User manual JBL S4800

[. . . ] OWNER'S GUIDE S4800 3-WAY FLOORSTANDING SPEAKER SYSTEM ® TABLE OF CONTENTS 3 4 8 8 9 10 11 11 15 16 17 PREFACE CHAPTER 1 ­ THE S4800 LOUDSPEAKER: A TRIUMPH IN ACOUSTICS AND TECHNOLOGY CHAPTER 2 ­ UNPACKING THE S4800 SYSTEM CHAPTER 3 ­ SELECTING CABLE CHAPTER 4 ­ AMPLIFIER RECOMMENDATIONS CHAPTER 5 ­ PLACEMENT AND SETUP CONSIDERATIONS CHAPTER 6 ­ S4800 SWITCH OPERATIONS CONTROLS AND CONNECTIONS CHAPTER 7 ­ CARE AND MAINTENANCE CHAPTER 8 ­ TROUBLESHOOTING AND SERVICE GUIDE S4800 SPECIFICATIONS 2 PREFACE Thank you for selecting a JBL® S4800 loudspeaker system. It represents the sum total of our research and developmental efforts in sound reproduction over the last half-century. We have labored to create a loudspeaker system with no acoustical or electrical limitations whatsoever. While the S4800 loudspeaker is itself a new development, the goal behind it goes right back to the earliest days of the original James B. [. . . ] In addition, the low-frequency alignment feature enables placing the speakers near, or even in, a corner without producing an overabundance of bass. This corner placement ability allows optimum performance even in small rooms. The S4800 system can operate fairly close to the wall. Leave enough clearance between the back of each speaker and the wall to allow for making the connections on the back of the speaker (approximately 2 inches ­ 3 inches is sufficient), and to avoid interference with the performance of the tuned port. Remember that these speakers weigh close to 143 lb (65kg) each and cannot be easily moved. FLOOR REQUIREMENTS The floor in the location selected for setting up the S4800 speakers must be capable of supporting a load of 143 lb (65kg) per speaker. Because of the coupling effect of the stainless-steel feet, a flat, hard surface such as wood or linoleum is preferable. However, the design of the loudspeaker's coupling system, along with the speaker's extreme weight, should result in excellent performance on any surface, even on carpets. To prevent indentations on wood or linoleum floors caused by the weight of the loudspeaker, always utilize the enclosed coasters. Do not set up the S4800 system directly on a ceramic tile floor; the concentrated weight might cause the tiles to crack. 10 Figure 7. Room placement of S4800 speaker system. CHAPTER 6 ­ S4800 SWITCH OPERATIONS The S4800 has an HF trim switch mounted on the network panel on the rear of the enclosure. The HF Trim Switch £ adjusts the high-frequency level over the range of approximately 1000Hz to 10kHz. The +1dB position gives the highest HF output and measures the most level. 0dB reduces the HF level by 1dB, and the ­1dB position reduces the HF level by an additional 1dB. Although the range of these control settings is rather small, each of them operate over a reasonably wide frequency range and thus have a noticeable effect on the overall tonal balance of the system. It is recommended that the system first be played with the switch in the middle position. This setting gives the most uniform measurements in a controlled environment. Of course, we are interested in producing the most pleasing sound in your environment with your choice of program material. It is, therefore, recommended that the HF Trim Switch £ be tested in its various settings on a variety of program material. Once you become familiar with their individual character, you should have no difficulty determining the setting that produces the most pleasing, natural sound in your room with your equipment. ¡ Mid-/High-Frequency Input Terminals: For bi-wire configurations, connect the speaker wires for the mid- and high-frequency ranges to these terminals. TM Shorting Straps: Leave the shorting straps in place only if you are using the passive singlewire connection option described on page 13. Otherwise, remove the straps to prevent possible damage to the speakers or your electronics. [. . . ] Make sure all wires are connected, and are not frayed, cut or punctured. No wires or strands should be touching each other or the shorting straps connected to other terminals. · Review proper operation of your receiver/amplifier. IF THERE IS NO SOUND COMING FROM ONE SPEAKER: · Check all wires and connections between the receiver/amplifier and the speakers. Make sure all wires are connected, and are not frayed, cut or punctured. [. . . ]