JBL K2 S5800 manual and enclosure technologies See Figure

After Project Everest was intro- duced, sound recording and play- back technology underwent a revolution of its own. With the advent of CD, extremely demanding recorded signals had become the rule rather than the exception – the average source material used by the typical audio enthusiast had become superior to the best demonstration material of even just a few years ago. In overall dynam- ics and transient response, trans- ducers were once again a potential weak link in the high-end audio reproduction chain.

Unlike the earlier Projects K2 S9500 and K2 S5500, the new K2 S5800 employs a 3-way, four-driver design, incorporating an ultrahigh- frequency (UHF) compression driver and horn to reproduce high fre- quencies up to 50kHz. With the UHF handling the high frequencies, the high-frequency (HF) transducer could then be upgraded to a new design using a 3-inch diaphragm for better reproduction of lower frequencies and better blend with

the dual woofers than the older generations’ 2-inch diaphragm. Both compression drivers are mounted in a unique combination Bi-Radial®horn structure, precision-molded from JBL’s proprietary SonoGlass™ material, an extremely dense and mechanically inert substance that is easily molded into the unusual shapes required for superior acoustic performance.

It was in this environment that JBL set out to create its fourth and fifth Project loudspeakers, K2 S9500 and K2 S5500. As with Hartsfield, the simplicity of a two-way system was considered the most promising design track. Advances in trans- ducer design and low-frequency alignment would make the con- struction of a two-way system

of unprecedented physical and acoustical scale possible. Engineers took the core components – the low- and high-frequency drivers – and optimized them by redesign- ing their magnetic structures, diaphragms and framework for greater linearity, dynamic capability and transient response.

In the years following the introduc- tion of the K2 S9500 and K2 S5500, sound reproduction technology has undergone another series of revolu- tionary changes, with the introduc- tion of DVD-Video, Dolby* Digital, DTS,® DVD-Audio, and Super Audio CD (SACD). Frequency responses to 50kHz and 3-digit dynamic range and signal-to-noise ratios have now become commonplace. In order to faithfully reproduce such robust sonic properties, the loudspeaker needed to undergo drastic improve- ments to its transducer, network

045Ti 1" UHF Compression Driver

SonoGlass

Bi-Radial Horn

90° Horizontal

50° Vertical

Curved

Dress

Panel

1200FE

12" LF

Driver

435AL

3" HF

Compression

Driver

1" MDF

Construction

1200FE

12" LF

Driver

Port

Tube

and enclosure technologies.

See Figure 1.

Spiked Feet

Foot Base

Figure 1. Cutaway view of Project K2 S5800 speaker system. 5