First listening to some tracks, and later mixing a live worship band, I came to the conclusion that the reason the system worked was due to signal to noise ratio.
What I was hearing in the coverage area was significantly more direct sound than reflected sound.
Additionally, with the reverberant field being relatively full frequency – and with a smooth decay – the “noise” of the reverb was not obnoxious.
So the next time that you’re working with sound reinforcement in a room that has loud air-handling noise, remember that you’ll need more signal than noise. Simple, right? Well, not so much.
The noise is at a constant level and the program material (spoken word and music) is not.
Another way to think of it is to look at another signal to noise situation: what happens when the pastor is preaching and someone’s cell phone goes off. The noise (the cell phone) interrupts the signal (the preaching) and turns into a distraction.
Take the same situation except that the preacher is replaced by a worship band measuring in at 85 dBa. The cell phone goes unnoticed (probably even by the owner) as the signal (the band) is louder than the noise.
Note here the obvious, that the band it playing at a relatively consistent level and there are now musical breaks in the music.
So what solutions do we have?
1) Design worship spaces with minimal external noise influence (air handling, street traffic, sound from adjacent rooms, and so on).
2) When noise can’t be contained or the room was not designed properly, get as much direct energy as possible to the listeners. (But be reasonable – 110 dBa is most likely not reasonable.)
3) Charge an extra tithe to anyone whose cell phone goes off during a service. (Am I kidding?)
It really comes back to designing worship spaces to work well for the varying elements of worship, as well as working from the outset to keep as much noise out of the space as possible.
Gary Zandstra is a professional AV systems integrator with Parkway Electric and has been involved with sound at his church for more than 25 years.