Overview (continued)

Built-in microphones—Pick up sound

Side screen

Microphone cord

Side mesh

FET

Contactor

Microphone casing

Microphone unit

 

Top screen

 

Front grill

Diaphragm

 

Cap

 

Section view of microphone

PCM-D1 incorporates electret condenser microphones that were developed for their high sensitivity and low noise. Unlike tape or disc recorders, PCM-D1 has no drive mechanism and is free of motor noise. This makes it possible to employ a highly sensitive microphone to be used as a component.

All microphone casing parts are cut from metal and fit together nearly seamlessly. Each part is positioned and the front and rear openings are adjusted with 100-micron level precision. Peaks and dips in the microphone’s range are minimized so that

Angle

Figure 1: Built-in microphone, frequency response

acoustic energy is transmitted effectively to the diaphragm in the microphone unit.

To ensure that sound is then converted to electrical signals, the conditions for manufacturing the electret (charging the diaphragm to increase sensitivity to subtle sounds) were reviewed—resulting in a sensitivity nearly 6 dB superior to that of a standard microphone.

In addition, the frequency response of the microphone is improved to nearly –30 kHz, achieving a sampling rate of 96 kHz (Figure 1). This performance is barely affected even when the supplied windscreen is used.

The microphones are positioned using the X- Y pattern and then angled toward each other with the left and right diaphragms close together, thereby covering a wide sound range and reducing phase shifts. The recorded sound has depth and perspective and projects a natural stereo image.

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