GRAS 40PM EQset™ is the world’s first 1/4-inch pressure-field miniature production line microphone integrated with GRAS proprietary EQset™ built-in DSP equalization technology, developed for automated mass acoustic inspection of consumer audio products including TWS earbuds, Bluetooth headsets, miniature speakers, phone receivers and car audio speakers.

With an industry-standard total length of 34 mm, it supports direct drop-in replacement of legacy production microphones without fixture modification. Each unit is factory-calibrated via DSP with fixed sensitivity and flat frequency response; unit-to-unit sensitivity deviation ≤ ±0.2 dB, and frequency response fluctuation limited within ±0.5 dB up to 10 kHz. It eliminates common pain points of traditional microphones such as individual TEDS parameter entry and production line downtime for recalibration after microphone replacement.