JBL S4800 Owner's Manual

Contents

The new S4800 employs a 3-way,three-driver design, incorporatingan ultrahigh-frequency (UHF) com-pression driver and horn to repro-duce high frequencies up to 40kHz.With the UHF handling the ultrahighfrequencies, the high-frequency(HF) transducer could then beupgraded to a new design using a3-inch diaphragm for better repro-duction of lower frequencies andbetter blend with the woofer thanthe older generations’ 2-inchdiaphragm. Both compressiondrivers are mounted in a uniquecombination Bi-Radial® horn struc-ture, precision-molded from JBL’sproprietary SonoGlass™ material, anextremely dense and mechanicallyinert substance that is easilymolded into the unusual shapesrequired for superior acousticperformance.In order to re-create the extremelyhigh dynamic range provided bytoday’s audio sources, a new low-frequency transducer was used,incorporating a ferrite magnet, 3-inch edge-wound voice coil, andan Aquaplas-coated 15-inch conemade of Kevlar® composite, a mix-ture of Kevlar fiber and pulp mate-rial that provides increased rigidity.An EPDM rubber surround waschosen for both its flexibility andlong life. The Symmetrical FieldGeometry™ (SFG™) magnetic struc-ture minimizes second harmonicdistortion by providing a uniformflux field that prevents unevencone movement. The rigid cast-aluminum frame is also designedto minimize distortion, as alu-minum has no effect on the mag-netic field. Extensive computer-aided engineering and design effortmade to develop the optimized porttuning employed in the S4800 hasresulted in a significant advance inthe concept of state-of-the-art bassreproduction. This proprietary align-ment method offers the best damp-ing characteristics and providesextremely fast alignment, eliminat-ing the typical “bass-reflex” soundof a ported system.All three transducers are built usingthe most advanced materials andprecision manufacturing techniquesrefined from renowned JBL profes-sional sound systems.High power-handling capabilityresults in no limitations on the typesof source material. The S4800 hasvery high input sensitivity; even arelatively small high-end amplifiercan provide full dynamic rangewithout compression.Despite its power and sophistica-tion, the S4800 embodies both tradi-tion and technology. It reflects thedesign, engineering and manufac-turing expertise derived and refinedthrough nearly six decades ofexperience that are the exclusiveprovince of one loudspeakerbuilder – JBL.4SonoGlassBi-Radial Horn100˚ Horizontal60˚ VerticalCurvedDressPanelSpiked FeetFoot Base1" MDFConstruction1500FE15" LFDriverPortTube435AL3" HFCompressionDriver045Ti 1" UHFCompressionDriverFigure 1. Cutaway view of S4800 speaker system.CHAPTER 1 – THE S4800 LOUDSPEAKER:A TRIUMPH IN ACOUSTICS AND TECHNOLOGY