Neumann USM 69 i Neumann

USM 69 I

Compact switchable stereo microphone for MS and XY stereophony, with freely adjustable pickup angles and selectable directional characteristics.

The USM 69 i stereo microphone has two separate dual-diaphragm capsules. These are mounted vertically and rotate against each other. The directional polar patterns can be selected separately for each capsule. The capsules operate independently from each other.

Applications

The USM 69 i condenser stereo microphone is a studio microphone for intensity stereo recording. It is suitable for XY and MS recordings.

Construction

The microphone consists of the amplifier section and the capsule head. The amplifier section contains two microphone amplifiers operating independently from each other. They have an extremely low self noise.

Two completely separate microphone capsules are positioned closely above each other within the capsule head. Their diaphragms are made out of gold-sputtered polyester film. The upper capsule rotates against the lower one over a range of 270°. Color markings on the lower capsule system help to identify the angle by which the upper capsule has been rotated.

When sound waves reach the microphone capsules from different directions they will generate audio signals with different intensity only, but not with time differences, since the capsules are in close proximity and the sound arrives at both capsules simultaneously. The result is an intensity stereo signal that can be summed together for excellent mono compatibility without causing interference.

Polar patterns

The USM 69 i has two built-in rotary switches. The five polar patterns of both capsules can be selected at the microphone itself. Therefore, no special AC power supply units or powering adapters are necessary.

The two outputs attach directly to any 48 V phantom powered connectors.

In addition to the usual polar patterns: omnidirectional, cardioid, and figure-8, we have added a hypercardioid and a wide-angle cardioid pattern.

A built-in DC converter generates the required capsule polarizing voltages.

Electrical features

The amplifiers feature high output capability and extremely low self noise. Distant sound sources, as well as very loud sound sources at close range can therefore be recorded without any problem.

Each amplifier has an active filter. It effectively suppresses subsonic interference as caused by wind or structure borne noise. At the same time, the filter prevents the output transformers from overloading through very low frequency energy.

Use as a mono microphone

The microphones may also be used as completely independent mono microphones. There are many applications when it is important to have a second mono microphone as a backup, or when the outputs of microphones with different polar response characteristics must be available simultaneously.

The outputs of the two microphone channels can be linked (cascaded). In addition to the individual directional patterns, other characteristics are available through the combination of both channels.

Operational safety

Both microphone systems operate completely independent from each other.

The second amplifier will be unaffected, even in case of a faulty ground of the supply voltage for one of the channels, or a short circuit in one of the outputs.

The microphone is reliable in mono usage, even if only one of the systems is operated and connected. Its simple and redundant circuitry guarantees a low failure rate.

Should the DC converter ever fail, a diode circuit within the microphone ensures that both systems will remain operational. The cardioid pattern is automatically chosen. The sensitivity is reduced by 3 dB.

 Features

 

Switchable stereo microphones

Two pressure-gradient transducers with double membrane capsules

MS- or XY-stereophony

Capsules rotary by 270°

Very low noise

Aperture and pick-up angles freely choosable

Directional characteristics reproducably switchable, omni, wide angle cardioid, cardioid, hypercardioid, figure-8

 

Technical Data

Acoustical operating principle	Pressure gradient transducer
Direct ional pattern	Omnidirectional, wide-angle cardioid, cardioid, hypercardioid, figure-8
Frequency range	20 Hz … 20 kHz
Sensitivity at 1 kHz into 1 kohm	13 mV/Pa
Rated impedance	150 ohms
Rated load impedance	1 kohms
Equivalent noise level, CCIR1)	24 dB
Equivalent noise level, A-weighted1)	13 dB-A
Signal-to-noise ratio, CCIR1) (rel. 94 dB SPL)	70 dB
Signal-to-noise ratio, A-weighted1) (rel. 94 dB SPL)	81 dB
Maximum SPL for THD 0.5%2)	132 dB
Maximum output voltage	3 dBu
Supply voltage (P48, IEC 61938)	48 V ± 4 V
Current consumption (P48, IEC 61938)	2 x 0.7 mA
Matching connector	XLR5F
Weight	510 g
Diameter	30 + 48 mm
Length	293 mm

 

______________________________________________ 1) according to IEC 60268-1; CCIR-weighting acccording to CCIR 468-3, quasi peak; A-weighting according to IEC 61672-1, RMS 2) measured as equivalent el. input signal

 

Accessories

Adapter Cable AC 20
Adapter Cable AC 22
Adapter Cable AC 25
Adapter Cable AC 27
Auditorium Hanger MNV 87 (mt)
Battery Supply BS 48 i-2
Boom Attachment M 212 c
Floor Stand MF 5
Microphone Cable IC 5 (mt)
Microphone Cable IC 6 (mt)
Popscreen PS 15
Popscreen PS 20 a
Power Supply N 248
Stand M 210/1
Stand M 214/1
Stand M 252
Stand Extension STV 4/20/40/60
Table Stand MF 3
Table Stand MF 4
Vertical Bar MZEF 8060/8120
Windscreen WS 69