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Use of high quality, premium input cables is recommended for the SP® 118P Sub, as these usually have better
shielding and materials and will provide greater long-term reliability. The best option is a shielded balanced cable
no longer than necessary to reach the SP® 118P Sub. It is usually a good idea to leave some slack at the input to
the SP® 118P Sub and also to tape the cables down or run them under a cable guard to avoid anyone tripping
over them or pulling the SP® 118P Sub over when a speaker is mounted on the pole.
Gain Control Adjustment
The SP® 118P Sub is equipped with Gain controls (6) on the input to facilitate use in many different applications.
With the Gain control adjusted fully clockwise, gain is at maximum and the input sensitivity is 0.42 V RMS for
full-rated output with the line level position of the Mic/Line switch (7). When driving the SP® 118P Sub from a
mixer, it may be advantageous to reduce the input sensitivity by turning the Gain control to the halfway point.
The SP® 118P Sub will now more closely match a typical power amp.
If the mixing board indicates clipping of its output signals, then all of the SP® 118P Sub's power capability is not
being utilized cleanly. Clipping the signal before it gets to the SP® 118P Sub is not optimal. Reduce the mixer
output level and turn up the Gain control/s on the SP® 118P Sub.
The amplifier in the SP® 118P Sub is equipped with DDT™ there is an indication on the rear panel LCD display
(12) that reads "DDT" whenever the DDT compression system engages.
If the sound seems heavily compressed, check this indicator; if it is blinking more than occasionally, then the
drive level from the mixer (or the Gain control on the SP® 118P Sub) needs to be reduced.
When first turning on the sound system, switch on all upstream electronics first, then the SP® 118P Sub with its
Gain control fully counterclockwise (all the way down). Begin checking levels with the mixer output level con-
trols all the way down, and bring them up slowly with the SP® 118P Sub Gain control/s set to the
desired setting (one-third way up recommended to start).
It is not good practice to turn the Gain control/s on the SP® 118P Sub all the way up and then try to control level
only from the mixer, this approach would tend to pick up excess noise. Best practice would be to run a "hot" sig-
nal from the mixer down the cable to the SP® 118P Sub, and then turn the SP® 118P Sub Gain control (6) up only
as much as necessary to reach full desired output. With this approach, it is necessary to verify the mixer output
is not clipping.
Setting the Levels Between the SP® 118P Sub and an SP® 2P Full-Range Speaker System
The ideal location for placement of the SP® 2P full-range speakers is on top of the SP® 118P Sub pole. In that
close proximity, the following settings will provide the best results in the crossover region, and for tonal balance.
In order to set the levels of the subwoofer and the satellite full-range speaker to each other, you first set the SP®
118P Sub gain control (6) to the straight up detent position. Then the SP® 2P gain knob should be set to the fol-
lowing position for the following gain relationship:
11:00 clock face position (first dot to the left): Sub is hot by approx. 8 dB, above the nominal level of the SP® 2P.
12 clock face position (straight-up): Sub is a little hot by approx. 4 dB, above the nominal level of the SP® 2P.
1:00 clock face position (first dot to the right): Flat setting, SP® 118P Sub and SP® 2P equal output levels.
This setting will provide the most natural reproduction of vocals and acoustic instruments, when the EQ Presets
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