JBL S120PII specifications B L E S H O O T I N G, Phase Control

Phase Control

	subwoofer placement and	you happen to rearrange your
	listener position. Adjust the	listening room and move
	Phase switch ¡ to maximize	your speakers, you should
	bass output at the listening	experiment with the Phase
	position.	switch ¡ in both positions,
The Phase Control ¡	Remember, every system,	and leave it in the position
determines whether the	room and listener is different.	that maximizes bass
subwoofer’s piston-like action	There are no right or wrong	performance.
moves in and out in phase	settings; this switch ¡ offers
with the main speakers or	the added flexibility to adjust
opposite the main speakers.	your subwoofer for optimum
There is no correct or	performance for your specific
incorrect setting. Proper	listening conditions without
phase adjustment depends on	having to move your speakers.
several variables such as	If at some time in the future

T R	O U B L E S H O O T I N G
If you used the High Level		If there is low (or no) bass	If you used the	Line Level
(speaker) inputs • and there		output:	inputs ¶ and there is no
is no sound from any of the		• Make sure the connections	sound from the subwoofer:
speakers:
		to the left and right “Speaker	• Check that receiver/amplifier
• Check that receiver/amplifier		Inputs” • have the correct	is on and a source is playing.
is on and a source is playing.		polarity (+ and –).	• Check that powered
• Check that powered		• Make sure that the	subwoofer is plugged into an
subwoofer is plugged into		subwoofer is plugged into an	active electrical outlet and
an active electrical outlet		active electrical outlet and	that both Power switches
and is switched on £‚.		that both power switches	are on £‚.
• Check all wires and		are on £‚.	• Check all wires and con-
connections between		• Adjust the Crossover point	nections between receiver/
receiver/amplifier and		¢.	amplifier and subwoofer.
speakers. Make sure all wires		• Flip the Phase Control	Make sure all wires are
are connected. Make sure		switch ¡ to the opposite	connected. Make sure none
none of the speaker wires		position.	of the wires are frayed, cut
are frayed, cut or punctured.		• If you are using a Dolby	or punctured.
Make sure no wires are		Digital/DTS receiver or	• Review proper operation of
touching other wires or		processor, make sure that the	your receiver/amplifier.
terminals and creating a		subwoofer adjustments on	• Slowly turn the Level
short circuit.		the receiver/processor are	Control ∞ clockwise until
• Review proper operation		set up correctly. When using	you begin to hear the desired
of your receiver/amplifier.		the S120PII’s Speaker Level	amount of bass.
		inputs •, you should set your	• Make sure that you have
		receiver to configure the	configured your receiver/
		main left and right speakers	processor so that the
		as “LARGE”.	subwoofer/LFE output is on.
		• Slowly turn the Level
		Control ∞ clockwise until
		you begin to hear the desired
		amount of bass.

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