background image

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

Содержание DSP-4 KFM 360

Страница 1: ...DSP 4 KFM 360 Digital Microphone Processor for Surround System with KFM 360 Sphere Microphone Operating Instructions...

Страница 2: ...nels 15 F REAR BALANCE REAR DELAY ms REAR SLOPE ms The low frequency channel 15 Monitoring 15 Storing and loading presets 16 Synchronization 17 Specifications 18 Important notices 19 Warranty 19 Subje...

Страница 3: ...rear channel microphones is independently selectable the stereo basis width of the front chan nels is independently variable adjustable time delay and low pass filtering for the rear channels sampling...

Страница 4: ...als 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 diffe...

Страница 5: ...Block Diagram 5 Signal processing flow in the DSP 4 KFM 360 MODE B SURR In the REC mode the equalization for omni and figure 8 is not active...

Страница 6: ...use the DSP processor as a microphone preamplifier together with its A D converter KFM 360 left yellow mark 1 3 2 4 right red mark channels front A red dot indicates the front of the figure 8 red mar...

Страница 7: ...t For processing the signals this control must be set to B which is the case when any pair of LEDs lights up Signals at the analog outputs XLR 5 Signals at the digital outputs left 1 3 2 4 right chann...

Страница 8: ...ion control deter mines whether you are using the function settings of the first green layer or the sec ond red layer Only the settings in the cur rently selected layer will be changed The center chan...

Страница 9: ...Quick Start 9...

Страница 10: ...ht Number of the current preset Function control determines the set of func tions of the five selector switches Pushbuttons for selecting a preset Pushbutton for stor ing the current set tings as the...

Страница 11: ...converters Slave AES EBU switches over to the digital inputs Analog outputs SURR mode B REC mode A Output I channel 1 left front left omni channel 2 right front right omni Output II channel 1 center...

Страница 12: ...mpartment out To facilitate changing the fuse unfold the small tabs that are on either side of the fuse holder When the proper value fuse has been inserted turn the fuse holder so that the intended vo...

Страница 13: ...e of the analog inputs Input pair I KFM 360 input pair II the two figure 8s A four channel recorder will use both the master and the slave input sockets The processor will thus receive word clock from...

Страница 14: ...e DSP 4P At any given moment they display the highest level occurring anywhere within the signal pro cessing system The 3 dB LED should light only during the highest peak inputs i e only very rarely O...

Страница 15: ...es The 3 dB point of the low pass filter is 80 Hz It is critically damped with a fourth order rolloff 24 dB octave Monitor function REC MONITOR In recording mode MODE A REC the input signals are passe...

Страница 16: ...presets 0 through 9 Please note The groups of stored set tings include the position of the five main knobs in their primary functions all of which are controlled in the green mode FRONT pattern FRONT...

Страница 17: ...l outputs left left right left right left right right Master Master How to synchronize two DSP 4 KFM 360 or a DSP 4 KFM 360 DSP 4P PolarFlex processor with one recorder If it should be necessary to sy...

Страница 18: ...CIR 113 dB RMS A weighted 110 dB RMS unweighted Characteristic impedance of the cables which are connected to the digital outputs 110 Ohm AC mains voltage switchable 110 120 V 220 240 V Power consumpt...

Страница 19: ...turer accepts full responsibility for this declaration Warranty We guarantee our products for a period of twenty four months except for cables bat teries and cells including rechargeable bat teries an...

Страница 20: ...070509...

Отзывы: