Rockford Fosgate 500 Symptom, Diagnosis, Remedy, Amplifier Noise, Engine Noise, using high level

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Symptom	Diagnosis	Remedy
Amplifier Noise	Voltage spike from remote	Use a different 12 volt source for
(Turn-on Pop)	turn-on lead is entering	REM lead of amplifier (i.e., battery
	through REM input terminal.	direct). If noise is eliminated, use a
		relay to isolate amplifier from noisy
		turn-on output.
Engine Noise	Noise is radiating into RCA	Check connections, run the RCA
	signal cable.	cables on a different route away
		from sources of high current.
	Bad component in the signal	Check connections, bypass addi-
	chain.	tional components (crossovers and
		equalizers) between the source unit
		and the amplifier. Connect one
		component at a time to determine
		the culprit. Repair or replace com-
		ponents as necessary.
	Noise is radiating into speaker	Disconnect existing speakers and
	cables.	connect a test speaker to the output
		terminals of the amplifier. If noise is
		gone, reroute the speaker cables
		away from sources of high voltage.
	Multiple grounds in the	Check ground connections and
	audio system.	connect amplifiers, signal proces-
		sors, and other components to a
		central location or try a different
		grounding point on the chassis.
	Ground loop between source	Check connections, disconnect
	unit and antenna.	antenna from source unit. If noise is
		gone, install an antenna ground
		loop isolator.
Engine Noise when	TOPAZ input circuitry (in Rock-	Supply reference ground to the
using high level	ford amps) or floating input	TOPAZ input circuit (or floating in-
inputs	circuitry (in non-Rockford	put circuit in non-Rockford amps).
	amps) does not have refer-	Connect shield of RCA input from
	ence to “chassis ground.” This	auxiliary amp to chassis ground of
	noise, if any, occurs at the	radio. An alternative method is to
	auxiliary amplifier whose in-	connect the RCA shield to the
	puts are fed from the pass-	amplifier's power ground terminal.
	thru output of the first amp.

• If noise persists, see your Authorized Rockford Fosgate Dealer.

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