night turning up, triggering cut-outs and turning up again.
Awkward questions
What people want to ask but don't
Can it be bypassed? No, and it's not worth trying. The unit is sealed and logs incidents, including tampering attempts and signal interruptions. A venue that tampers with its limiter is putting its licence at risk, and whoever does it on their behalf is putting their relationship with that venue at risk.
Why does it cut out when the sound isn't that loud? There are usually two reasons: the measurement microphone is picking up something different from what you hear —a nearby speaker, the crowd shouting, a bang— or the content has a lot of bass energy, which weighs heavily in the measurement even if you don't perceive it as volume.
Can I bring my own equipment if the venue has a limiter? Yes, but everything has to go through it. Plugging in a separate speaker that bypasses the installation is exactly what the system is designed to detect.
Who programs the value? Not the organiser or the sound company: it's set according to the conditions of the licence or authorisation, and programmed by whoever is authorised to do so under the applicable regulations.
Keep reading
Related links
Frequently asked questions
Questions about sound limiters
Do I need a limiter for a party on a private estate?
It depends on the estate and the municipality. If the estate has an activity licence for music, it probably already has one installed. If it's private property without that licence, there normally won't be one, but noise regulations still apply.
Do you rent out limiters?
The limiter is usually part of the fixed installation of the venue or space and programmed by whoever is responsible. We set up the system to work with whatever is there and size the equipment to the real headroom available.
Does a limiter ruin the sound?
If you work with headroom, you won't notice it. If you constantly try to go above the limit, yes: the system spends its time reducing the level and the result sounds compressed and lifeless.
What's the difference between an acoustic limiter and a limiter on the mixing desk?
The one on the desk or the processor protects the speakers from signal peaks. The acoustic limiter-recorder exists to comply with regulations: it measures the level in the room and keeps a record.
Does the venue have a limiter?
Tell us the limit you've been set and we'll set up the system so it sounds great below it.
