Dual MEMS microphones within 53 mm passive amplifier:
Dual MEMS microphones without using a passive amplifier:
Dual track recording:
Left channel: Dual MEMS microphones within 53 mm passive amplifier.
Right channel: Dual MEMS microphones without using a passive amplifier.
Original playback speech samples used to make recordings:
Power spectral analysis of: "Track17-24at4meterWith23dBAdded.mp3" (first 237.8 seconds).
Dual MEMS microphones shown photographed on top of a mirror so as to make both microphones visible. Port openings face each other on opposite sides of a 1 mm printed circuit board. The sum of 2 coherent audio signals increases the signal level by 6 dB. Self-noise from 2 microphones is incoherent and uncorrelated and consequentially these noises will only increase 3 dB within the resulting signal summation.
53 mm soft silicone passive amplifier shown next to a pen for scale. Port openings of dual MEMS microphones are positioned at interior apex of passive amplifier.
Representation of raw audio data recording: "Track17-24at4meterWith23dBAdded.mp3" (first 237.8 seconds). - Top signal trace represents: left channel dual MEMS microphones within a 53 mm passive amplifier.
- Bottom signal trace represents: right channel dual MEMS microphones without a passive amplifier.
White Paper: Hear the Far-Field Audio Differences (pdf)