Pioneer DEH-P88RS Manuel D'installation page 11

Low range output
(LOW/SUBWOOFER
OUTPUT)
The pin position of the ISO connector will differ
depends on the type of vehicle. Connect 6* and 7*
when Pin 5 is an antenna control type. In another type
of vehicle, never connect 6* and 7*.
Low range speaker
Perform this connection when using the optional amplifier.
Connecting cords with RCA pin
plugs (sold separately)
System remote control
Left
+
≠
Power amp
(sold separately)
Right
+
Low range speaker
≠
10