SCHOEPS KFM 360 - Manual (Page 4)

4
Overview
picked up.
If the unprocessed microphone signals are
recorded (four channels), the effective direc-
tional settings can be chosen retroactively
during post-production playback.
The center channel signal is derived from
the front channels by a matrix. An additional
channel contains only a low-frequency signal
up to 80 Hz, which is obtained by summing
the pressure transducer outputs and reduc-
ing the total level by 6 dB.
To prevent the disturbing effect of rear-chan-
nel localization of sound sources, the rear
channel signals can be reduced in level,
delayed and/or processed by an adjustable
low-pass filter.
In addition to these primary functions, each
selector switch also has a secondary func-
tion that allows, for example, the relative
front-to-back channel gain or the left/right
balance to be adjusted. While recording
there is also a monitoring function which
permits twelve different signals to be heard
through Output III, as determined by the set-
ting of the REC MONITOR knob.
Suggestions concerning microphone
placement
The KFM 360’s microphones pick up both
level and arrival-time differences between
the left and right channels. However, the
diameter of the KFM 360 has been made
smaller than that of the sphere stereo micro-
phone KFM 6 in order to increase the stereo
pickup angle. This is because a surround
microphone will often be placed closer to
the sound source than a microphone might
be for conventional stereo pickup. The rear-
channel loudspeakers will reproduce com-
ponents of the diffuse sound field, thus giv-
ing an impression of the hall’s spatial char-
acter. This reduces the difficulty of finding a
microphone position that will provide both a
clear stereophonic image and also a good
balance of direct and reverberant sound.
+
−
+
−
+
−
+
−
front channels:
sum (omni + figure-8)
rear channels:
difference (omni - figure-8)
right front
(R)
right surround
(RS)
omni omni
figure-8
CCM 8
figure-8
CCM 8
Derivation of right front (R) and right surround signals (RS)
as proposed by Bruck (rough diagram)
KFM 360