Specifications

(2) Input and Output Connectors

The input and output connectors are wired as follows:

XLR Pin # Function

Pin 1 Earth & Chassis Ground

Pin 2 Signal + DIFFERENTIAL INPUT

Pin 3 Signal - DIFFERENTIAL INPUT

Connector Case Earth & Chassis Ground

A positive signal applied to pin 2 of the XLR will result in a positive acoustic

pressure wave (excursion) appearing at the front of the drivers in the speak-

er system. Conversely, a positive signal appearing at pin 3 of the XLR will

result in a negative acoustic pressure wave (recursion) appearing at the front

of the speaker system’s drivers.

(3) Phase Reverse Switch

The APL-10, -12, and -SB are equipped with an input polarity-reversal switch

(also called a phase reverse switch), located adjacent to its XLR input con-

nector.When this switch is in the UP position (labeled Pin 2+), the descrip-

tion in Section 2 - "Input and Output Connectors" is correct. With this

switch in the DOWN position (labeled Pin 3+), the phase relationship will be

reversed.When the switch is DOWN, a positive signal applied to pin 2 of the

XLR will result in a negative acoustic pressure wave (recursion) appearing at

the front of the drivers in the speaker system. Conversely, a positive signal

appearing at pin 3 of the XLR will result in a positive acoustic pressure wave

(excursion) appearing at the front of the speaker system. More about the

appropriate use of this switch can be found in the, "Using the APL-10, -12,

and -SB" section.

Except in highly unusual circumstances, all subwoofers used in a common

sound system should have their Phase-Reverse Switches set in identical posi-

tions.

It is important to be aware of the position of the Phase Reverse Switch when

preparing to place the speaker in a difficult-to-reach location, such as when

flown. If by chance the APL-10, -12, or -SB is placed in an inaccessible loca-

tion and the Phase Reverse Switch is in the opposite position from that

which is desired, a common phase-reverse barrel-type line adapter can be

used to swap the polarity of pin 1 and pin 2, thereby achieving the same

result as changing the position of the switch.

(4) High-Pass Output

The APL-10, -12, and -SB are equipped with a 100 Hz, 24 dB/octave High-Pass

Output.This output produces a signal that is identical in gain to the input sig-