[. . . ] The product should be mounted on a wall or ceiling only when, and as, recommended by the manufacturer. Slots and openings in the cabinet are provided for ventilation and to ensure reliable operation of the product and to protect it from overheating, and these openings must not be blocked or covered. The openings should never be blocked by placing the product on a bed, sofa, rug or other similar surface. [. . . ] Unauthorized substitutions may result in fire, electric shock or other hazards. Upon completion of any service or repairs to this product, ask the service technician to perform safety checks to determine that the product is in proper operating condition. Do not attempt to service this product yourself, as opening or removing covers may expose you to dangerous voltage or other hazards. All the safety and operating instructions should be read before the product is operated. The safety and operating instructions should be retained for future reference. All warnings on the product and in the operating instructions should be adhered to. The product should not be used near water ­ for example, near a bathtub, washbowl, kitchen sink, laundry tub, in a wet basement or near a swimming pool, and the like. ­2­ Placement · As a general rule, bass response increases as a subwoofer is placed closer to a wall. Therefore, bass output is maximized when the subwoofer is placed in a corner. · It is also recommended that the subwoofer be positioned along the same wall as the front loudspeakers. Low-frequency sounds are normally omnidirectional, meaning the listener can't tell where they are generated from. However, frequencies between 75Hz ­ 150Hz can be localized, especially at higher volume levels. Positioning your subwoofer as recommended will provide the most natural soundstage and imaging from your loudspeaker system. Since every listening room is different, JBL strongly recommends experimenting with the positioning of your subwoofer to obtain the most pleasing results in your room. One technique that can help you find the ideal subwoofer location is to temporarily place the subwoofer near the main listening location. Then move around the room and determine where you hear the most pleasing bass performance. This would then be the ideal location for the subwoofer. RECEIVER/AMPLIFIER SPKR In Left Center Right Level Min 180 0 Max L C L I N E I N Phase Hookup When we designed the DPS-12 powered subwoofers, our goal was to offer the user the best possible performance combined with the most flexible and complete installation options. Please look over the following four examples to determine which description best matches your system and follow the corresponding hookup instructions. 1) If your receiver/amplifier has no subwoofer outputs or preamp outputs for the left, center and right channels. ­ + ­ + ­ + L I N E O U T Direct 120 L C R R SPKR Out L 90 150 60 120 180 C ­ + ­ + ­ + High Pass LEFT SPEAKER CENTER SPEAKER RIGHT SPEAKER R 120V 60Hz, 350W Power Off On 90 60 Off On 150 180 Low Pass ~ Video Contour + + + + + + ­3­ SPKR In Level Min 180 0 Max L C R SPKR Out L I N E I N RECEIVER/AMPLIFIER Phase L I N E O U T Direct 120 L C R RIGHT SUBWOOFER OUT LEFT RIGHT MAIN SPEAKER OUTPUT L C R ~ 120V 60Hz, 350W Power Off On 90 60 + ­ ­ + LEFT 150 180 120 High Pass SPKR In Level Min 180 0 Max 90 60 Off On 150 180 Low Pass L + ­ ­ + RIGHT LOUDSPEAKER LEFT LOUDSPEAKER Phase Video Contour C R L I N E I N L I N E O U T Direct 120 L C R + + + SPKR Out RECEIVER/PREAMPLIFIER Subwoofer Output L C R ~ 90 60 150 180 120 High Pass + + + 90 60 Off On 150 180 Low Pass 2) If your receiver/amplifier has subwoofer outputs or preamp output jacks for the left, center and right channels, or left and right only. [. . . ] If there is low bass output, check the following: · Make sure the connections to the left and right "Speaker Inputs" have the correct polarity (+ and ­). · Make sure that the subwoofer is plugged into an active electrical outlet. · If you are using a Dolby Digital/DTS receiver or processor, make sure that the subwoofer adjustments on the receiver/processor are set up correctly. [. . . ]