User manual JBL CENTURY L100

[. . . ] It is solely in the interest of ensuring a perfect listening experience that we ask you to follow the setup and hookup procedures outlined in this manual. No. 2 The Limited Edition Century Gold Bookshelf Loudspeakers set a new standard for a new century. These speakers continue the longstanding tradition of precise studio monitor sound for which JBL is famous. You will enjoy the benefits of pure titanium dome high-frequency transducers, cast-frame low-frequency transducers with vented pole pieces, and JBL's proprietary Symmetrical Field Geometry (SFGTM) magnet design, as well as high-definition dividing networks incorporating the highest quality electronic components available. Low-Frequency Transducer The Century Gold features an all-new 12" (300mm) low-frequency transducer developed specifically for the Century Gold (Figure 1). Derived from JBL's legacy of highly powerful yet efficient bass drivers, this woofer delivers full low-frequency performance with clarity and speed unprecedented among 12" drivers. [. . . ] This allows the driver to move fast enough to reproduce the dynamics of the critical midrange frequencies while retaining the low distortion characteristics necessary for accurate musical reproduction. Its very high power capability and freedom from breakup make it an ideal midrange in a system that is designed to play at high levels with absolutely no signs of distress. It makes the transition from the woofer at 600Hz, providing good dispersion throughout the important vocal range. Figure 2 Century 500 Mid-Frequency Transducer Rubber/vinyl surround 0. 4" (11mm) long, 2" (50mm) diameter edgewound aluminum voice coil for high linearity and power handling Kevlar cone Vented pole piece allows driver to run cooler Neodymium magnet provides high flux density with low mass Diecast aluminum frame for high strength High-Frequency Transducer Throughout the history of high-frequency transducer design, the goal of extended frequency response has been at odds with the need for high power handling. JBL has long chosen titanium as the material for its highest quality high-frequency transducers and the Century Gold is no exception (Figure 3). Titanium possesses the essential requirements for a high-frequency transducer. The goal is to maintain a piston-like action as high in frequency as possible. If the material flexes easily, the diaphragm will break up into random vibrations. The material is virtually immune from the cumulative effects of millions of flexures over long operating periods. These factors, coupled with the higher power handling that titanium affords, allow us to produce an extremely smooth high-frequency transducer with extended frequency response that can handle all the demands of today's digital programs. No. 4 Figure 3 050 Gold High-Frequency Transducer Titanium dome Cast zinc faceplate for less resonance 1" copper voice coil provides smooth performance and high power handling Dividing Networks The job of the dividing network is to distribute the various frequencies to their respective transducers. The network is also designed to complement component location on the baffle. Slopes are chosen to match the exact response of each driver in its respective frequency range, as well as to ensure that the high-frequency transducers are adequately protected from dangerous low-frequency components. Connecting the systems in this manner ensures that they will operate in phase; that is, they will work together rather than in opposition. Connecting the speaker system out of phase will not cause damage but will adversely affect the speaker's sound. Figure 6 Connections Bare Wire Connecting Method JBL INCORPORATED 8500 BALBOA BLVD. NORTHRIDGE, CA USA HIGH FREQUENCY LOW FREQUENCY Banana/Spade Connecting Method JBL INCORPORATED 8500 BALBOA BLVD. NORTHRIDGE, CA USA HIGH FREQUENCY LOW FREQUENCY No. 8 Figure 7 Standard Connecting Method JBL INCORPORATED 8500 BALBOA BLVD. NORTHRIDGE, CA USA HIGH FREQUENCY LOW FREQUENCY Bi-Wiring The Century Gold's outer connection panel and internal dividing network are designed so that separate sets of speaker cable can be attached to the low-frequency transducer and midrange/high-frequency transducer portions of the dividing network. Bi-wiring can provide several sonic advantages and considerably more flexibility in power amplifier selection. The advantages of bi-wiring are as follows: Reduction of Intermodulation The majority of current flowing between an amplifier and speaker is devoted to bass reproduction. In fact, 60% or more of an amplifier's output is destined for the woofers. When current flows through a wire, it produces an electro-magnetic field (EMF) that expands and collapses at a rate equal to that of the music's complex frequency components. If a single speaker wire must conduct the full musical frequency, the preponderance of lowfrequency information can interact with or modulate high frequencies. The resulting intermodulation can create audible changes to the high frequencies even before they reach the loudspeakers. [. . . ] Never connect two amplifiers to the same loudspeaker without first removing the strapping bars. Operating two amplifier channels without removing the strapping bars can seriously damage your amplifiers!Do not use conventional furniture waxes and polishes, which are not designed for oiled finishes. If touch-up is necessary or the finish appears to be drying out, the surface may be re-oiled with a commercially available oil-finishing preparation. [. . . ]