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Microphone [GA116E]
ACO ½“ Electret Condenser Microphone Cartridge Type 7146. Microphone
reference point is the centre of the diaphragm.
Type MK75 (ACO 7146)
Specification
Diameter (inch)
0.5
Response Type
Free-Field
Polarization (V)
0.0
Frequency Range (Hz)
10 - 20000
Sensitivity (mV/Pa)
50.0
Sensitivity (dB re 1V/Pa)
-26.0 ±1.5dB
Capacitance (pF)
18.0
Max. Sound Pressure Level (dB)
146.0
Temperature Coefficient (dB/°C)
-0.01
The pressure to free-field correction value to be applied when used with a Castle
calibrator GA601/GA607 or B&K4231 is as follows:
-0.2dB
The capsule can be removed by unscrewing anti-clockwise although great care
must be taken when doing this to avoid damage to either the capsule or the
instrument. Re-fitting is a reverse of the above.
Type MK75 (ACO 7146) Typical Microphone Response
16Hz
0.0
1kHz
0.0
31.5Hz
0.0
2kHz
0.0
63Hz
0.0
4kHz
-0.1
125Hz
0.0
8kHz
-0.7
250Hz
0.0
16kHz
1.0
500Hz
0.0
Typical Actuator to free field correction factors(dB) of an MK75
(ACO 7146) microphone (Based on 500Hz = 0)
250Hz
0.0
2.5kHz
1.0
315Hz
0.0
3.15kHz
1.2
400Hz
0.0
4kHz
1.5
500Hz
0.0
5kHz
2.0
630Hz
0.0
6.3kHz
2.5
800Hz
0.0
8kHz
3.8
1kHz
0.0
10kHz
4.6
1.25kHz
0.2
12.5kHz
6.8
1.6kHz
0.4
16kHz
8.8
2kHz
0.5
20kHz
10.0
