Entertainment noise limiters and the condition requiring one

A noise limiter controls the output of a sound system. It does not control a drummer, a saxophone, a singer without a microphone, a crowd, a propped open fire door or the taxi rank outside. If a planning condition requires a limiter and the complaints that follow are about any of those, the limiter has done its job and the venue still has a problem. Understanding that boundary before you accept the condition is the difference between a workable permission and a review in eighteen months.

Limiters come in three broad forms. A power cut device interrupts the supply to the amplifier when a threshold is exceeded, which is crude and unpopular with performers. An attenuating limiter reduces the signal progressively rather than cutting it. A multi band limiter does the same frequency band by frequency band, which is the only type that deals properly with bass. For most venues the multi band attenuating device is the right specification, and it is worth naming the type in the scheme submitted for approval rather than leaving it to the installer.

Setting the device against a measured level

The number that matters is not the one on the limiter. It is the level inside the nearest noise sensitive property, and the setting is derived backwards from it.

The commissioning sequence a competent acoustician follows:

1. Establish the criterion at the receptor. Entertainment music is usually assessed against the criteria in the Institute of Acoustics good practice guidance on noise from pubs and clubs, which is framed in octave band terms at low frequencies rather than as a single A-weighted figure, and compared against the background level measured in the same way. Confirm the criterion with the environmental health officer before commissioning, in writing.
2. Measure background. An unattended survey at the receptor position over representative periods, during the hours the venue will operate, including the quietest. The duration and position both affect validity, as set out in unattended noise monitoring duration, position and validity.
3. Play a controlled source through the installed system. Pink noise or a defined music track, at several output levels, with simultaneous measurement inside the venue at a fixed microphone position and inside or immediately outside the receptor.
4. Derive the sound insulation performance of the building between those two positions, band by band.
5. Calculate the internal level that corresponds to the criterion at the receptor, and set the limiter to hold the system at or below it.
6. Verify by playing the system at the limited level and re-measuring at the receptor.

Steps three to six are an evening's work with the venue closed, and they need the sound system that will actually be used. Setting a limiter against a hired rig and then installing a different one is a common and avoidable waste.

Who sets it and who keeps the key

The limiter should be set by a competent acoustician, not by the sound engineer and not by the installer working to a figure in an email.

Once set, the device needs to be physically secure: in a locked cabinet or enclosure, with a tamper evident seal across the adjustment, and the key held by a named manager rather than hanging in the DJ booth. The microphone, where the device uses one, needs to be fixed in the position used at commissioning and recorded with a photograph and a dimension, because moving the sensing microphone two metres changes the effective setting completely.

Build in a route for legitimate change. Venues alter their layout, replace speakers and add a stage, and every one of those changes invalidates the setting. A condition that requires re-commissioning by a competent person following any alteration to the sound system or the room, with the results submitted to the authority, is better for the operator than one that fixes a number for ever and turns every refurbishment into a breach.

Condition wording that can be enforced

Planning conditions have to be precise, enforceable, necessary, relevant and reasonable. Noise limiter conditions fail those tests regularly, in recognisable ways.

Workable wording does four things. It requires a scheme to be submitted and approved, specifying the device type, its position, the sensing microphone position and the internal level to which it is set. It states the criterion at the identified receptor from which that internal level is derived. It requires commissioning and certification by a competent person before the use starts. And it requires the device to be retained, maintained, kept sealed and re-commissioned after any change to the system or the room.

Ask for the draft condition before the decision is issued. Most authorities will share draft conditions on request, and a correction at that stage costs an email rather than a section 73 application.

The premises licence runs alongside, not instead

Two regimes apply, and they do not merge. A premises licence under the Licensing Act 2003 is granted against the licensing objectives, one of which is the prevention of public nuisance, and licensing conditions on noise are common. A planning condition is separate, enforced by the local planning authority, and survives changes to the licence.

Three practical consequences:

• Duplicate conditions in different terms are a trap. If the licence says one level and the planning condition says another, you have to meet the stricter, and you will be arguing with two departments. Ask for the wording to be aligned at the drafting stage.
• The licence is vulnerable to review. A responsible authority or any other person can seek a review following complaints, and the outcome can include new conditions or reduced hours. A well documented limiter commissioning record is the strongest material at a review hearing.
• Live music deregulation does not help with planning. The relaxations introduced for certain live music performances affect the licensing regime, not planning conditions, so a venue relying on them can still be in breach of a planning condition. Check both.

And separately from either, a statutory nuisance under the Environmental Protection Act 1990 can be pursued by the environmental health team regardless of what your conditions say. Compliance with a condition is a strong position, not an immunity.

Bass is where a single setting fails

The commonest technical failure in limiter conditions is a single broadband A-weighted setting on a venue playing amplified music with heavy low frequency content.

A-weighting discounts low frequencies deliberately, because it models human loudness perception for moderate levels. Building fabric also attenuates low frequencies poorly, and low frequency energy travels further and couples into structure more readily. So a system set to a comfortable A-weighted figure can still deliver a clearly audible thump in a flat above, and the complainant will be right.

What addresses it:

• Multi band limiting, with separate control of the 63 Hz and 125 Hz octave bands at a minimum.
• A criterion expressed in those bands rather than as a single figure, which is why the pubs and clubs guidance is framed the way it is.
• Attention to structure borne transmission, which no limiter controls. Floating floors, isolated speaker mounts, resilient hangers for ceilings and keeping subwoofers off a shared structure do more than any setting.
• A specification of the subwoofer position and mounting in the approved scheme, because moving a sub against a party wall undoes the whole exercise.

The Noise Impact Assessment supporting the application should cover all of this, together with any plant noise from kitchen extraction and air conditioning, which is assessed differently again and where the Ventilation and Extraction Statement does the odour side of the same installation. Councils expect a suitably qualified author for noise work, and professional review is strongly advised.

Records to keep after commissioning

Keep a commissioning file, and keep it where a duty manager can find it at 11pm on a Saturday:

• The commissioning report, with the background survey data, the measured insulation performance band by band, the derived internal level and the verification measurements.
• The settings certificate, naming the device, its serial number, the settings applied, the date and the person who applied them.
• Calibration certificates for the measurement equipment used.
• A photograph and dimensioned sketch of the sensing microphone position and the speaker positions as commissioned.
• The seal number, and a log of every occasion the cabinet has been opened, by whom and why.
• A record of any re-commissioning after a change, with the authority's acknowledgement.
• The approved scheme and the condition text itself, so staff know what they are complying with.

That file is what answers a complaint, a licensing review and a planning enforcement enquiry, and assembling it after the fact is never as convincing. The condition binds the premises rather than the operator, so it passes to whoever takes the lease next, and a clean file is worth something on a sale.

This is general guidance, not legal advice; check the position with your local planning authority, the licensing authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. To see which documents a venue is likely to need, enter your postcode on PlanScope.