PA Mythology

by David Cottle d.cottle at utah dot edu

I've made my peace with the audio world. When I hear an awful sounding PA I just bite my tongue; audio engineering is a personal thing, and you can't feel responsible for a bad mix. But sometimes it seems to me that engineers, callers and musicians are casting sea shells, burning candles and incense; doing things that make no sense only because they heard somewhere that you should do it that way. I offer here to dispel a few of the common myths I see around sound reinforcement.

The disclaimer: My opinions come from experience, not formal education. I've never studied audio engineering. But I have worked on both sides of the microphone (as a musician and engineer) for nearly fifteen years. I was an engineer at the University of Illinois, director of the electronic music lab at Brigham Young University, and now direct a small digital studio at a fine arts academy. Engineers tend to be very deeply invested in their way of doing things, and you're sure to find ardent believers in the following myths.

  1. The sound engineer controls the volume and mix.

    The musicians and caller have much more control over how the PA sounds than does the engineer. Five inches closer or farther at the mic translates into as much as 6 db (most faders only range 10) over the PA. You also affect the clarity of the sound and amount of bass with mic axis (where the diaphragm of the mic is pointing) and distance. The engineer usually tries to maintain control by telling you not to move or change your position. This is because he assumes you don't know what you're doing. If you do know what you are doing you can have a lot of effect on the sound. My favorite mixes are those where I leave the faders flat and the musicians mix themselves by leaning into or out of the mic depending on the mix they want.

  2. Professional musicians need monitors.

    Don't get me wrong; monitors are a great addition to a PA, but they are too often used more to reassure amateurs that they are important. Professional musicians learn to work without them. For example, have you ever seen a monitor for the fifth chair violin stand in an orchestra? It's not that they don't want to, or can't hear the flute, they have just learned how to use their ears. Even with all that timpani and brass going on, you can learn to sift through it. One of the jazz bands I worked with refused to use a PA. I played acoustic guitar. The fifth trumpet could hear me because he knew how to listen. Likewise, it's not hard to sift through the chaos of a contra dance in order to hear the guitarist sitting next to you.

  3. A talented engineer turns the knobs a lot.

    If an engineer is futsing around with the knobs and it still sounds OK then it's more likely because the musician knows how to use the mic (see myth one), has a quality instrument (which generates a good sound source to begin with) and whoever bought the PA insisted on quality equipment in the first place. These three rules of thumb tend to make up for the boy/toy urge we all have when faced with rows of buttons.

  4. Signal processors improve the sound.

    Signal processing (eq, reverb, compression) compensate for bad equipment and inexperienced musicians/engineers. Signal processing, by definition, compromises the original signal. At the University of Illinois we had stacks of signal processors. We rarely used them. We did work very hard at getting quality recordings, but it involved mic choice and placement, not signal processing.

  5. Every instrument should be heard.

    When I played with the jazz band, my instrument was not always discernible to listeners, but that's OK, because I was contributing to the ensemble sound. On the other hand, callers and lead instruments should always be discernible. Rhythm instruments should be felt. When quiet instruments (bass or dulcimer) need to be heard, rather than turning them up, the other instruments should lay out.

  6. If you can't hear, you should turn it up.

    Raising the volume of the PA so people can hear is treating a symptom, not the problem. The problem is usually too much interference (talking from the hall) or a caller that doesn't speak clearly or project. Removing interference from the hall is the best solution. We've all experienced the situation where a caller leaves the mic to do a demonstration on the floor. Everyone hushes to hear the call. Isn't it curious that the only time everyone in the hall can hear everything the caller says is when s/he is not using the PA? The second solution is to use the mic better. Some people are shy about a mic and play or speak quietly, but projection is still useful when using a PA. You should speak and play as if you aren't using sound reinforcement. You've probably noticed during the group announcements at a dance how you can hardly hear one person (everyone yells at the engineer to turn it up, s/he jumps at the chance to fiddle with a knob) then the next person nearly knocks the windows out. This is not the engineers fault. The second person just knows how to use a mic on axis and project.

  7. It has to sound unnatural (amplified, processed, brighter than normal) to be heard.

    There is a school of engineering that says you should accent those frequencies that pierce through everything else. But speech uses a very wide band of frequencies and if you accent one band, the PA will still sound loud (that frequency will be loud), but you won't be able to understand because that frequency is distracting you from all the other parts of the spectrum. Even response is best. Engineers don't like even EQ because then they can't play with the knobs.

  8. Every instrument needs a mic and all dances require a PA.

    It's hard to imagine, these days, a single instrument on stage performing without a PA, isn't it? But it happened (and still happens) all the time. Most instruments were built to fill a crowded hall. Pianos, in particular, usually don't need a mic. Many contra situations don't require a PA at all. Musicians can usually generate a lot more sound than they do. I recently attended an intimate concert in a space about the size of a large living room. The acoustics were great. There were twenty people in the audience, four musicians. They were setting up a PA. It was absurd.

  9. High cost = best sound.

    Actually this is true. But you need to consider an extremely steep diminishing return. In most contra situations the difference between a $130 dynamic and a $2,000 condenser will be recognized by only 1% of the dancers. Spend the money on good gear, but be reasonable.

  10. More gear = best sound.

    Audio gear never improves sound quality. It just amplifies it. Worse yet, it compromises it, then amplifies the compromised signal. A speaker will never sound like a cello because they are made differently. Cellos radiate, speakers project. Every extra piece of audio gear in the chain will compromise the sound.

Some rules of thumb:

And when you hear poor engineering, bite your tongue and grit your teeth (not at the same time).

Provided by the New England Folk Festival Association