MPA461 1/4” Free-field Microphone Set
MPA461 is a combination of MP401 microphone and MA411A/B preamplifier, which can be separate into MP401 and MA411A/B according to user’s application.MP401 is a 1/4" free-field microphone, suitable for measurement in free-field and semi free-field without reflection. It is prepolarized microphone without external polarization voltage and suitable for ICCP-powered preamplifier. It is complying with IEC 61094 WS2F standard.
MA411A/B is a 1/4" ICCP-powered preamplifier, suitable for prepolarized microphones
Optional TEDS is available for most of BSWA preamplifier to support read microphone information directly by data acquisition equipment, including microphone model, serial number, sensitivity, etc. BSWA TEDS microphone supports the IEEE 1451.4 standard. The v0.9 version is used by default to be compatible with more data acquisition equipment. The v1.0 version can also be selected according to user’s requirements.
Features:
● 1/4” free-field
microphone
● Sensitivity (@250 Hz):
5 mV/Pa (-46 dB re 1V/Pa)
● Frequency response: 10 Hz ~ 40 kHz (±2
dB),
● Dynamic range: 35 dBA ~
155 dB
● Polarization voltage:
0V (prepolarized)
● Pressure equalization:
rear-vented
● Optional TEDS
(IEEE.1451.4)
Applications:
● High precision general
purpose acoustic measurement
● About
The Microphone Set
The output impedance of the working
standard microphone can reach more than GΩ level, so it cannot be directly
connected to the data acquisition equipment. The preamplifier must be used to
reduce the output impedance to below 100 Ω. The traditional condenser
microphone also needs the preamplifier to provide an external polarization
voltage of 200 V to charge the capacitor, or coat the rear plate with electret
material that can store charge to replace the polarization voltage
(prepolarized).
Anyway, different microphone types need to
be matched with corresponding preamplifiers to work. BSWA offers the microphone
set that consists of microphone cartridge and preamplifier, is reliable and
robust. The microphone set is assembled in a clean-room environment, reducing
the potential measurements errors cause by the interface contaminating.
● Compatibility
BSWA MK series external polarization
microphone needs to be matched with MV series traditional 200 V preamplifier
and MC7xx series conditioner; while MP type prepolarized microphone need to be
matched with MA series ICCP preamplifier and MC1xx series conditioner. The
connection thread between the microphone and the preamplifier complies with WS2
(1/2”) or WS3 (1/4”) standard, and the same type of microphone or preamplifier
can be connected to each other.
● Preamplifier’s
Impact
The preamplifier not only reduces the
output impedance, but also has a certain impact on the performance of the
microphone, as described below:
1. Sensitivity:
Preamplifier always lowers the sensitivity of the microphone. The typical
attenuation value is about 0.3 dB.
2. Self-generated
noise: The output noise of the microphone is thermal noise, and the
preamplifier will bring a certain amount of electrical noise. Therefore, the
total output noise of the combination of microphone and preamplifier is the sum
of thermal noise and electrical noise.
3. Maximum
output voltage: The maximum output voltage of the microphone is the product of
its maximum sound pressure level and its sensitivity. This value often cannot
exactly match the maximum output voltage of the preamplifier. The maximum
output voltage of the combined microphone and preamplifier is determined by the
smaller of the respective maximum output voltages of the microphone and
preamplifier. Therefore, if the maximum output voltage of the preamplifier is
smaller than the maximum output voltage of the microphone, the dynamic range of
the microphone will be reduced.
4. Frequency
response: The MA series ICCP-powered preamplifier has certain attenuation at
low frequency, but it can still meet the general requirements from 20 Hz to 20 kHz.
Specifications
Specification | |
---|---|
Diameter | 1/4" |
Standard (IEC 61672) | Class 1 |
Microphone | MP401 |
Sound Field | Free-field |
Preamplifier | MA411A/B (with TEDS) |
Open-circuit Sensitivity (mV/Pa) (±2 dB) | 5 (-46 dB re 1V/Pa) |
Frequency Response (Hz) | 10 ~ 40 k (±2 dB), 6.3 ~ 50 k (±3 dB) |
Dynamic Range (dBA ~ dB) | 35 ~ 155 |
Maximum Output Voltage (Vp) | ±8 |
Self-generated Noise (dBA) | 35 |
Output Impedance (Ω) | < 30 |
Pressure Equalization Vent | Rear vented |
Power Supply | ICCP (2mA ~ 20mA, 4mA Typ.) |
Operating Temperature Range (°C) |
-30 ~ 80 |
Operating Humidity Range (%RH) |
0 ~ 95 |
Temperature Coefficient (250 Hz) (dB/°C) | -0.02 |
Pressure Coefficient (250 Hz) (dB/kPa) |
-0.007 |
Influence of Humidity (dB) |
<0.1 |
Dimensions (mm) |
Ø7 × 63.3 (with MA411A), Ø7 × 58.3 (with MA411B) |
Output Connector |
SMB / 10-32 UNF |
Weight (g) |
7.7 |
TEDS Version |
IEEE 1451.4 compliant (default v0.9, optional v1.0) |
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