Neumann|纽曼 U 87 Ai 大振膜电容话筒带3种可切换指向
发布时间:1970-01-01编辑:DanceSmile阅读()
A Well-Deserved Reputation as the Best!
Arguably the best known and most widely used studio microphone in
the world (for good reason), the easy-to-recognize U 87 is a
classic! A distinctive design and legendary Neumann sound make this
mic a must-have for pro studios. The U 87 is known for its unique
frequency and transient response characteristics which deliver a
smooth natural sound with a variety of source material.
Applications
The U 87 Ai condenser microphone is a
large diaphragm microphone with three polar patterns and a unique
frequency and transient response characteristic. Users recognize
the microphone immediately by its distinctive design. It is a good
choice for most general purpose applications in studios, for
broadcasting, film and television.
The U 87 Ai is used as a main
microphone for orchestra recordings, as a spot mic for single
instruments, and extensively as a vocal microphone for all types of
music and speech.
Acoustic
features
The U 87 Ai is addressed from the
front, marked with the Neumann logo. The frequency response of the
cardioid and figure-8 directional characteristics are very flat for
frontal sound incidence, even in the upper frequency range. The
microphone can be used very close to a sound source without the
sound becoming unnaturally harsh. By means of a highpass filter
interferences through subsonic and low frequencies are reduced
remarkebly.
Polar
patterns
The dual-diaphragm capsule is
elastically mounted and protected by a large headgrille. A switch
below the headgrille selects the three directional patterns:
omnidirectional, cardioid and figure-8. A window above this switch
shows the symbol of the selected characteristic.
Electrical
features
The letter A in the name indicates a
more recent generation, as compared to the U 87 i microphones that
were built from 1967 to 1986. Modifications apply to the electronic
components of the microphone only; the capsule remained
unchanged.
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 10dB for identical sound pressure
levels, and an improved S/N ratio of 3dB.
Filter
and attenuation
A switch located at the rear
attenuates the sensitivity by 10dB. When this switch is activated,
the microphone accepts sound pressure levels up to 127dB
(equivalent to a sound pressure of 45 Pa) without distortion. 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.
Neumann
U 87 Ai Features:
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 10dB pre-attenuation
Ideal as main and as support microphone in the most differing
recording situations