Rockford Fosgate OEQ2 HIGH Installation & Operation Manual page 26

Symptom
Engine Noise
Engine Noise
(BLT Input)
• If noise persists, see your Authorized Rockford Fosgate Dealer.
Diagnosis
Bad component in the
signal chain.
Multiple grounds in the
audio system.
RCA and BLT inputs are
utilized simultaneously.
Noise is entering the
system via a possible
ground loop.
Jumper Placement
Diagrams
DGND
A.
Chass
AGND
DGND
B.
Chass
AGND
DGND
C.
Chass
AGND
Signal Input switch not
selected for BLT input.
– 23 –
Remedy
Check connections and bypass
additional components (cross-
overs and preamps) between
the source unit and the ampli-
fier. Connect one component
at a time using muting plugs
(RCA signal shorted to shield)
at the input of each added com-
ponent to determine the cul-
prit. Repair or replace compo-
nents as necessary.
Check ground connections
and connect amplifiers, signal
processors, and other compo-
nents to a central location or
try a different grounding point
on the chassis.
Use only RCA or BLT input at
one time.
Remove the cover from the
OEQ and locate jumper J1,
2
labeled DGND and AGND,
next to the transformer (round
donut with wires). This jumper
applies ground to the chassis
of the OEQ
possible connections:
•
A. No Jumper Connection –
•
no ground applied to the
•
chassis
•
B. DGND – power supply
•
ground applied to chassis
•
C. AGND – RCA shield ap-
•
plied to chassis
•
•
Experiment with these jumper
configuration options until a
reduction in noise is observed.
Select the Signal Input Switch
for "BAL" input.
. There are three
2
TROUBLE-S
H
O
O
T
I
N
G