M 661+A 802
- 1/2inch, Free-field, 16kHz, IEPE
The M 661+A 802 is an IEPE 1/2-inch prepolarized free-field measurement microphone, which is used to measure the undistorted true sound pressure of the microphone before it is placed into the sound field.
Description
Specifications
| Parameter | Value |
|---|---|
| TEDS Function | No |
| Dimensions | 1/2inch |
| Sound Field Type | Free field |
| Polarization Voltage | 0V(Pre-polarized) |
| Frequency Response | 3.15Hz – 16kHz ± 2dB 12.5Hz – 10kHz ± 1dB |
| Dynamic Range | 18dB(A)-135dB(1000 Hz 失真<3%) |
| Noise Floor | <18dB(A) |
| Sensitivity | (50±10)mV/Pa (-26.0± 2)dB re 1V/Pa |
| Maximum Output Voltage | 5.6V |
| Output Impedance | <50Ω |
| Supply Power | 2mA - 10mA(Typical4mA) |
| Pressure Equalization Method | Post-equalization |
| Connector Type | BNC |
| Operating Temperature | -30°C to 85°C |
| Temperature Coefficient | -0.012dB/℃ |
| Humidity Coefficient | <0.1dB(0-90% no condensation) |
| Relative Humidity | 0-90% no condensation |
| Static Pressure Coefficient | -0.01dB/kPa |
| Storage condition | Temperature: 25℃±5℃, humidity: 50%±15%RH (to ensure the long-term stability of the sensor) |
Specifications
Types of Acoustic Fields | Free Field |
Polarization voltages | 0V(Prepolarized) |
Frequency range | 3.15Hz – 16kHz ± 2dB 12.5Hz – 10kHz ± 1dB |
Dynamic range | 18dB(A)-135dB(1000 Hz THD<3%) |
Background noise | <18dB(A) |
Sensitivity | (50±10)mV /Pa (-26.0± 2)re 1V/Pa |
Maximum Output Voltage | 5.6V |
Output Impedance | <50Ω |
Power Supply | 2mA - 20mA(typical 4mA) |
Pressure Equalization Method | Post-equalization |
Connection | BNC |
Operation temperature range | -30℃ to 85℃ |
| Temperature range coefficient | -0.012dB/℃ |
Storage condition | Temperature:25℃±5℃,Humidity:50%±15%RH(Ensure the long-term stability of the sensor) |
| RH | 0 - 90% no condensation |
Humidity coefficient | <0.1dB (0% - 90% no condensation) |
| Static pressure coefficient | -0.01dB/kPa |
Typical frequency response curve

Dimensions
Overall length | 85mm |
Diarmete | 13.2mm |
Diameter (excluding protective grille) | 12.7mm |
Preamplifier mating threads | 11.7mm - 60UNS |

The measuring microphones we produce are precision sensors, and all aspects related to production are strictly controlled, including material selection, production processes, testing control, and production environment.
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![]() We adopt advanced production processes and fully automated precision machining equipment, which significantly reduces the accuracy errors caused by secondary clamping in traditional machining equipment. This greatly enhances the dimensional consistency, geometric accuracy, and overall quality stability of the products, providing reliable technical support for demanding application scenarios. |
![]() At the same time, we employ extremely rigorous testing and control measures, conducting quantitative testing on any links that may lead to product quality issues, and implementing test sequence control to prevent skip-station situations. The comprehensive MES control enables all data to be traceable, ensuring a high degree of consistency in sensor quality. |
The entire production process of all our microphones is strictly carried out in a dust-free workshop, which can minimize the amount of dust in the air, thus creating a stable and pure working environment for the sensors. This ensures a long and stable lifespan for the sensors and maintains their excellent performance throughout daily use. |







