Sound Performance Lab Parametric Equalizer - Manual (Page 15)

15
OPTIMIZER
With proportional-Q the sig-
nal level is dependent of the
bandwidth setting - elimina-
ting the need for constant
level readjustment when
changing the filter settings.
Fig. 3:
Q-values are between 0,2 and
1,5 at maximum boost and
cut of +/- 12dB.
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A AN ND DW WIID DT TH H
""Q Q""
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The Q control sets the bandwidth of the Parametric,
Notch or Band-Pass filters. In the context of the High and
Low-Pass settings, the Q control influences the cut-off cha-
racteristics of the filter. Q is variable from 1.5 to 0.2.
The Q is set to "high Q" (1.5) when turned fully counter
clockwise. The influenced range covers approximately 0.75
octaves. Turning the Q control fully clockwise selects "low Q"
values (0.2) covering approximately 5 octaves.
The OPTIMIZER utilizes the proportional-Q principle,
also known as "variable Q". The amplitude varies depending
on the Q setting. Using low-Q values, automatically readjusts
the amount of boost or cut selected to keep the subjectively
perceived laudness constant. With constant-Q equalizers
there is often only a limited range of useable settings.
Sometimes this is so narrow, you may wonder why the Q
control was not permanently fixed at the point it sounded
really good. Above that position it often starts to sound
harsh and peaky, and below with the broad bandwidth, the
sound is colored so you need to constantly re-set the
boost/cut control. Not so with proportional-Q. The Q control
provides useable settings over the entire range - giving you
more versatility to be creative.
EQ adjustments with proportional-Q sound a lot more
musically related and offer a greater range of possible Q-
choices that really sound good and appropriate
Figure 3 shows curves within varying Q-adjustments but
with constant boost and cut.