Symetrix 601, Руководство пользователя

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4-4
Rev 2.2, 10/31/94
4.4.2 EQ Parameter Group
The switches in the parameter group modify the settings of the selected (flashing) parametric
EQ section. Each switch has the following action:
F
REQ
(
K
H
Z
)
The Wheel modifies the center frequency of the
selected equalizer from 31 Hz to 21.11 kHz.
Holding down the
F
REQ
switch allows setting the
time constant for the rate of change of the center
frequency. Shares time constant (
rt ) with
W
IDTH
switch. The filter frequencies are 1/10th octave
ISO standard frequencies except for some special
power line harmonic frequencies at the low end.
L
EVEL
(D
B
)
The Wheel modifies the amount of boost or cut
from +18 dB to -50 dB.
The display indicates the filter's boost/cut setting
in dB. The display reads
out when no filter
contribution has been set (same as
L
EVEL
at
0/out). Holding down the
L
EVEL
switch allows
setting the time constant for the rate of change; the
display reads
rt . This affects how quickly the
LEVEL setting changes either due to MIDI
command, program change, or rotation of the
Wheel.
W
IDTH
(O
CT
)
The Wheel modifies the bandwidth from 0.05-
octaves (very sharp or narrow) to 3-octaves (quite
broad). The rate-of-change value is shared with
and accessed with the
F
REQ
switch since both are
frequency-related parameters.
4.5 Dynamics Processing Block
The dynamics processing block encompasses the de-esser, dynamic noise reduction (NR),
downard-expander, compressor, and AGC. Whenever one of the
dynamics processors has been selected for edting, the output LED
display changes to a gain-reduction display
Note: All of the dynamics blocks use a threshold parameter.
Unlike analog processors that you may be familiar with, each
of the threshold settings in the 601 reference to digital
clipping (full-scale) rather than to some nominal signal level
(like 0 dBu). This means that you may not be able to directly
translate threshold settings that you are familiar with from the analog world to the digital
world.
4.5.1 Dynamic Noise Reduction Block
The dynamic noise reduction (NR) block uses a variable frequency low-pass filter to perform
single-ended noise reduction. The NR block is a feedback system; the amount that the filter
'opens up' is self-limiting and dependent on the high-frequency content of the input signal and
the
T
HRESH
old setting. At higher
T
HRESH
old settings, there will always be some high-frequency
loss.
F
ATTACK(mS)
DYNAMICS PROCESSING
COMPRESS
RATIO(X:1) AGC
FREQ(kHz) /
THRESH(dB)
RELEASE(mS) DS
B)
NR
EXPANDER