Learn Hiring and planning

Hiring an acoustic consultant

What a proposal for a room’s acoustics and sound system should contain, what to insist on, the red flags, and what the work costs in Lisbon.

We are consultants ourselves; this is the advice we would give you if you were hiring someone else.

Start with a written scope

Before you speak to anyone, write down what the space is for: how many people, what they will listen to, whether there is a DJ or live music, the hours, how loud it should get, who lives or works next door, what cannot change, and what you can spend. Then send the same scope to every consultant you ask, so that their quotes can be compared line by line.

A request like this one suits most small venues. Change what does not fit yours.

Please quote for a site survey and room-acoustic assessment of our space, for up to how many people; a complete sound-system design, with speaker positions and the reasoning for their coverage and SPL; an itemised bill of materials, with at least one approved alternative where appropriate; a cable schedule and a signal-flow diagram; support in getting and comparing installers’ quotes; one review during installation; and on-site measurement, DSP tuning, limiter setup and a handover to staff.

Please quote any sound-isolation or environmental-noise assessment separately, and say whether accredited testing or licensing documents will be needed. For each phase, please give a fixed fee, the number of visits and revisions included, whether IVA and travel are included, and any margin or commission you would earn on equipment.

The deliverables checklist

Tick these off against any proposal. A feasibility audit needs only a few of them, and a quiet café may not need them all; but if one your project needs is missing, ask for it, or for a lower price.

    Insist on these in a proposal

    • A fixed fee for each phaseWith named deliverables, and an hourly rate for anything outside them. The number of visits, meetings and rounds of revisions stated.
    • Acoustic targets in numbersRT60 by octave band, a limit for background noise, a target for speech intelligibility where speech matters, and the level the room will run at.
    • System targets in numbersCoverage, predicted SPL, frequency range, headroom, where the subwoofers go, and how loud it may get for the audience.
    • The software named, and the plots suppliedWhere the design is modelled, the tool it was modelled in, such as EASE, EASE Focus, Soundvision, ArrayCalc or a speaker maker’s own, and the plots themselves. For a small room, calculations fit for its size are enough.
    • IndependenceNo commissions you have not been told about. If the consultant also sells equipment, the margin is disclosed and the design fee is kept separate.
    • At least two equipment optionsWherever one brand is not technically required.
    • Files you can usePDFs, and the editable CAD or vector originals of any drawings.
    • A commissioning procedureWho brings the measuring equipment, who sets the DSP and the limiters, and what happens if the result does not match the prediction.
    • IVA and travelStated as included or not.

    Red flags

    • No named deliverablesA “consulting package” with no list of documents and no drawings.
    • A free design that ends in one brand’s quoteThat is sales, not consultancy. A free first visit to see whether a project makes sense is fine.
    • Foam for the neighboursAcoustic foam everywhere, offered as the answer to noise complaints: why that fails.
    • No numbersNo measurements, no RT60 figures and no prediction plots: only a promise that it will sound great.
    • Nobody tunes itThe installation handed over without anyone tuning the DSP, or with the DSP left open for anyone to change.
    • Silent substitutionsAn installer swapping specified equipment without your written approval.
    • A complete plan at a dealer’s price

    Pay for the tuning

    In a small room, small errors are easy to hear: a speaker mounted a little too low, one aimed at the bar, a subwoofer out of phase with the main speakers. A modest system, well tuned in a treated room, can sound better than an expensive one installed by eye.

    So ask for at least one commissioning visit, in which the consultant measures the installed system, sets its alignment, EQ and limiter, and tests every source, and for the report that shows what was measured and set.

    What it costs