Last Updated: 20050909, tendeloo
T16 - Fundamental Knowledge about Microphones
Presenter:
Jörg Wuttke, SCHOEPS GmbH - Karlsruhe, Germany
Abstract:
Even a professional with many years of experience might enjoy reviewing the basics of acoustics and the operating principles of microphones. This tutorial also includes a discussion of technical specifications and numerous practical issues.
- Introduction: Vintage technology and the future; physics and emotion; choosing a microphone for a specific application
- Basic acoustics: Sound waves; frequency and wavelength; pressure and velocity; reflection and diffraction; comb filter effects; direct and diffuse sound
- Basic evaluations: Loudness and SPL; decibels; listening tests; frequency/amplitude and frequency/phase response; frequency domain and time domain
- How microphones work: Pressure and pressure-gradient transducers; directional patterns; some special types (boundary layer microphones and shotguns)
- Microphone specifications: Frequency responses (plural!); polar diagrams; free-field vs. diffuse-field response; low- and high-frequency limits; equivalent noise, maximum SPL and dynamic range
- Practical issues: Source and load impedance; powering; wind and breath noise
