 Boundary-Layer Microphones
Boundary-Layer Capsule
BLM 3g
- microphone capsule (pressure transducer) designed
for placement at an acoustic boundary layer
- highly uniform
hemispheric directional pattern; when the pickup angle
changes, the sound “color“ does
not change
- excellent reproduction of low frequencies
Boundary-layer recording is a well-known technique by
now, offering unobtrusive microphone placement possibilities
(no stands or hanging fixtures required, and it is not
necessary to aim the microphone) and a directional characteristic
that is independent of frequency.
It is based on an effect in physics by which sound pressure
doubles along a sound-reflecting surface. If a transducer
is placed upon (or within) a large, sound-reflecting surface,
its output voltage will be twice that of an equivalent
transducer in a free sound field.
Dimensions: plate: 200
mm × 200 mm × 5 mm
Height of the microphone-amplifier connector: 21 mm
Weight: 570 g (without microphone amplifier)
Surface finish:
matte gray
Accessory for BLM 3g (optional):
Upper illustration:
Special clamp MS-BLM allowing Mid-Side (M/S) stereo pickup
with the BLM 3g in the Mid channel
Lower image shown with
Setup for M/S:
recordings with BLM 3g + MS-BLM and MK 8 + KC Active Cable
or Compact Microphone CCM 8U
Miniature Boundary-Layer
Capsule
 BLM 03 Cg
- pressure transducer with hemispherical pattern
- active miniature version of the BLM 3g
- unobtrusive,
universally applicable
The BLM 03 Cg offers all the recognized advantages of
the BLM 3g, while its smaller size permits more unobtrusive
microphone placement. Its shallow profile and circular
shape can often be disguised or hidden, e.g. under a light
tablecloth. It is recommended in those cases where the
BLM 3g is too large (e.g. for TV or film sound) or too
heavy (e.g. for mounting in the interior of a car under
the roof, or beneath the lid of a piano).
An Active Cable hard-wired to the BLM 03 Cg allows it
to be joined to any microphone amplifier of the Colette
Series (except the battery-operated model CMBI) to become
a complete microphone. The Active Filter CUT may also be
added.
It should be noted that any boundary-layer microphone
must be placed on a sufficiently large sound-reflecting
surface for adequate low-frequency pickup. For speech applications
as, for example, when a conference is to be recorded, a
table top may be sufficient, but most music recordings
will require the use of a larger surface.
Dimensions:
diameter: 80 mm, max. height: ca. 8.6 mm
Cable length: 5 m
Weight without microphone amplifier CMC:
233 g
Surface finish: matte gray |
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