The Neumann U 89 i nickel large-diaphragm condenser microphone is a versatile studio microphone. The protective grille houses a dual-diaphragm capsule and a rotary switch beneath the grille allows selection of five different directivity patterns.

The amplifier handles sound pressure levels up to 134 dB without distortion. This value can be increased to 140 dB. An additional rotary switch activates a filter that modifies the low-frequency response below 80 Hz or 160 Hz.

This microphone offers omnidirectional, cardioid, figure-8, hypercardioid and wide-angle cardioid characteristics. Compared to the standard cardioid directivity, the hypercardioid characteristic suppresses lateral sounds more effectively. The wide-angle directivity is particularly useful for recording large sound sources.

The microphone is front-addressing. The large-diaphragm capsule exhibits a very linear frequency response for all directivity patterns over a wide acceptance angle. The frequency response curves are flat up to 10 kHz within a capture angle of ± 100°. The U 89 i has a very uniform diffuse-field response for all directivity patterns. This is important in a reverberant environment when more reflections reach the microphone capsule. The acoustic information is not affected in its tonal quality when recorded by the microphone. This characteristic is achieved without resorting to corrective resonance effects. The capsule is elastically mounted to prevent any structure-borne noise that could interfere with its operation.

The amplifier handles sound pressure levels up to 134 dB without distortion. With a self-noise level of 17 dB (A-weighted), the total dynamic range is 117 dB. The maximum sound pressure level is 140 dB when the -6 dB rotary switch is in the ON position.

A high-pass filter at 80 Hz or 160 Hz can be activated with another rotary switch beneath the grille. This filter suppresses low-frequency interference while maintaining a linear frequency response for close sound sources. A steep high-pass filter in the LIN position prevents the microphone output transformer from being overloaded by unwanted subsonic frequencies.

All exposed surfaces of the microphone capsule, including the diaphragms, are at earth potential. This makes them highly resistant to electrical and atmospheric interference and to contamination by microscopic dust particles.

- Variable large-diaphragm microphone

- Pressure gradient transducer with dual-diaphragm capsule

- Omnidirectional, wide-angle cardioid, cardioid, hypercardioid and figure-8 characteristics

- Two-stage high-pass filter

- Switchable 6 dB pre-attenuation