M 149
The M 149 Tube* is a variable dual-diaphragm microphone. The K 49 capsule – well-known from the legendary U 47 and M 49 microphones – is followed by a tube functioning as an impedance converter. In contrast to earlier concepts – utilizing a transformer – the tube is complemented with a transformerless output circuit design. The M 149 Tube can thus feed long microphone cables without any coloration.
Two slide switches are located below the large, acoustically very open headgrille. The switch at the front allows selection one of nine directional patterns. The slide switch at the rear operates a seven-step high pass filter. It allows a very fine adjustment of the cut-off frequency.
Technical Data
| Acoustical operating principle | Pressure gradient transducer |
| Directional pattern | Omnidirectional, wide angle cardioid, cardioid, hypercardioid, figure-8 plus one intermediate position each |
| Frequency range | 20 Hz … 20 kHz |
| Sensitivity at 1 kHz into 1 kohm | 34/47/62 mV/Pa1) |
| Rated impedance | 50 ohms |
| Rated load impedance | 1 kohms |
| Equivalent noise level, CCIR2) | 28/25/23 dB1) |
| Equivalent noise level, A-weighted2) | 16/13/11 dB-A1) |
| Signal-to-noise ratio, CCIR2) (rel. 94 dB SPL) | 66/69/71 dB1) |
| Signal-to-noise ratio, A-weighted2) (rel. 94 dB SPL) | 78/81/83 dB1) |
| Typical SPL (tube characteristic)3) | K < 0,5 %: 120 dB, K < 5 %: 136 dB |
| Maximum output voltage | 18 dBu |
| Dynamic range of the microphone amplifier (A-weighted) for < 0,5% THD (for < 5% THD) | 101 (121) dB |
| Powering | Power supply N 149 A |
| Matching connectors | Microphone DIN8F, Power supply XLR3F |
| Weight | 730 g |
| Diameter | 70 mm |
| Length | 201 mm |
