The U 87 is equipped with a large dual-diaphragm capsule with three directional patterns: omnidirectional, cardioid and figure-8. These are selectable with a switch below the headgrille.
A 10 dB attenuation switch is located on the rear. It enables the microphone to handle sound pressure levels up to 127 dB without distortion.
Furthermore, the low frequency response can be reduced to compensate for proximity effect.
The present-day circuitry increases the operational headroom of the U 87 Ai by supplying the bias voltages for the capsule through a reduced resistance. The result is a higher sensitivity of 10 dB for identical sound pressure levels, and an improved S/N ratio of 3 dB.
An additional switch at the rear allows to change the microphone's cutoff frequency. This reduces low frequency interference directly at the input of the microphone amplifier.
This setting also compensates for the unavoidable bass boost that occurs with all pressure gradient transducers when they are used at close distance (proximity effect).
The cardioid characteristic maintains a smooth frequency response at a distance of 30 to 40 cm, the figure-8 characteristic even at a distance of 15 to 20 cm.
- Variable large diaphragm microphone
- Pressure-gradient transducer with double membrane capsule
- The studio microphone classic
- Three directional characteristics: omni, cardioid, figure-8
- Switchable low frequency roll-off
- Switchable 10 dB pre-attenuation
- Ideal as main and as support microphone in the most differing recording situations
Acoustical operating principle: Pressure gradient transducer
Directional pattern: Omnidirectional, cardioid, figure-8 plus
Frequency range: 20 Hz ... 20 kHz
Sensitivity at 1 kHz into 1 kohm: 20/28/22 mV/Pa
Rated impedance: 200 ohms
Rated load impedance: 1 kohms
Equivalent noise level, : 26/23/25 dB
Equivalent noise level, A-weighted: 15/12/14 dB
Signal-to-noise ratio, CCIR (rel. 94 dB SPL): 68/71/69 dB
Signal-to-noise ratio, A-weighted (rel. 94 dB SPL): 117 dB (cardioid)
Maximum SPL for THD 0.5%: 17 dB (cardioid)
Maximum SPL for THD 0.5% with preattenuation: 127 dB
Maximum output voltage: 390 mV
Dynamic range of the microphone amplifier (A-weighted): 105 dB
Supply voltage (P48, IEC 61938): 48 V ± 4 V
Current consumption (P48, IEC 61938): 0.8 mA
Matching connectors: XLR3F
What's in the box
- Microphone U 87 Ai MT
- Wooden Box