The Neumann U 89 i black large-diaphragm condenser microphone is a studio microphone for multiple applications. The head grille protects a dual-diaphragm capsule and a rotary switch beneath the head grille allows selection from five different polar patterns.

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

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

The microphone is front-addressed. The large-diaphragm capsule has a very smooth frequency response for all polar patterns over a wide acceptance angle. The frequency response curves are flat up to 10 kHz within a pickup angle of ± 100°. The U 89 i has a very uniform diffuse-field response for all polar 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 head grille. This filter removes low-frequency interference whilst maintaining uniform frequency response for close sound sources. A steep high-pass filter in the LIN position prevents the microphone's 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 contamination by microscopic dust particles.

- Variable large-diaphragm microphone

- Pressure gradient transducer with dual-membrane capsule

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

- Two-stage high-pass filter

- Switchable 6 dB pre-attenuation