The Shure WH20 is a rugged, lightweight, dynamic headset microphone that provides high-quality voice pickup. It fits securely for active microphone users, such as aerobics instructors and musicians, with low visibility for stage appearances.
The cardioid (unidirectional) pickup pattern provides greater gain-before-feedback and isolation from ambient noise and other unwanted sound sources. A carefully shaped frequency response includes a voice-frequency presence peak and a low-frequency roll-off to compensate for the proximity effect inherent in cardioid mics during close-talk operation.
Impedance
Rated at 150 ohms (200 ohms actual)
Output Level (close talked* at 1,000 Hz)
Open Circuit Voltage: . . . . . . . . . . . . . . . . . . . . . . . . . . -67.0 db/Pa (0.45 m)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Pa = 94 dB SPL
*At 12.5 mm (1/2 inch)
Hum Sensitivity
38.4 dB equivalent SPL in a 1 millioersted field
Polarity
WH20QTR as a wired microphone: Positive sound pressure on diaphragm produces positive
voltage on tip with respect to sleeve (ground) of microphone output phone plug
connector.
WH20QTR, WH20TQG used with Shure Wireless Systems:
1/4-inch Phone Jack Receiver Outputs: Positive sound pressure on diaphragm produces
positive voltage on tip of receiver output connector.
3-pin XLR Receiver Outputs: Positive sound pressure on diaphragm produces positive
voltage on pin 2 with respect to pin 3 of low-impedance output connector, and on tip of
Aux output connector.