User manual JBL J900MV

[. . . ] For example, if your listening position is 8 to 12 feet (2. 5m to 4m) from each speaker, the two systems should be about 8 feet (2. 5m) apart. Placing the loudspeakers in corners or against a wall will result in the strongest (not necessarily the most accurate) bass. Except for the J50, all J Series speakers have their ports in the front so you can place the rear of the speaker up against a wall. [. . . ] Differentiating marks can be a different color wire (copper or "silver"); a strand of yarn in one conductor; thin, raised ribs on one part of the outer insulation; or a printed "+" marking on one of the insulators. It does not make any difference which of the two strands of wire go to (+) and (­) on the speakers and amplifier, as long as all speakers used in your system are connected identically. Push down on the button below the terminal and insert the wire through the hole. For each channel, the red terminal on all loudspeakers should be connected to the red or (+) speaker connection terminal on the receiver or amplifier, Left Speaker Red Blk. (+) (­) and the black to black or (­) speaker connection terminal (see Fig. Connecting the loudspeakers in this manner ensures that they will be in phase; that is, work together rather than in opposition. This is very important when connecting several speakers together in a Dolby Pro-Logic AV application. Connecting the loudspeakers out of phase will not damage them, but will result in less bass and poor imaging. When connecting the J Center or other J Series speakers to a Dolby Pro-Logic AV receiver, refer to the instructions accompanying your AV component for use of the "test tone" to properly balance the sound output from each speaker. The use of the "test tone" and the controls on your AV receiver will enable you to correctly balance the level (volume) of sound coming from each speaker in your Dolby Pro-Logic application. Hooking Up Multiple Sets of Speakers If your receiver has two complete sets of speaker terminals ("A" and "B"), it's possible to hook up an additional pair of speakers for simultaneous sound in another room. However, some speakers may not be usable as a second pair if you want to play two sets at once. Before hooking up another set of speakers besides your J Series loudspeakers, check the following: 1. Your amplifier's minimum load impedance. Right Speaker Red Blk. Both of these specifications are expressed in ohms and both can be found in the owner's manuals which came with your speakers and amp/receiver. The receiver's minimum load impedance is determined by whether or not 4 J SERIES LOUDSPEAKERS power ratings are given for 4 ohms. This is because two sets of 8 ohm speakers will present a 4 ohm load to the receiver. The J speaker, when combined with an 8 ohm speaker, produces an impedance sufficiently close to 4 ohms. [. . . ] Do not attempt to pry the grille from the cabinet as this will void your warranty. The rear panels are removable to allow service personnel access to the driver components if needed. The loudspeaker cabinet may be cleaned with a slightly damp cloth. To remove dust from the grille cloth, use a vacuum with a brush attachment. [. . . ]