JBL manual JBL EON15-GAGuide 9/17/02 12 30 PM Page, Noise or hiss heard at output

22376 JBL EON15-GA Guide 9/17/02 12:30 PM Page 16

Noise or hiss heard at output	Noisy source device	Disconnect the devices that are
		connected to your speaker one
		at a time. If the noise goes away,
		the problem is with the source or
		the connecting cable.
Hum or Buzz that increases or	Improper A/C ground or faulty	Disconnect or mute channels one
decreases when the mixer level	equipment connected to mixer	at a time to isolate the problem.
controls are moved.	input	Refer to the owner’s manual of
		the faulty equipment for
		troubleshooting help.
	Faulty cable between source	Substitute a known-good cable
	equipment and mixer	for the suspected faulty cable.
Hum or Buzz	Improper A/C grounding, ground	• “Telescope” the audio
	loops	ground by using an XLR/F to
		XLR/M adapter on one end.
		• Re-route audio cables away
		from AC power and lighting
		cables.
	Excessively long unbalanced	• Use the balanced outputs (if
	cable run	available) of your mixer or
		source equipment to drive
		your EON speakers.
		• Use a “DI” (direct injection)
		box to convert your
		unbalanced equipment output
		to a balanced output.
	Improper system gain structure	Reduce the INPUT 1, 2 and 3
		controls and increase the output
		level of your source devices.
The inputs from INPUT 2 and	MIX/LOOP SWITCH set	Set the MIX/LOOP SWITCH to
INPUT 3 aren’t coming out of	improperly	the MIX OUT position
the OUT connector		(depressed). See the CAUTION
		in the “Switches” section of this
		manual.
The speaker connected to the	MIXED/LOOP SWITCH set	Disengage the MIX OUT switch.
OUT connector goes up in	improperly	See the CAUTION in thedown in
volume when I adjust the INPUT		“Switches” section of this
1 control on the first speaker.		manual.
Speakers feed back and howl	Microphones are pointed into the	Move the speakers so they do
when the microphone volume is	speakers	not point the microphone’s
turned up		pickup pattern.
	Equalizer settings are incorrect	Locate the feedback frequency
		and reduce it using the mixer EQ
		or an external equalizer.
	Excessive gain	Reduce the gain at the mixer and
		move the microphone closer to
		the sound source.

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