3
QM75.4
WIRING & CONNECTIONS
It is important to read this manual thoroughly before starting your installation and always plan accordingly.
Before installing, disconnect the negative (ground) wire from the vehicle’s battery to avoid damage to the
vehicle or yourself. Following all guidelines will help provide years of enjoyment with your STEG amplifier.
Power Supply Terminal
Œ
Ground (GND):
The ground terminal must be connected to a metal part of the vehicle with ground
Ÿ
plane back to the main battery ground attachment point (a.k.a. chassis ground). This wire should be as
short as possible, but no longer than 2ft (60cm), with minimum gauge of 8AWG. The ground wire
should be terminated with a ground specific or ring terminal and securely bolted to the vehicle with
star or lock washer and nut to prevent from coming loose. The chassis ground connection point
should be scuffed to the bare metal.
Remote Turn-on (REM):
A sw12V lead must be connected to the REM terminal to turn on the
Ÿ
amplifer, such as the source unit's remote output or vehicle switched ignition wire.
Ÿ
Power (+12V):
The co12V power connection must be made at the vehicle main battery,
securely connected with a ring terminal and protected with an in-line fuse within 18in (45cm) from the
positive battery terminal. The QM75.4 and QM500.1 require a 60A fuse (not included) and a minimum
power wire gauge of 8AWG. Do not install the fuse until all other system connections have been made.
Fuses:
These ATC fuses are to protect the amplifier and must be inserted for operation. When replacing
fuses, check for system wiring faults and always use the specified value for each fuse (30A).
Power/Protect LEDs (POW/PRO):
These LEDs indicate the amplifer status. Green indicates the amplifier
Ž
is on and in normal operation. Red indicates the amplifier is in protection mode, due to overheating,
under-voltage or output short circuit condition.
Speaker Output Terminal
Ÿ
Speaker Outputs:
Each (+) and (-) terminal pair per channel is for connecting the amplifier's output to
speaker(s) or subwoofer(s). Make sure to observe correct polarity and total impedance per channel. For
the QM75.4 model, the minimum nominal impedance is 2
Ω
per channel, or 4
Ω
for bridged
connections. For the QM500.1, the minimum total nominal impedance is 1
Ω
.
RCA Inputs (LINE IN):
The RCA input jacks are for left and right channel signals from the source. Use
quality interconnects to ensure stable connection and minimize the possibility for induced noise.
Speaker Level Inputs (HIGH LEVEL):
These inputs are for wired connection to a speaker level source,
‘
not to exceed 12Vrms. Make sure to observe correct polarity. For signals containing DC-offset, the
amplifier will automatically turn on without requiring a sw12V connection at the REM terminal.
Remote Level Controller (REMOTE):
This jack is available on the QM500.1 model only and is for
’
connecting the included remote level controller to the amplifier
Bridged Connection and Switch:
This single RCA jack is for connecting two QM500.1 mono amplifiers
“
together in a bridged configuration to provide double power for subwoofer(s) with a minimum total
nominal impedance of 2
Ω
. Set the switch to "MASTER" on the amplifier connected to the source, and set
the other amplifier's switch to "SLAVE" to receive the bridged signal.
Œ
Ž
Ž
Œ
<2ft
(60cm)
Remote
Turn-on
12V
Chassis
Ground
<18in
(45cm)
8AWG
(min)
12V
Remote
Turn-on
12V
Chassis
Ground
<18in
(45cm)
8AWG
(min)
12V
QM500.1
y
y
‘
‘
y
’
“
‘
<2ft
(60cm)