Stereo Equaliser - Focusrite MixMaster Mode D'emploi

- meters display the amount of gain reduction due to compression
GAIN REDUCTION
in each of the three bands. The amount of gain reduction shown on the bargraphs is a rough
indication of how much Make Up Gain (see opposite) will be required to restore the signal to
the original peak level.
- determines the rate at which compression is applied to the signal with increasing
RATIO
input, and is the ratio of change in input level compared to change in output level. For instance
a ratio of 4:1 means that an increase of 4dB in input level will produce an increase of 1 dB in
output level. Higher Ratio settings will produce more noticeable compression, so for the least
obtrusive result the Ratio should be set at the minimum necessary for the application. For
example, using low Threshold and low Ratio will produce a less noticeable effect than a higher
threshold and higher ratio, even though the total amount of compression may be the same.
Note that the Ratio setting will influence the effect of the LF and HF Trim controls (see
"LF/HF Trim" section above).
- the attack rate determines how quickly compression is applied once
SLOW ATTACK
the level of the source signal has risen above the Threshold. The normal setting, with the
switch released, enables the compressor to react relatively quickly to peak levels of the signal. In
some situations, short transients may cause unwanted "pumping" of steadier low level signal
components, and pressing the switch to give a SLOW ATTACK allows the compressor to
ignore short transients and respond more effectively to the average loudness of the signal.
- pressing the Slope switch shifts the crossover point between LF and MF bands,
SLOPE
accentuating the bass sound - great for dance music. The crossover point with the switch in the
downwards 'out' position is at 200Hz. Pressing the switch in moves the crossover point down
to 100Hz. With the switch 'in' an inductor circuit is also introduced into the signal flow,
producing an emphasis peak just below 100Hz, further enhancing the LF content.
- determines how quickly compression dies away once the level of the source
RELEASE
signal has fallen below the threshold. When in the anticlockwise position, the compression
releases very quickly, which may be appropriate on rapidly varying signals to avoid compressing
the beats that follow, but can result in distortion on more sustained material. Slower release
times give a smoother effect, but at the same time may result in transients causing audible
"pumping". Two additional switch positions provide Programme Dependent Fast (PDF) or
Programme Dependent Slow (PDS) release times which respond automatically to the dynamics
of the signal, giving a fast release for transients and a slower release for the average level. The
PDF setting might typically be used for pop tracks, or PDS for classical material.
- adds gain back in to compensate for the gain reduction due to
MAKE UP GAIN
compression. The amount of gain reduction displayed on the bargraph meters will give a useful
guide to the amount of Make Up Gain required.
O/L LED - gives warning of excessive signal levels which may result from the addition of
too much Make Up Gain. The O/L LED thus reads from a point in the circuit immediately
after the compressor section.
- switches the Compressor into the signal path when pressed. The switch illuminates when
IN
pressed to show that the Compressor is active.

STEREO EQUALISER

The stereo 3-band Parametric EQ has stepped frequency shelving high and low bands and a
parametric mid band. The whole EQ circuit is designed to give gentle, musical control
appropriate to the final phase of a mix.
LF / FREQUENCY - the LF control gives 10dB boost or cut at a roll-off frequency of
40, 70 or 120Hz as selected by the FREQUENCY switch. For more gentle control of the bass
content of the mix the TILT
setting selects a 2dB/octave
slope. Selecting 'TILT' allows
subtle control of a broad
range of low frequencies,
starting at 1kHz.
-
MF / FREQUENCY
the parametric mid band has
10dB boost or cut provided
by the MF control, and
centre FREQUENCY
selectable from 100Hz to
10kHz in two ranges.
U s i n g t h e M i x M a s t e r
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