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PolarFlex(TM) Mic by Schoeps

Author
장호준
Date
2008-06-08 08:07
Views
1336

PolarFlex(TM)

 




PolarFlex(TM)
– System for Modeling any Microphone

Make
the recording first and then choose the microphones...

  • two output
    channels
  • emulates
    the sound of any microphone
  • offers many
    new creative possibilities for shaping the sound of a recording
  • frequency
    response and polar pattern can be tailored
  • the characteristics
    of the recording microphones can be chosen after the recording
    (post-processing in the digital domain)
  • digital and
    analog inputs and outputs
  • analog-style
    controls
  • user preference
    settings can be stored and recalled
    space.gif

dsp-polarflex.gif

DSP-4P
processor

 

dsp-kfm-rear.gif

rear
panel of the processor

 


Condenser microphones
of the same nominal directional pattern often sound quite different
from one another. Differing on-axis frequency response explains
only part of the sonic impression; equally important is the fact
that polar patterns vary throughout a microphone's frequency range,
and that they do so differently in different types of microphone.
The lack of constancy in polar response is technically a defect,
but realistically such defects can be used to advantage when adapting
to the acoustics of a particular recording environment.

Equalization
can be used to control the effective frequency response of a microphone.
Until now, however, there has been no direct way to alter polar
patterns in a corresponding manner, i.e. separately within specific
frequency ranges. With the DSP-4P processor, nearly-ideal (i.e.
frequency-independent) directional characteristics can be selected
– or nearly any frequency-dependent directional characteristic
can be chosen, e.g. a “cardioid“ which becomes omnidirectional
below the midrange so that it has better response at the very lowest
frequencies.

The DSP-4P can
model well-known microphones (e.g. the behavior of large-diaphragm
microphones can readily be synthesized), but its most interesting
application may be to optimize a recording by defining characteristics
that do not exist in any real-world microphone of today. In an excessively
reverberant space one could obtain a “drier” sound (cardioid
or supercardioid setting) or in spaces that are dry, one could accept
more room reflections (wide cardioid or omni setting) – either
across the bandwidth or in a particular frequency range. The ratio
of direct to reflected sound would thus be altered rather than the
on-axis frequency response. That cannot be done with an equalizer
– nor can a reverb unit reduce the degree of reflected sound
in a recording after it has been made.



The PolarFlex(TM)
microphone system consists of:

  • a pressure
    transducer (omni) and a figure-8 per channel (also two cardioids
    per channel can be used)
  • the
    DSP-4P stereo processor

On the
right, two suitable double microphone arrangements are shown.
They both are made up of SCHOEPS microphones and accessories.

The upper
arrangement (omni + figure-8) consists of:

  • An
    omnidirectional microphone with a mild high-frequency emphasis
    in the direct sound field (shown here: CCM
    2SLg
    ). Because of its angle of orientation, the capsule
    has ideal directional response in the horizontal plane.
    The high-frequency emphasis compensates for the high-frequency
    losses due to lateral sound incidence.
  • A
    figure-8 microphone (CCM
    8Lg
    ) set directly above the omni; the direction in which
    it is aimed will determine the orientation of the resulting
    adjustable “virtual” microphone. The hemispherical
    device attached to the top of the figure-8 flattens the
    response of the omnidirectional microphone at the highest
    frequencies.

 

polarflex-dtm-e.jpg" height="519" width="245" alt="polarflex-dtm-e.jpg" />

The second arrangement
consists of an X/Y stereo microphone, the SCHOEPS CMXY
4V
. The two cardioids have been rotated to an included angle
of 180°, and are aimed forward and backward.

Other small-diaphragm
condenser microphones can also be used. They must be small-diaphragm
microphones, however, since only those would have a sufficiently
uniform directional characteristic throughout the frequency range.
If another kind of microphone is used, the result could be uncontrolled
polar response at various frequencies. If the first arrangement
(shown on top) is being followed, the figure-8 microphone should
have flat frequency response, while the omni should have a slight
diffuse-field equalization (a high-frequency emphasis as measured
on axis).

Processor
The following settings can be made independently of one another
in three adjustable frequency ranges. With the three knobs in the
upper row, the directional patterns in each of the three frequency
bands can be set. The settings are indicated by a circle of LEDs
around each of the knobs. At the lower left of each knob is the
omnidirectional setting; at the lower right is the figure-8 setting.
Eleven intermediate pattern settings are available. The knobs in
the lower row are set between those in the upper row. They are used
for setting the boundaries between the frequency ranges: 100 Hz
– 1 kHz and 1 kHz – 10 kHz respectively, in third-octave
steps.

If the unprocessed microphone signals have been recorded, these
adjustments can be made after the recording during post-processing.

The three buttons at the lower right are for storing and recalling
presets.

The processor operates at 24-bit resolution with either a 44.1,
48 or 96 kHz sampling rate (switchable). When a digital device is
connected to the input, the PolarFlex(TM)
processor adapts to its clock signal.


The PolarFlex(TM) is offered as a complete
set, including:

DSP-4P processor
including mains cable and a polished wood case

CCM 2S Lg
(omni)

CCM 8 Lg (figure-8)


The two pairs of CCM are selected and matched. They are delivered
with adapter cables K
5 LU
(Lemo/ XLR-3M), stand adapters SGC and a polished wood
case.

2× KA DTM hemispherical cap for CCM 8

2× B-DTM microphone bars

1× traverse bar for mounting two “PolarFlex” microphones
with B-DTM bar on a common microphone stand in various simple stereo
setups

2× KLY-DTM Y-cable for connecting each microphone pair via
KS 5 IU adapter
cable

2× KS 5 IU, extension cable for the Y-cable KLY-DTM, 5 m long,
Binder miniature plug to XLR-5M

AK SU/2U
adapter cable (XLR-5F to 2× XLR-3M) for the analog outputs
of the processor

Optional accessories:
XLR-5 extension cables for the microphone pairs (two would be needed
for the four microphones):

KS 10 U, KS 20 U,
KS 30 U (10, 20 and 30 m long)

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