SYNTHESIS FOUR ® S4VC, S4HC & S4Ai FLUSH-MOUNT LOUDSPEAKERS OWNER’S AND INSTALLER’S MANUAL
CONTENTS INTRODUCTION ......................................................................................................................................................3 INCLUDED .............................................................................................................................................................4 SPEAKER PLACEMENT .............................................................................................................................................
INTRODUCTION ® Thank you for purchasing JBL Synthesis Four flush-mount home theater loudspeakers. These products represent the synthesis of everything that JBL has learned about the emotional power of audio and video in more than fifty years of preeminence in the field.
INCLUDED or One S4VC vertical channel flush-mount loudspeaker or One S4HC horizontal channel flush-mount loudspeaker Four mounting L-brackets with eight 1/4-20 x 3/4" screws One S4Ai multipole ambient flush-mount loudspeaker One grille with grille frame Eight 8-32 x 1/2" screws for speaker installation 4
SPEAKER PLACEMENT Positioning your loudspeakers properly is critical in order to achieve the sonic performance of a home theater. Please read the following section and the “Fine-Tuning Your Audio System” section for guidance in correct and optimal placement. L C LEFT AND RIGHT SPEAKERS: If you have purchased a Synthesis Four VIEWING POSITION Digital Home Theater System, then the model S4VC will serve as your front left and right main speakers.
SPEAKER PLACEMENT NOTE: It is extremely important to place the tweeter/mid-bass arrays for each of the center, left and right speakers at the same height. The EOS waveguide containing the tweeter in the center channel speaker should be no more than two feet higher or lower than those in the left and right speakers. This preserves the “localization integrity” of “sound pans,” in which the sound appears to move from left to center to right.
SPEAKER PLACEMENT L C R 7.1-CHANNEL SYSTEMS In a 7.1-channel system, two speakers are added for rear fill, in addition to the surround speakers in a 5.1-channel system. The two additional speakers are placed on the rear wall or near the rear wall in the ceiling (see Figure 6). SIDE LEFT SIDE RIGHT S4Ai MODES OF OPERATION The S4Ai multipole ambient surround speakers feature the unique capability of being configured in any of three operational modes.
SPEAKER PLACEMENT WHICH DIFFUSE MODE IS THE RIGHT ONE FOR THE JOB? DIPOLE MODE IS TYPICALLY USED WHEN: • The speaker is located relatively close to the listening position. • Multiple side or rear speakers are being used in a small listening room. • The speaker is mounted near, but not in, a corner and will be subject to negative reflections from nearby walls. • The room is highly reflective.
SPEAKER PLACEMENT In a 7.1-channel system, where two additional S4Ai speakers may be mounted in the rear wall, the positive phase arrays for all speakers should fire toward the rear corners, as shown in Figure 11. Thus, the side left speaker should be configured with its phase switch in the IN position, and the speaker on the right should be configured with its phase switch placed in the OUT position (see Figure 11). See the table on the right side.
SPEAKER PLACEMENT S4Ai DUAL-DRIVE MODE As the S4Ai has the capability of producing both side and rear fields from a single location in Bipole mode while dual-driven for cinema playback (see S4Ai Wiring Guide on page 7), some care must be taken when using the Direct-Radiating mode with the autoswitching trigger for music playback. ROTATE ARRAY CW Figure 13.
MOUNTING THE SPEAKERS surface, the speaker must be recessed in the wall no more than 1/4 inch. The grille pins fit directly into the speaker cabinet via receiver bushings with 15 ft/lb of tension per pin. Use the marked speaker-depth-indicator flanges (attached to the sides of the speaker baffle) to appropriately adjust the depth from the wall surface so that the baffle is recessed 1/4 inch. This will ensure that the grille will sit flush to the wall surface.
MOUNTING THE SPEAKERS REQUIREMENTS FOR MOUNTING OPTION 2 – RETROFIT/PREEXISTING CONSTRUCTION: Use the S4RFB bracket. Mount the S4RFB to the wall surface and secure it to studs behind the wall. Attach the speaker via mounting flanges to the appropriate recessed distance. The S4VC and S4HC require a minimum 6" wall depth. The S4Ai requires a minimum 4" wall depth (see Figures 18, 19 and 20). Figure 18. Mounting the S4VC speaker using the S4RFB kit Figure 19.
CONNECTING THE SPEAKERS TO THE REST OF YOUR SYSTEM To connect the Synthesis Four loudspeakers to the power amplifiers or receiver, use two-conductor insulated speaker wire. We recommend #14 AWG wire as a minimum size. Your JBL dealer can recommend suitable cables. Both the S4VC and S4HC utilize push-style friction binding posts that can accommodate up to #10 AWG stranded wire. Since the S4Ai can be configured in three different ways, be sure to run the correct number and type of wires.
FINE-TUNING YOUR AUDIO SYSTEM ACOUSTICAL PROBLEMS IN LISTENING ROOMS A home THX audio system, such as the Synthesis Four system, addresses many of the problems common to high-quality reproduction of music or soundtracks in a home environment. For example, the dispersion pattern of the front LCR speakers minimizes the effects of floor and ceiling reflections. Still, the single most important variable in any sound system is the listening environment.
FINE-TUNING YOUR AUDIO SYSTEM SOLUTIONS TO ROOM REFLECTIONS: DIFFUSION AND ABSORPTION Loudspeaker fl Re ec ted Pa th Re Listener fle c ted Pa th R te ec efl dP Re ath Direct Path Loudspeaker Direct Path However, since it is not possible to “toe-in” flush-mounted speakers, the next step is the strategic placement of absorptive materials on the side walls. These range from commercially available fiberglass and dense foam to heavy draperies and even large, overstuffed furniture.
FINE-TUNING YOUR AUDIO SYSTEM The best arrangement of the absorptive and nonabsorptive surfaces in the room can be seen in Figure 24. Most of the room surfaces are relatively absorptive, with the notable exception of the rear wall and the highest portions of the other walls, which should be diffusive. ROOM ABSORPTION FOR HOME THEATER SYSTEMS Surround speaker Screen speaker • “Dead” zone absorbs front-speaker reflection • “Live” zone provides surround propagation Figure 24.
FINE-TUNING YOUR AUDIO SYSTEM 6 degrees and having the ceiling rise toward the rear of the room at a comparable rate will do wonders for the room’s acoustics, if the wall design is solid and the angles are clearly intentional from the outset. RATTLES Rattles in the room are structural resonances (as opposed to standing waves, which are airborne resonances) that the system may stimulate due to its broad frequency response and wide dynamic range.
FINE-TUNING YOUR AUDIO SYSTEM BACKGROUND-NOISE SOLUTIONS Many sources of noise in a home environment can be addressed simply. Locating the home theater in the basement often removes it from many household noises as well as isolating it from other family members. Taking care to completely seal windows and doors can also make a significant difference in reducing outside noise. Heating and cooling systems are more challenging.
FINE-TUNING YOUR AUDIO SYSTEM STANDING-WAVE SOLUTIONS: ROOM RATIOS In new construction, the best way to minimize the audibility of standing waves is to plan for an even distribution of them, so that their effects do not “pile up” on top of each other. In this regard, the ratios of room dimensions are the critical factor. Rooms having equal dimensions are the worst, since the standing waves in all directions reinforce one another.
FINE-TUNING YOUR AUDIO SYSTEM Standing-wave energy tends to be concentrated in the corners of rooms, which is why placing a subwoofer in the corner tends to increase its bass output. Because of this, it is possible to break standing waves up somewhat by “breaking up” the corner. This can be accomplished by placing a column of thick, absorptive materials in the corners (covered by acoustically transparent cloth, of course). The column ought to be at least a foot on a side, and run from floor to ceiling.
TROUBLESHOOTING SYMPTOM PROBABLE CAUSE SOLUTION No sound coming from speaker • Amplifier not turned on • Turn on amplifier. • Amplifier gain is low • Make sure that there is amplifier gain for that channel. • Correct source not selected or turned on • Select proper source. • Defective patch cords to amplifier • Check/replace patch cords. • Speaker wires not connected to amplifier • Check speaker wire connection to amplifier.
TROUBLESHOOTING SYMPTOM PROBABLE CAUSE SOLUTION Bass is very weak • Subwoofers are wired out of phase • Make sure that positive terminals on the subwoofers go to the positive terminals on the amplifiers (red) and do the same for the negatives. • Subwoofers have not been placed optimally • Experiment with different locations. • Poor room acoustics • Use absorptive materials to minimize early reflections. Poor or smeared imaging • Aim speakers at listening area.
SPECIFICATIONS MODEL # S4VC S4HC S4Ai Description 3-Way 8" (200mm) vertical flush-mount speaker 3-Way dual 6-1/2" (165mm) horizontal flush-mount speaker Configurable-array flushmount surround speaker Power Handling 250W 250W 200W Single-driven or 175W-per-array dual-driven Nominal Impedance 6 Ohms 6 Ohms 6 Ohms Sensitivity (2.83V@1M) 91dB 91dB 91dB Frequency Response 65Hz – 20kHz 65Hz – 20kHz 80Hz – 20kHz Crossover Frequencies 600Hz, 3.5kHz 600Hz, 3.
Declaration of Conformity We, Harman Consumer Group International 2, route de Tours 72500 Château du Loir France JBL Consumer Products 250 Crossways Park Drive Woodbury, NY 11797 8500 Balboa Boulevard Northridge, CA 91329 818.830.8757 declare in own responsibility that the products described in this owner’s manual are in compliance with technical standards: EN 61000-6-3:2001 EN 61000-6-1:2001 www.jblsynthesis.com Luc Guillaume Part No.
