Neumann USM 69 i Stereo microphone

Stereo Recording Made Easy

The USM 69 i is a one-point stereo microphone for all coincident stereo techniques
such as XY, MS, and Blumlein. Each of the two large diaphragm capsule systems has
its own pattern selector with 5 positions; the upper system can be rotated over a range of 270°.
The USM 69 i can also be used in mono with two directional characteristics simultaneously.

One Point Stereo Microphone

Stereo recording with two separate microphones can be cumbersome. Especially with coincident
stereo setups, where the two capsules must be placed very close to each other at a defined
angle to ensure precise imaging. The Neumann USM 69 i one point stereo microphone makes such
coincident stereo recording techniques very easy.

Two in One

The USM 69 i has two separate dual diaphragm condenser capsules, mounted vertically,
which may be rotated against each other over an angle of 270°. The polar pattern of each
capsule can be selected individually using two built-in rotary switches. Each capsule has its own
head amplifier feeding separate pins of the XLR 5 output connector. The USM 69 i, thus,
is two independent microphones in one convenient package. As it requires only one microphone
stand, the USM 69 i is very easy to re-position for optimal results.

With five polar patterns available for each capsule – omni, wide cardioid, cardioid, hypercardioid,
and figure-8 – the USM 69 i allows for MS and XY stereo techniques in all variations, including Blumlein.
Thanks to its low self-noise of 13 dB-A and its high SPL capability of 132 dB, the USM 69 i may be
placed freely for best sound and imaging, with no worries about excess noise or distortion.
An active subsonic filter protects the output transformers from overload due to structure borne noise.

Applications

The USM 69 i is an excellent stereo microphone for any musical applications such as vocal and instrumental ensembles,
drums overheads, large instruments such as grand piano and harp, as well as solo instruments when stereo width and
spatial movement is desired to enhance the listening experience. The USM 69 i is also a superb microphone for
radio drama, and audio book productions with a sound similar to the acclaimed standard for spoken word, the Neumann U 87 Ai,
but adding a stereo perspective.

Additional Uses

Apart from stereo applications, the USM 69 i may also be used to record a mono source with two different
polar patterns simultaneously. Since both microphones inside the USM 69 i work completely independently,
it can serve as its own backup microphone in high reliability situations. If one side fails or is
inadvertently disconnected, the other side remains unaffected. Even in the rare event that DC converter for
the capsule bias fails, the USM 69 i remains operational; both systems will automatically select
the cardioid pattern and continue to work with just a slightly reduced sensitivity.

    Stereo microphone for XY and MS stereophony
    Two large diaphragm capsules with separate pattern selection
    Five polar patterns
    Upper capsule rotates against the lower capsule over 270°
    Very low self-noise

Acoustical operating principle  Pressure gradient transducer
Directional 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, CCIR 1  24 dB
Equivalent noise level, A-weighted 2  13 dB-A
Maximum SPL for THD 0.5% 3  132 dB
Signal-to-noise ratio, CCIR (re. 94 dB SPL) 4  70 dB
Signal-to-noise ratio, A-weighted (re. 94 dB SPL) 5  81 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  XLR 3 F
Weight  510 g
Diameter  30 + 48 mm
Length  293 mm