JBL ES250P Service Manual

Also see for ES250P: Owner's guide Owner's guide Owner's guide Owner's guide Brochure

Contents

Power OnPlug your subwoofer’s AC cord into a wall outlet. Do not use the outlets on theback of the receiver.Initially set the Subwoofer-Level Control £ to the “min” position.Turn on your sub by pressing the Power Switch § on the rear panel.Turn on your entire audio system and start a CD or movie soundtrack ata moderate level.Auto On/StandbyWith the Power Switch § in the ON position, the Status LED on thetop will remain lit in red or green to indicate the On/Standby modeof the subwoofer.RED = STANDBY (No signal detected, Amp Off)GREEN = ON (Signal detected, Amp On)The subwoofer will automatically enter the Standby mode after approximately10 minutes when no signal is detected from your system. The subwoofer willthen power ON instantly when a signal is detected. During periods of normaluse, the Power Switch § can be left on. You may turn off the Power Switch§ for extended periods of nonoperation, e.g., when you are away on vacation.Adjust GainTurn your Subwoofer-Level Control £ up to the halfway position. If no soundemanates from the subwoofer, check the AC-line cord and input cables. Are theconnectors on the cables making proper contact? Is the AC plug connected toa “live” receptacle? Has the Power Switch § been pressed to the “On” position?Once you have confirmed that the subwoofer is active, proceed by playing aCD, record or cassette. Use a selection that has ample bass information.Set the overall volume control of the preamplifier or stereo to a comfortablelevel. Adjust the Subwoofer-Level Control £ until you obtain a pleasing blendof bass. Bass response should not overpower the room but rather be adjustedso there is a harmonious blend across the entire musical range. Many usershave a tendency to set the subwoofer volume too loud, adhering to the beliefthat a subwoofer is there to produce lots of bass. This is not entirely true.A subwoofer is there to enhance bass, extending the response of the entiresystem so the bass can be felt as well as heard. However, overall balancemust be maintained or the music will not sound natural. An experiencedlistener will set the volume of the subwoofer so its impact on bass responseis always there but never obtrusive.Phase ControlThe Phase Switch ¡ determines whether the subwoofer speaker’s pistonlikeaction moves in and out with the main speakers, 0˚, or opposite the mainspeakers, 180˚. Proper phase adjustment depends on several variables suchas room size, subwoofer placement and listener position. Adjust the phaseswitch to maximize bass output at the listening position.Crossover AdjustmentThe Crossover Adjustment Control ¢ determines the highest frequency atwhich the subwoofer reproduces sounds. If your main speakers can comfortablyreproduce some low-frequency sounds, set this control to a lower frequencysetting, between 50Hz and 100Hz. This will concentrate the subwoofer’sefforts 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 lowerbass frequencies, set the Crossover Adjustment control to a higher setting,between 120Hz and 150Hz.NOTE: This control will have no effect if the LFE/Normal Selector ™ is setto LFE. If you have a Dolby Digital or DTS processor/receiver, the Low-PassFrequency is set by the processor/receiver. Consult your owner’s manualto learn how to view or change this setting.The enclosure may be cleaned using a soft cloth to remove fingerprints or towipe off dust.The grille may be gently vacuumed. Stains may be removed with an aerosolcleaner, following its instructions. Do not use any solvents on the grille.All wiring connections should be inspected and cleaned or remade periodically.The frequency of maintenance depends on the metals involved in the connections,atmospheric conditions and other factors, but once per year is the minimum.If a problem occurs, make sure that all connections are properly made andclean. If a problem exists in one loudspeaker, reverse the connection wires tothe left and right system. If the problem remains in the same speaker, then thefault is with the loudspeaker. If the problem appears in the opposite speaker,the cause is in another component or cable. In the event that your subwooferever needs service, contact your local JBL dealer, or visit www.jbl.com fora service center near you.OPERATION6MAINTENANCE AND SERVICE7ES250P