JBL 508GTI manual Designing Your System

minimizing stray magnetic fields, this closed circuit magnetic assembly design concentrates the magnetic field on the voice coil where it provides superior performance. In the woofer/midrange drivers, this high concentration of magnetic power is coupled to a 2" Edge-wound Aluminum Wire Voice Coil on a High Temperature Fiberglass Former. This voice coil uses lightweight aluminum wire to maintain the agility to reproduce high frequencies while its large diameter and fiberglass former assures extremely high thermal power handling.

Treated Kevlar fiber cones are used because of their combination of low weight, high stiffness and resistance to resonances. The 408 and 508GTi Woofer/Midranges are topped off with a treated fabric inverted dome for smooth reproduction of upper midrange frequencies.

The cone motion of these high excursion designs is controlled by a Aromatic Polyamid Fiber Spider. This new material is able to control the 0.6" motion of the cone while maintaining musical

accuracy because it is 3 times stronger than conventional spider materials.

The tweeters in the 408 and 508GTi feature domes made from pure titanium. Pure titanium has long been known to have a very high stiffness to weight ratio, making it ideal for treble reproduction. However, only JBL has “tamed” titanium through a special manufacturing process. The dome of the 408 and 508GTi Tweeter is created using special nitrogen gas cooled forming machines which can create a uniformly paper-thin dome without the work- hardening or deformation which causes resonances in domes made without benefit of this process

Equally important is the 408 and 508GTi crossover design. Each crossover was meticulously optimized in JBL’s state- of-the-art acoustic laboratory to guarantee a seamless blend of the woofer/midrange and tweeter output. Unlike generic or general purpose crossovers, the design of the 408 and 508GTi Crossovers was performed with a full knowledge of the performance characteristics of each driver, allowing frequency, phase, and power

response to be completely optimized for each combination.

What does all this technology add up to? A system with ideal frequency response, excellent off axis response, and high output capability all in a small and elegant package. The result is exceptionally smooth and detailed music reproduction over the full range of frequencies and clean sound that cuts through road noise.

Designing Your System

The overall quality of any system design is a result of how well all of the components work together, not just the result of the performance of any one component. JBL GTi Series woofer/ midbass or subwoofer transducers are the ideal companion products to your 408 and 508GTi systems. Each of the GTi Competition Series products are designed to complement the others to provide the highest performance with the simplest and most predictable system design. To use the 408 and 508GTi as the woofer/midrange

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