Testing, Testing - 1,2,3 - Testing!

In any West End musical the sound design is as important as the lighting or the scenery and a lot of effort goes into making sure that everyone in the audience hears good quality sound. Public Address, or PA as it’s usually known, is an art as much as a science.

The microphone is only part of what’s involved, but it’s essential to capturing the sound in the first place. The sort of robust and chunky mic you see in a rock spectacular - held very close to the performer’s mouth - is designed specially for that job and has different characteristics from one used in a Pavarotti concert. However, they both need to be positioned correctly, shielded from the effects of breath or wind noise and connected to some means of amplifying their electrical signals.

Sometimes, though, the production calls for a more subtle approach, especially for shows like Starlight Express or Barnum where the performer has to be able to move freely around the stage. Usually, a microphone about the size of a grain of rice is taped to the singer’s forehead or face. It’s connected by a very fine wire to a radio transmitter concealed in their costume and that’s how the signal reaches the mixing desk. Although more convenient for the artist, take it from me, radio mics can be a nightmare for the sound man! Quite apart from having to change the batteries in the transmitter regularly, they can also be very vulnerable to the rough and tumble of some productions - and any loose connections cause massive thumps and bangs to appear on the PA speakers. There’s also the problem of interference from other radio transmitters in the same area - on more than one occasion I’ve faded up a radio mic only to hear a taxi responding to a call and on one particularly memorable occasion I managed to pick up the Radio 4 shipping forecast instead of the leading lady! One thing you do need as a sound engineer - like a doctor - is warm hands, because fitting microphones and transmitters inside a performers’ clothing requires a very special rapport…..!

Microphones have to be connected - whether by radio or by cable - to a mixing console which allows them to be combined in the right proportion and in the right sequence so that they can be heard properly. Ideally, the console is positioned where the sound engineer can hear exactly the same thing as the audience. We’re lucky in Ashton Village Hall - our operating position has a good view of the action and you can hear things clearly. Unfortunately it’s also excruciatingly uncomfortable to sit on a small ledge for hours on end!

Signals from the mixing console are amplified and fed to the loudspeakers in the auditorium - and generally the more expensive and more powerful the system the better quality it will be. Our sound system is really only an adapted domestic hi-fi and while it’s OK for general background sounds, it struggles to reproduce music or vocals at a reasonable volume and quality. And as we once convincingly demonstrated, too loud can mean blown speakers! One important job for the sound engineer is to prevent what we call a howl-round - that ear-splitting shriek where the sound from the speaker is picked up by the microphone, shattering the nerves and the ear-drums. It’s caused by a number of factors, including the nature of the acoustics in the theatre or village hall…..and that’s where we came in!