Type 4988 - A Mini, Yet Mighty Microphone

To help engineers and acousticians achieve accurate measurements in everyday tasks, Bruel & Kjaer has created a miniature microphone ideal for high-precision acoustic measurements tests within confined spaces – Type 4988-A.

The ¼ inch low noise microphone is optimized for use in pressure-field applications such as use with couplers, measuring close to audio device sound ports or flush-mounting. The microphone also works as a general measurement device when the operator makes use of the inclusive electronics corrections; these include response at different angles of incidence in a free field, corrections in a diffuse field or grid influence.

The microphone has a laser welded diaphragm and is paired to a ¼" Constant Currant Line Drive (CCLD) preamplifier. This connects to CCLD input conditioning, ensuring all measurements meet the industry standard IEEEP1451.4 V1.0.

Type 4988-A’s all-titanium design is highly resistant to corrosion and suitable for a range of acoustic tests, even in the presence of magnetic fields. It’s practically immune to temperature and humidity changes; this extreme stability, combined to a minimal spread in frequency response between individuals (guaranteed ±1 dB from 20Hz to 20KHz), make it ideal for integration in a production line or for general audio measurements.