| SPECIFICATIONS | 
WL50 
Measured with test circuit (see User Guide) | 
WL50-LO 
Measured with test circuit (see User Guide) | 
MC50 
Measured with RPM626 Preamplifier | 
WL51 
Measured with test circuit (see User Guide) | 
MC51 
Measured with RPM626 Preamplifier | 
| Condenser (electret bias) | 
Condenser (electret bias) | 
Condenser (electret bias) | 
Condenser (electret bias) | 
Condenser (electret bias) | 
Condenser (electret bias) | 
| Polar Pattern | 
Omnidirectional | 
Omnidirectional | 
Omnidirectional | 
Cardioid | 
Cardioid | 
| Output Impedance | 
N/A | 
N/A | 
136 ohms actual (rated at 150 ohms) | 
N/A | 
136 ohms actual (rated at 150 ohms) | 
Recommended Min. 
Input Impedance | 
20 kilohms | 
20 kilohms | 
N/A | 
20 kilohms | 
N/A | 
| Output Level | 
�45.0 dBV/Pa 
(1 Pa=94 dB SPL) | 
�54.0 dBV/Pa 
(1 Pa=94 dB SPL) | 
�41.0 dBV/Pa 
(1 Pa=94 dB SPL) | 
�50.0 dBV/Pa 
(1 Pa=94 dB SPL) | 
�46.0 dBV/Pa 
(1 Pa=94 dB SPL) | 
| Maximum SPL | 
133 dB at 1% THD/ 
20 kilohm load | 
142 dB at 1% THD/ 
20 kilohm load | 
138 dB at 1% THD/ 
1 kilohm load | 
138 dB at 1% THD/ 
20 kilohm load | 
143 dB at 1% THD/1 kilohm load | 
| Frequency Response | 
20 to 20,000 Hz | 
20 to 20,000 Hz | 
20 to 20,000 Hz | 
20 to 20,000 Hz | 
20 to 20,000 Hz | 
| Dynamic Range | 
103.0 dB | 
103.0 dB | 
108.0 dB | 
103.0 dB | 
108.0 dB | 
Output Noise 
(equivalent SPL, A-weighted) | 
30 dB typical; 33 dB maximum | 
39 dB typical; 42 dB maximum | 
30 dB typical; 33 dB maximum | 
35 dB typical; 38 dB maximum | 
35 dB typical; 38 dB maximum | 
| Signal-to-Noise Ratio | 
64 dB at 94 dB SPL | 
55 dB at 94 dB SPL | 
64 dB at 94 dB SPL | 
59 dB at 94 dB SPL | 
59 dB at 94 dB SPL | 
| Power Requirements | 
+5 Vdc on pin 2, return on pin 1 (ground). | 
+5 Vdc on pin 2, return on pin 1 (ground). | 
11 to 52 Vdc (positive on pins 2 and 3, return on pin 1). | 
+5 Vdc on pin 2, return on pin 1 (ground). | 
11 to 52 Vdc (positive on pins 2 and 3, return on pin 1). | 
| Current Drain | 
60�130 µA | 
60�130 µA | 
4.6 mA | 
60�130 µA | 
4.6 mA | 
Polarity�Positive pressure on 
the diaphragm produces a 
positive voltage at: | 
Pin 3 relative to pin 1 at the output connector of the microphone. | 
pin 2 relative to pin 3 of the output 
connector of preamplifier. | 
pin 3 relative to pin 1 at the 
output connector of the 
microphone. | 
pin 2 relative to pin 3 of the output 
connector of preamplifier. | 
| Overvoltage Protection | 
N/A | 
N/A | 
+/- 75.0 Vdc maximum from pins 
2 and 3 to pin 1. | 
N/A | 
+/- 75.0 Vdc maximum from pins 
2 and 3 to pin 1. | 
| Cap and Overmold Material | 
Polypropylene | 
| Environmental Conditions | 
Operating Temperatures: �18 to 57 degrees C (0 to 135 degrees F) 
Storage Temperatures: �29 to 74 degrees C (�20 to 165 degrees F) 
Humidity: 0 to 95% | 
| Packaged Weight | 
188 g (6.63 oz.) | 
188 g (6.63 oz.) | 
305 g (10.76 oz.) | 
188 g (6.63 oz.) | 
305 g (10.76 oz.) | 
| Cable and Connector | 
1.5 m (5 ft.), small-diameter, 
shielded, with miniature female 
4-pin connector (TA4F type). 
WL50X: 3 m (10 ft.) 
small-diameter, shielded, with 
stripped and tinned leads. | 
1.5 m (5 ft.), small-diameter, 
shielded, with miniature female 
4-pin connector (TA4F type). 
WL50X�LO: 3 m (10 ft.) 
small-diameter, shielded, with 
stripped and tinned leads. | 
1.5 m (5 ft.), small-diameter, 
shielded, with miniature female 
4-pin connector (TA4F type). | 
1.5 m (5 ft.), small-diameter, 
shielded, with miniature female 
4-pin connector (TA4F type). 
WL50X: 3 m (10 ft.) 
small-diameter, shielded, with 
stripped and tinned leads. | 
1.5 m (5 ft.), small-diameter, 
shielded, with miniature female 
4-pin connector (TA4F type). | 
Microphone and Preamp 
Dimensions | 
See User Guide | 
| Net Weight | 
WL50: 21 g (0.7 oz.) with cable 
and connector. 
WL50X: 28 g (1.0 oz.) with 3 m 
(10 ft.) stripped and tinned 
cable. | 
WL50�LO: 21 g (0.7 oz.) with 
cable and connector. 
WL50X�LO: 28 g (1.0 oz.) with 
3 m (10 ft.) stripped and tinned 
cable. | 
121 g (4.3 oz.) with cable, 
connector, and preamplifier. | 
WL51 21 g (0.7 oz.) with cable 
and connector. WL51X: 28 g 
(1.0 oz.) with 3 m (10 ft.) 
stripped and tinned cable. | 
121 g (4.3 oz.) with cable, 
connector, and preamplifier. |