McIntosh MQ108 Owner's Manual page 11

CAPACITOR
Capacitor A
in Microfarads
Capacitor B
in Microfarads
Preferred capacitors are metalized polyester or equivalent, and should have a voltage rating
of 50V or higher.
CAPACITOR INSERTION and EQUALIZATION ADJUSTMENT
Two pairs of capacitor connecting pin sockets are provided for each equalizer section,
marked A and B. It is not necessary to observe the polarity of the electrolytic capacitors.
For example, select the narrow filter at 31.5Hz as the first band of equalization in the left
channel. Insert a 1.0 capacitor into the 1L, A connecting sockets. Insert a .18 capacitor in
the 1L, B connecting sockets. Both capacitors must be inserted for proper performance. Select
and insert capacitors for the next frequency to program on the left channel in the 2L connect-
ing sockets. The first frequency to be programmed for the right channel should have capacitors
inserted in the 1R connecting sockets. When capacitors are in place for each frequency and
channel to be equalized, the level controls must be adjusted to the desired degree of boost
or cut. At this point, make an initial setting of the HIGH FREQUENCY COMPENSATION con-
trols to simulate which type of overall response curve desired, (A, B, or C).
To determine the results of the equalizing process, the response must be checked again
with the analyzer. If you are using an analyzer with a continuous display, the controls may
be adjusted and results seen immediately. If you are using an analyzer that indicates with
a meter, the controls must be set in an intermediate position and the results plotted on a
graph. After plotting the first response curve, you can then determine the need for further
adjustments by running another response curve. This procedure should be repeated until you
arrive at the response desired.
Depending on whether a wide or narrow band is used, and how much amplitude is pro-
grammed will affect the overall shape of the resulting response curves. It is possible for the
response curves of two nearby frequencies to overlap. Readjustments must often be made
with repeated response measurements until the final desired result is achieved. The HIGH
FREQUENCY COMPENSATION controls will be valuable in setting the desired high frequency
slope to best match the listening requirements.
If one equalization section does not provide sufficient equalization amplitude, a second
section can be cascaded and programmed to the same frequency to double the amplitude
in a particular frequency range. The duplicate section must be in a different bank of sections
from the first. The first bank of sections is 1 through 4, and the second bank is 5 through 7.
Once the programming has been finished, and the desired results achieved, the cover should
be replaced on the MQ108. No adjustments or changes should be made to the MQ108 pro-
gramming without using an analyzer to check the results.
NARROW FILTER WIDE FILTER
23.5
Frequency (Hz) Frequency (Hz)
7.2
Frequency (Hz) Frequency (Hz)
118
1.44
HOW TO
PROGRAM
THE MQ108
9