The quality of any measurement can only be as good as the instrument used to gather it, and for acoustic measurements, finding a good enough instrument can be surprisingly difficult. Commonly available microphones can be of good quality, but since they are invariably designed for speech or music, they need not have the flat or wide enough response and low noise figure demanded of an instrumentation microphone.
Microphones for measurement purposes can be had for a very large outlay, but here’s [Peter Riccardi] with a unit designed around an array of MEMS capsules that delivers comparable performance for a fraction of the cost.
The result is both an extremely interesting project for those of us with an interest in audio, and a thorough delve into some aspects of its design for those who are merely curious. It uses four capsules in an effort to cancel out induced electrical noise, and boasts some impressive comparative measurements when tested against a commercial measurement microphone. We could almost see ourselves building this project.
Interested in audio technology? Try our Know Audio series.