Rane AC 23S, User Manual

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17
Constant Directivity Horn EQ Modifications
Constant Directivity (CD) horns need additional equalization to
help cover the same area that a long-throw horn can cover.
Additional circuitry has been added to the AC 23S for additional
equalization of the High Frequency outputs for the CD horns.
This modification should only be attempted by an experienced
technician. It is important to know the 3 dB down point of the
CD driver's frequency response. The manufacturer of your driver
should be able to supply you with a frequency response curve.
Find the point where the high end
starts to roll off, and look for
the point on the chart that is 3 dB down from that point (toward
the right, as the higher frequencies roll off). Find the frequency
at the bottom of the chart of this point—an approximate is fine,
you don't have to be exact. Find the closest frequency in the table to determine the correct value capacitor to
install.
STEP BY STEP PROCEDURE
This procedure is for CD horn EQ on the High output in Stereo 3-Way mode. For a Mono 4- or 5-Way system with a
CD horn on the high output, only place C98 in Channel 2.
1.
Remove the top and bottom covers of the AC 23S.
2. Locate the positions for C72 and C98 on the circuit board.
3. Clean the solder pad on the underside of the board so the capacitor can be inserted. Solder the leads from the
underside with fresh solder. Clip the excess leads.
4. Replace the top and bottom covers.
3 dB Down
Frequency
Capacitor
2.0 kHz 0.0068 uF
2.5 kHz 0.0056 uF
3.0 kHz 0.0047 uF
3.7 kHz 0.0039 uF
4.0 kHz 0.0036 uF
5.0 kHz 0.0030 uF
6.0 kHz 0.0024 uF