Operating instructions

Manual-15
Constant Directivity Horn EQ Mod
Constant Directivity (or CD) horns need additional equaliza-
tion to help cover the same area 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.
is 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. e 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
below to determine the correct value capacitor to install in the
AC 23S to correct for this high frequency roll off.
STEP BY STEP PROCEDURE
is 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 third page of the
Schematics and on the circuit board.
3. Clean the solder pad on the underside of the board so that the
appropriate capacitor can be inserted. Install the capacitor,
and solder the leads from the underside using fresh solder.
Clip the excess leads.
4. Replace the top and bottom covers.
3 dB Down Frequency Capacitor
2.0 kHz .0068 µf
2.5 kHz .0056 µf
3.0 kHz .0047 µf
3.7 kHz .0039 µf
4.0 kHz .0036 µf
5.0 kHz .0030 µf
6.0 kHz .0024 µf
106001
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Monoing the Low Outputs
It is possible to mono the Low Frequency Outputs of the AC 23S
by an internal jumper. e unit should only be opened by
qualified service personnel.
1. Remove the power cord and the AC 23S top cover.
2. Move the MONO SUB OPTION header to the J9 position.
3. Moving the header to the SHIP Position puts the Low
Outputs back in stereo, as shipped from the factory.
4. Replace the cover.
5. Set both LOW DELAYS to “0”.
e mono output is now at Channel 1 LOW OUT.
Channel 2’s LOW OUT is unused.