The chair of the charity stands up between the main course and dessert and thanks everybody for coming. On the tables furthest from the stage, the conversation carries on. They cannot make out enough of what is being said to bother trying, and turning the system up will not fix it. Gala dinner AV hire, meaning the audio visual (AV) equipment and crew brought in for an evening like that, is mostly a fight against a room built for eating.
In short
- A dining room is hard and reflective and full of people talking, so speech has to sit well above the noise underneath it before anyone listens.
- Raising the system level does not close that gap, because a louder room makes guests talk louder too.
- Where the loudspeakers go and which microphones are used matter far more than how much power the system has.
What gala dinner AV hire has to solve
A banqueting suite is a difficult room to hear in before a single guest arrives. The surfaces that make it look right, the plaster and the mirrors, reflect sound instead of absorbing it, so every word arrives twice: once from the loudspeaker and again off the walls. The second arrival smears the first.
Then the room fills. Round tables put half of every table with their backs to the stage, and several hundred people talk through the service. That is what separates a gala dinner from a conference where everyone faces the front in silence. The job is to put speech on top of all of it clearly enough to follow from the back, which is not the same as making the room loud.
The room gets louder faster than the speech does
There is a reason the volume control stops working. People raise their voices when the room around them gets noisier, without deciding to, and not by enough to keep up.
Researchers measured that using recorded restaurant noise, published in Scientific Reports in 2022. Above roughly 58 decibels on the A-weighted scale, which approximates how human hearing responds, talkers lifted their voices by only about half a decibel for every decibel the room gained. The gap between a voice and the noise underneath it narrows as the evening goes on. Push the speeches up and the tables who were not listening simply talk louder.
How far ahead of the room speech has to be
Systems for speech are designed around a signal to noise ratio: how far above the background the speech sits. British Standard 6259 recommends a minimum of 10 decibels, and that figure gets repeated often enough to be treated as settled.
It is not. Peter Mapp, writing for the Institute of Sound, Communications and Visual Engineers, points out that 10 decibels guarantees nothing on its own, because what a listener understands depends on the reverberation in a room as well as the noise in it. Outdoors, 3 to 6 decibels can be enough. In a reverberant indoor space, 15 to 20 may be needed. A banqueting suite full of diners is firmly the second case, which is why a public address (PA) system that sounded fine in the empty room can fail at nine.
Where the loudspeakers go when the floor plan is full
The instinct is a pair of loudspeakers either side of the stage, turned up until the back of the room is covered. That hands the front tables a level they resent and the back tables one they still cannot use.
The alternative is more boxes, each doing less: smaller loudspeakers spread through the room so nobody is far from one, timed so the nearer box does not arrive ahead of the stage. Each of those positions has to live somewhere that is not a table or a sightline, which is the same negotiation that deck height and sightlines already put you in.
We met that at the Hilton Liverpool Star Ball, where the brief for the audio was to cover the whole of the Grace Suite without interrupting anyone’s view of the stage or taking up floor space the dinner needed. The loudspeakers went behind the projection screens and into the window bays. Positions like those get found on a site visit.
Microphones at a top table
Most speech problems at a dinner are settled by the microphone rather than the loudspeakers. Shure’s guidance on controlling feedback comes down to getting the microphone closer to the talker, keeping microphones and loudspeakers as far apart as the room allows, and switching off the ones nobody is using.
All of it is harder at a dinner. A microphone left standing on a top table sits an arm’s length from whoever stands up, so the system has to be pushed to compensate, which brings the room and the loudspeakers straight back into it. A handheld or headset microphone a few centimetres from the mouth needs far less gain for the same result. Every open microphone also adds room noise, so six radio microphones laid along a panel table is a worse start than two that get passed along it.
The guests who will not hear it whatever the system does
At a dinner of a few hundred people there will be guests with hearing loss, and a louder system is the one thing that does not help them. A hearing loop sends sound straight to a hearing aid or cochlear implant, which as the RNID puts it cuts out background noise and makes speech and music clear.
Plenty of hotels have a loop fitted in the main suite. Fewer can say whether it still works, or whether it is fed from the desk your crew is mixing on instead of a lectern microphone nobody is standing at. Those are questions for the site visit, and where the answer is no, receivers and headsets can be brought instead. The Equality Act 2010 protects guests who are deaf or have hearing loss from being offered a lower standard of service, which is a firmer footing than good manners.
Frequently asked questions
Why can guests at the back never hear the speeches?
Usually because the speech is not sitting far enough above the noise in the room, and because reflections off hard surfaces arrive just after the direct sound and blur it. Adding level makes both of those worse at the front while doing very little at the back. Coverage from loudspeakers placed through the room, not power from two of them at the stage, is what actually fixes it.
Can we use the venue’s ceiling speakers for the speeches?
Rarely, if the speeches matter. Ceiling systems in hotels are specified for background music and announcements in a quiet room, not for intelligible speech over several hundred people at dinner. They are also usually fed from a wall plate instead of a mixing position, so nobody can adjust anything as the evening changes. Ask what the system was designed to do before assuming it will carry a speech.
When in the running order should the speeches sit?
Between courses rather than during one, and early in the evening. Service noise and conversation both rise as the evening goes on, so a speech placed after dessert competes with the loudest version of the room. Pausing service for the speeches makes more difference than any piece of equipment, and it has to be settled with the venue in advance. The running order decides all of this, exactly as it does at an awards ceremony.
Sources
- Institute of Sound, Communications and Visual Engineers · Peter Mapp on signal to noise ratio
- Scientific Reports · Bottalico, Piper and Legner on the Lombard effect in restaurant noise
- Shure · How to control feedback in a sound system
- RNID · Providing a hearing loop in your venue
If you have a dinner in the diary and the speeches matter as much as the room looks, we are happy to walk the space with you before anything is specified. We supply audio, lighting, staging and technical support for corporate events from one source and deliver nationwide from Manchester, which keeps the coordination on our side rather than yours. Tell us the venue and the shape of the evening and we will say honestly what the room will and will not do. You can reach us through the contact page or by email at hire@eventproductiongroup.co.uk.
