Sound Performance Lab Parametric Equalizer - Manual (Page 5)

5
OPTIMIZER
The Optimizer comprises four
identical filter stages which
can be configured for 4-band
mono, dual
2-band mono or 2-band ste-
reo operation.
Each filter covers the same
enormous frequency range
10Hz to 23kHz.
Each filter has its own mode
switch, so complex combina-
tions of filter types can be
used in the same signal path.
changing the filter settings. When broadening the band-
width, the boost or cut will be reduced proportionally, so
that the subjectively perceived loudness remains constant.
The proportional-Q principle operates according to the way
our hearing system perceives sound.
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 sounds 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 con-
stantly 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.
The Optimizer comprises four identical filter stages
which can be configured for 4-band mono, dual 2-band
mono or 2-band stereo operation. The front panel Dual
switch selects between 4-band or dual 2-band operation.
Both balanced XLR and unbalanced jacks are provided for
signal connections to and from the Optimizer. In Mono
mode, the filters are all connected in series, but the outputs
from each pair of filters remain accessible, so you can get
two differently filtered versions of the same signal which can
be useful when you are creating special effects.
Each filter covers the frequency range 10Hz to 23kHz in
four switched frequency ranges to give fine frequency con-
trol, regardless of which part of the audio spectrum is under
process. Tuning the equalizer is very intuitive because the
frequency control law has been designed to match the cha-
racteristics of the human hearing system.
Being able to equalize starting at 10Hz with full
boost/cut power gives a new dimension for mixing and pro-
ducing of subwoofer-compatible soundtracks.
The frequency response of the circuitry used in the audio
signal path exceeds the limits of human hearing by a consi-
derable margin, effectively eliminating undesirable phase
shifts which, even when relatively small, can seriously
impair the high frequency transparency of a less well-desi-
gned equalizer.
Each filter has its own mode switch to select between
High-pass, Low-pass, Band-pass and Parametric modes. In
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