Nigel Williams
Commercial Director, ProAudium
Nigel Williams has been a director of ProAudium since 2014. ProAudium maintains and services emergency sound systems across London and the South East.
He learnt the work on sites that could hardly be more different: stadia, shopping centres, office blocks, ships, oil rigs and theme parks.
His work now covers what happens to a voice alarm system after it is installed. That includes maintenance to BS 5839-8, systems at large venues under BS 7827 and the Guide to Safety at Sports Grounds, and the emergency voice communication systems covered by BS 5839-9. The articles here come from that work. Each one starts from a question that came up on site or in a quotation and works it through against the standard. Every clause is cited so you can check it for yourself.
He also builds the free tools on this site: the standby battery calculator, the Zone Output Estimator and the Martyn's Law checker.
Articles
What is PAVA?
One sound system doing two jobs: everyday announcements, and emergency voice messages that override everything else.
Fire follows physics. An attacker reads your procedure.
Message libraries are built for fire, which never reads the plan. Why the emergency microphone is a venue's primary control, and who keeps it ready.
100 V line explained: why the amplifier's power ends up in the loudspeaker, not the cable
Why 100 V line exists, worked through 20 m of Cat 5e: 40 % of the amplifier's power lost in the cable, or 0.4 % on 100 V line.
Peukert's law oversizes your voice alarm batteries
The number hidden in the usual equation, and the line at 20 Ah.
Attention please: the two worst words to start an emergency announcement
The words that open almost every UK emergency announcement came bottom of eight in the study that ranked them.
What battery manufacturers should publish, but do not
The 30-minute discharge figure the calculation needs, and who publishes it.
The worked example that doesn't work
The arithmetic error in BS 5839-8:2023 Annex C, traced term by term.
Your next voice alarm battery quote should be smaller than your last
What the 2023 edition changed, and three questions to ask before you sign.
Questions about an article, or about a system of your own? Contact Nigel.