The work of systems designers, front of house and monitor engineers, systems engineers, sales engineers, and probably several other job descriptions, can include any number of cumbersome test and measurement tools and instruments. But when all we need are quick, rough estimates, there are several easy ways to get reasonable answers with nothing but the human body and an awareness of how it’s applied.
Here, I’ll detail my on-board kit. I hope you find one or more of these tools makes your work a little quicker and easier. They have for me.
Consistent On Pitch
Ever wish you had perfect pitch? I don’t, but I do have really good relative pitch. By this I mean I can’t easily tell what note or chord is being played, but I can hear when some instrument or person is out of tune by as little as 5 cents, or 5 percent. The word “cent” stands for one hundredth of an equal-tempered semitone, and because there are 12 semitones in one musical octave, one octave consists of 1,200 cents.
Why does this matter? Where and when does good relative pitch become useful?
During rehearsal or sound check, it’s appropriate (IMHO) to help musicians and singers know when there are pitch issues that can be corrected but have yet to be recognized. Of course, you need to be consistently right. Then grace, tact and humility are required for your comments to be well received and appreciated. Believe it or not, when everyone’s pitch is locked in, your mix will sound better. (If you want to test your own ability, try the Intonation Ear Trainer game here.)
How low can you whistle? This next one won’t be much help if you can’t whistle, but I’ll presume you can pull off a basic, lip-pucker whistle. I stumbled onto this one about 25 years ago when I got my first spectrum analyzer and have re-verified the concept with my (Rational Acoustics) Smaart rig multiple times.
The lowest tone I can whistle is an extremely consistent 500 Hz, +/- 25 Hz or so. Weird, I know, but very helpful. It’s so consistent that I’ve won a few lunch bets when I tell people I can pick, or produce, 1 kHz out of the air. I simply start with my lowest whistle tone, and then move up 1 octave. (If you struggle hearing an octave interval in your head, think about the first two notes in the chorus of the song “Somewhere Over the Rainbow.”)
This whistle trick comes in quite handy when trying to pick out feedback frequencies. I’m sure no one can whistle between 40 Hz and 16 kHz, but applying a little simple math, and an understanding of musical scales and octaves, goes a long way toward making this work.
As a sound tech, it’s really helpful if you have some basic understanding of musical notation, scales and intervals. All you really need is the knowledge and ability to whistle a major scale between the lowest frequency you can whistle, and the next one or two octaves above. In musical terms, C5 is very close to 500 Hz, so I’ll use that to help explain how to translate musical scales into sine wave frequencies.