1/2” Random Incidence, Mid to High Frequency & Amplitude, Prepolarized Microphone

Model 377A21 (cartridge) and Model 378A21 (cartridge and preamplifier system) are used in diffuse field applications and measure the entire human audible range and beyond. Accurate response is provided where high frequencies need to be measured precisely.

The 378A21 is an industry exclusive, ½” random incidence response microphone system that measures beyond 20 kHz, the maximum frequency of the human hearing range. It has a flat response in diffuse field applications where high frequencies need to be measured very accurately in the presence of acoustic reflections.  The 378A21 has the ability to measure to 25 kHz (±2 dB) and to 150 dB in a cost effective ½” package, while maintaining a 22 dBA noise floor. It avoids overload seen when a standard high sensitivity (50 mV/Pa) microphone measures over 136 dB.

Acoustic pressure waves may be altered by objects in the sound field including the microphone used to measure it. To correct for this effect, the 377A21 random incidence microphone is calibrated to compensate for its presence. This provides more accurate measurements within a diffuse field.