INTRODUCTION Congratulations on choosing JBL loudspeakers. Their highly accurate, uncolored and balanced sound character will greatly increase your enjoyment of recorded films and movies. JBL speakers are built with careful attention to detail, using only the highest quality materials. They will provide many years of excellent performance. The G Center Channel Speaker is the result of concentrated efforts to combine traditional JBL performance values with elegant contemporary appearance. It is designed to give you the clear, crisp, quality sound reproduction needed to deliver accurate, intelligible vocal information required by a center channel speaker. The G Center incorporates magnetic shielding on the drivers which prevents stray magnetic fields from creating any interference or distortion of the video picture. This allows placement of the G Center directly on top of the video monitor or TV. Your G Center is very easy to set up, but as it is a critical part of your surround system, we recommend that you take a few minutes to read this Owner's Manual before you begin and follow the instructions carefully. G SERIES LOUDSPEAKERS OWNER'S MANUAL CENTER G PLACEMENT As the center channel contains the dialog and other central action sounds, the speaker should be located very close to the Monitor/TV centered with the Monitor/TV's center line. Place the G Center directly on top of the Monitor/TV with the front edge of the speaker grille flush with the edge of the Monitor/TV. You should also have your Left and Right speakers within a 2 ft. or less height range of your G Center for proper sonic performance (see Figure 1). If for some reason you cannot place your G Center on top of the Monitor/TV, you may place it just below the Monitor/TV. When used in this position, it is recommended that you support the G Center so the speaker is angled up to point towards your seated ear level listening position. (2 ft. or less) (2 ft. or less) Figure 1 In Case Color Interference Occurs The speaker is shielded to work with video applications, however some color interference may be observed on the TV screen depending on the type of your TV set. If color interference is observed, turn your TV off for 15 minutes and move the G Center back about 1" from the front edge of the TV. Turn on the TV and recheck. If this is not far enough, move back further and experiment until the interference disappears. You may have to turn the TV off for a few minutes and turn it on again to clear the screen. Preparing the hookup wire 1. First determine the distance between G Center and the AV Receiver's center channel output. Be sure to consider any obstructions, i.e. cabinets, furniture, etc. 2. Cut a length of speaker wire this length. 3. Strip off 3/8" of insulation from both ends of each conductor. 4. Twist each set of thin wires into a tightly-bunched spiral. 5. At this point you need to identify a visual difference between the two conductors of each molded pair of speaker wire. 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 both speakers are connected identically. Push down on the button below the terminal and insert the wire, or the banana plug, through the hole (see Figure 2). Center Speaker Blk Red (­) (+) CONNECTIONS To connect the G Center to the center channel output of your AV receiver or amplifier, use two-conductor insulated wire. Your JBL dealer can recommend suitable cables, or you can buy wire at most hardware or electronic stores. We recommend #16 AWG wire as a minimum size. If your speaker is more than 30 feet (10 m) from your AV receiver or amplifier, use larger diameter, lower gauge wire. Connections are made at the terminals located on the back of the G Center speaker. The terminals accept bare wire or dual banana plugs, either of which will provide easy, secure connections. AV Receiver Center (­) (+) Figure 2 The red terminal on the loudspeaker should be connected to the red or (+) center channel connection terminal on the AV receiver or amplifier, and the black to the black or (­). Connecting the loudspeaker in this manner ensures that it will be in phase; that is, work together rather than in opposition to the left and right channel speakers. Connecting 2 G SERIES LOUDSPEAKERS loudspeakers out of phase will not damage them, but will result in less bass and poor imaging. Center Channel Volume To properly adjust your center channel volume, please refer to the owner's manual that came with your AV Receiver for proper adjustment procedures. Before you attempt to adjust the volume, you need to select the proper center channel mode on your AV Receiver. Select the "Center Normal" mode. Most amps have a "test tone" or "noise sequencer" feature to help you balance the center channel with the rest of your system. Using the controls on your AV receiver/amp, adjust the center channel level (volume) control so that the sound from the center speaker is the same level at your normal listening position, as the sound from the left and right front speakers. TROUBLESHOOTING The vast majority of new speaker "malfunctions" end up being traced to connections or switch settings. Check the following tips first, before requesting service. POWER HANDLING Thanks to its high efficiency, the JBL G Center loudspeaker will produce reasonable volume levels in a room of moderate size with very little amplifier power. However, using a small amplifier to obtain the desired volume listening levels may lead to overdriving the amplifier. This will generate high distortion levels and may cause damage to your loudspeaker. For the best performance, an amplifier should be selected with an output rating that is greater than the maximum power that will be used. This margin of reserve power will ensure that the amplifier will not attempt to deliver more power than its design allows. However, the amplifier's power rating per channel must not exceed the maximum recommended amplifier power for that specific loudspeaker model. Please see the specification section for details. Following these guidelines will provide virtually distortion-free sound reproduction and long loudspeaker life. 3 No sound at all or very faint sound from the center channel speaker 1. Speaker wire has become disconnected. 2. One of the connections between sound source and AV receiver/amp is faulty or has become disconnected. 3. AV receiver/amp center channel mode not selected. Please select a mode that activates the center channel. 4. AV receiver/amp "audio direct" switch is activated. This switch should be off to activate the 5 speaker surround mode. 5. Sound source (VDP, VCR, CD, cassette deck, turntable) not turned on, not activated, not hooked up or not selected on AV receiver/amp front panel. Speaker plays at low volumes but shuts off as volume is increased OR sound turns on and off intermittently A few strands of speaker wire may be shorting out. Recheck the connections. Recheck the impedance of the amp. GENERAL CARE The grille is held in place by pins near the edges. To remove the grille, grasp it by both top and bottom edges and pull gently. To replace grille, reposition it carefully and press gently at the corners. Do not push on the center area of the grille. 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. Spots may be removed with a commercial spot remover. Do not use any G SERIES LOUDSPEAKERS cleaners or solvents on the speaker drivers themselves. personnel who purchased from authorized military outlets should return them to a similar outlet. If purchased outside the United States, contact your local distributor to make arrangements for repair service. Do not return products to the JBL factory without prior authorization. SERVICE Should your loudspeaker ever need service, return it to the JBL dealer from whom it was purchased. If for some reason this is impractical, in the United States, call 800-336-4JBL for your nearest warranty station. Military Specifications High Frequency Dome Transducer Low Frequency (High Polymer Laminate) Crossover Frequency Frequency Response (­ 6dB) Sensitivity (1 Watt /1 meter) Nominal Impedance Recommended Amplifier Power* External Dimensions (HxWxD) External Dimensions (millimeters) Weight (each) Shipping Weight G Center 14mm Titanium Laminate 3-1/2" (Two) 5.5 kHz 80 Hz to 20 kHz 87dB 8 Ohms 10 to 80 Watts 5-3/16" x 14-1/4" x 6-5/8" 132 x 362 x 168mm 7 lbs (3.2 kg) 10 lbs (4.5 kg) *The maximum recommended amplifier power rating will insure proper system headroom to allow for occasional program peaks. We do not recommend sustained operation at these power levels. JBL continually strives to improve its products. New materials, production methods and design refinements are introduced into existing models without notice as a routine expression of our design philosophy. For this reason, JBL loudspeakers may differ in some respect from their published specifications and descriptions, but will always equal or exceed the original specifications unless otherwise stated. JBL Consumer Products, Inc. 80 Crossways Park West Woodbury, NY 11797 8500 Balboa Blvd. Northridge, CA 91329 800 336 4JBL (4525) A Harman International Company Part No. 324973-001 ...