Meyer Sound Laboratories, Inc.
2832 San Pablo Avenue
Berkeley, CA 94702
Operating Instructions
CP-10S
Complementary
Phase
Parametric
Equalizer
Center Frequency
Control
The tunable filters in the CP-10S each have a 10:1 fre-
quency range. Any frequency between 20 Hz and 20 kHz
may be selected for equalization, and the overlap between
filters is such that any frequency between 60 Hz and 6 kHz
can be selected in two filters per channel. This degree of
versatility and precision is most useful when equalizing
resonances that are both narrow in bandwidth and closely
spaced in frequency.
When two filters in the same channel are tuned to the
same frequency, the combined effect is dependent on the
amount of boost of cut selected in each filter and the
bandwidths chosen. When the same center frequency and
bandwidth are chosen, the net effect of the two filters will
be approximately two-thirds of the sum of the boost or cut
of the filters when inserted separately. If a filter is set to
0 dB of boost or cut, then it should be removed from the
signal path using the In/Out switch. This will prevent any
interaction with adjacent filters tuned to the same fre-
quency.
Bandwidth Control
Each of the tunable filters can be adjusted from a minimum
bandwidth setting of 0.1 octave to a maximum of 1.1 oc-
taves. The Bandwidth Control is continuously variable
between these extremes. In combination with the Center
Frequency and Boost/Cut Controls, the Bandwidth Control
makes it possible to complement exactly a resonance or
response peak in order to remove the resonance and
flatten system response.
Boost/Cut Control
The Boost/Cut Control for each of the tunable filters in the
CP-10S is continuously adjustable from 15 dB of Boost to
15 dB of Cut. In the center, the Boost/Cut Control will have
no appreciable effect on the signal unless another filter in
the same channel is tuned to the same frequency. In this
case, the amount of boost or cut available in the active filter
is reduced. It is recommended that filters not in use be
bypassed using the In/Out switch.
High and Low Shelving
Cut Filters
In addition to the tunable filters described above, there are
two shelving cut filters per channel, each with its own
control. The high and low shelving cut filters are so de-
scribed because as each is turned from flat response to
maximum cut, the turnover frequency shifts and the slope
steepens. This provides the user with a flexible tool for
house-curve tailoring or bandwidth limiting. Using the
shelving cut filters at maximum attenuation reduces the
bandwidth of the equalizer to approximately 3 octaves
between 5 kHz and 500 Hz, with a filter slope of 6 dB per
octave above and below those frequencies.
50
100
200
500
1k
2k
5k
10k
20k
Amplitude, 3dB per division
A set of equalization curves showing symmetry at 10 dB boost
and cut (minimum and full bandwidth settings included).
50
100
200
500
1k
2k
5k
10k
20k
Amplitude, 3dB per division
Frequency in Hertz
Frequency in Hertz
A set of equalization curves showing action of high and low
shelving cut filters, from flat to maximum attenuation.
