 
                         
                        Boundary Layer Microphone
GFM 132
Neumann’s first and only boundary layer microphone. The GFM 132 was designed using computer simulations: The unique shape of the base plate avoids comb filter effects.
| Diameter | 213 mm | 
|---|---|
| Length | 168 mm | 
| Weight | 460 g | 
| Current consumption (P48, IEC 61938) | 2 mA | 
| Directional Pattern | Hemispherical | 
| Frequency Range | 20 Hz ... 20 kHz | 
| Matching connector | XLR 3 F | 
| Rated Impedance | 50 Ohms | 
| Supply voltage (P48, IEC 61938) | 48 V ± 4 V | 
| Acoustical operating principle | Pressure transducer | 
| Maximum output voltage | 10 dBu | 
| Rated load impedance | 1000 Ohms | 
| Maximum SPL for THD 0.5% | 137 dB | 
| Equivalent noise level, A-weighted | 14 dB-A | 
| Sensitivity at 1 kHz into 1 kohm | 18 mV/Pa | 
| Maximum SPL for THD 0.5% with preattenuation | 147 dB | 
| Signal-to-noise ratio, CCIR (re. 94 dB SPL) | 70 dB | 
| Signal-to-noise ratio, A-weighted (re. 94 dB SPL) | 80 dB | 
| Signal-to-noise ratio, CCIR (re. 94 dB SPL) | 70 dB |