JBL L8400P specifications Operation, Troubleshooting, If there is low or no bass output

OPERATION

Power

Move the Master Power switch

If you will be away from home

used, switch the Master

Phase Control

¢to the “On” position to use the L8400P subwoofer.

for an extended period of time, or if the subwoofer will not be

Power switch ¢ to the “Off” position.

The Phase Control § deter- mines whether the sub- woofer’s pistonlike action

Phase switch to maximize bass output at the listening position.

having to move your speakers. If at some time in the future you happen to rearrange your

Level Control

The subwoofer Level Control

•adjusts the volume of the subwoofer relative to the rest of the system. Proper level

adjustment depends on sev- eral variables such as room size, subwoofer placement, type of main speakers and

position. Adjust the subwoofer level so that the volume of the bass information is pleasing to you.

moves in and out in phase with the main speakers or opposite the main speakers. There is no correct or incor- rect setting. Proper phase adjustment depends on sev- eral variables such as sub- woofer placement and lis- tener position. Adjust the

Remember, every system, room and listener is different. There are no right or wrong settings; this switch offers the added flexibility to adjust your subwoofer for optimum per- formance for your specific listening conditions without

listening room and move your speakers, you should experi- ment with the Phase switch in both positions, and leave it in the position that maximizes bass performance.

TROUBLESHOOTING

Crossover Adjustments

The Crossover Frequency Control ¶ determines the highest frequency at which the subwoofer reproduces sounds. If your main speakers can comfortably reproduce some low-frequency sounds, set this control to a lower frequency setting, between 50Hz and 100Hz. This will concentrate the subwoofer’s efforts on the ultradeep bass sounds required by today’s films and music. If you are using smaller bookshelf speakers that do not extend to the lower bass fre- quencies, set the low-pass crossover control to a higher setting, between 120Hz and 150Hz. This control is not used when the LFE switch ∞ is in the “LFE” position.

If you used the high-level (speaker) inputs and there is no sound from any of the speakers:

•Check that the receiver/ amplifier is on and a source is playing.

•Check that the powered subwoofer is plugged into an active electrical outlet and is switched on.

•Check all wires and connec- tions between the receiver/ amplifier and the speakers. Make sure all wires are con- nected. Make sure none of the speaker wires are frayed, cut or punctured, or touching each other.

•Review proper operation

of your receiver/amplifier.

If there is low (or no) bass output:

•Make sure the connections to the left and right “Speaker Inputs” have the correct polarity (+ and –).

•Make sure that the sub- woofer is plugged into an active electrical outlet and switched on.

•Adjust the crossover point.

•Flip the Phase Control switch to the opposite position.

•If you are using a Dolby Digital/DTS receiver or processor, make sure that the subwoofer and bass manage- ment adjustments on the receiver/processor are set up correctly.

•Slowly turn the Level Control clockwise until you begin to hear the desired amount of bass.

If you used the line-level inputs and there is no sound from the subwoofer:

•Check that the receiver/ amplifier is on and a source is playing.

•Check that the powered subwoofer is plugged into an active electrical outlet and is switched on.

•Check all wires and connections between the receiver/amplifier and the subwoofer. Make sure all wires are connected. Make sure none of the wires are frayed, cut or punctured, or touching each other.

•Review proper operation of your receiver/amplifier.

•Slowly turn the Level Control clockwise until you begin to hear the desired amount of bass.

•Make sure that you have configured your receiver/ processor so that the sub- woofer/LFE output is on.

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