Most of us are familiar with the idea of volume when it comes to sound. Simply put, the more volume a system has, the louder we percieve the sound to be. Even at a venue with a lavish sound system, we usually hear the spoken word at a moderate, comfortable volume, hopefully as if the orator were standing somewhere near us. Demolition derbies and pep rallies aside, this is the goal. So what is so difficult and warrants so much mystery as the sound system?
Gain is a measurement of difference. In our simplest case, this is the difference between what we’re starting with (the unamplified orator) and what we end up with (the sound throughout the venue). Music concerts have high volume but often little gain. Take the acoustic drum set for instance. It’s very loud to begin with. The sound-tech may jazz it up and make it louder still in the venue, but how much louder? Conversely look at the spoken word in a church. The orator is speaking in a normal voice at a normal volume, but yet it is necessary to hear that quiet source over the rustle of hundreds of feet, hundreds of people breathing (it does add up), and let alone the occasional crying child or sneeze. Add acoustically-irreverent architecture, traffic, and the weather condition of your choice and we end up with a low volume but very high gain application. In essence, because it requires the most gain, the reinforcement of the spoken word is typically the most challenging audio application.
Ironically, there is most likely more sound absorption material at our local hockey arena than exists in all of the churches in Western New York combined.
The appropriate choice of microphone, processing, speaker(s) and alignment is critical to achieving the required amount of gain so that your audience can not only hear but articulate.