A matter of opinion

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A matter of opinion
Here's a real mind bender for you. How do engineers verify a microphone's performance? It certainly can't be by listening to its output since microphones don't make sound they only capture it. Playback of a microphone's performance would have to be via a loudspeaker which, of course, has its own sound colorations. No, what they have to do is create a known flat output variable frequency transducer which, as it turns out, is no small feat. The sound generator can't use a speaker so it must be mechanical in nature. Essentially, a motor and a spinning fan. Take a look at this reference sound source. This contraption, in its various forms, generates reasonably precise output levels of sound at varying frequencies. if the designer has access to an anechoic chamber they can generate frequencies and see how the microphone picks them up and converts them into electrical signals. The best Reference Sound Sources I know of are maybe 0.2dB over a narrow band of frequencies and worse outside them. What this means, in a practical sense, is that we don't actually have a good grip on how a particular microphone sounds, certainly not by measurements alone. And if that weren't enough to drive the measurementists nuts, try this one on for size. With few exceptions, microphone testing tells us only two things: how flat and how loud. There is nothing about transient response or phase accuracy. The bottom line is that we have to listen to various microphones to see how they sound relative to what our interpretation of sound is. And the fact we must use our ears and experience as measurement devices means that microphones and their quality are a matter of opinion. Like speakers. Like electronics. Like life.
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Paul McGowan

Founder & CEO

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