JBL Century Gold manual Mid-FrequencyTransducer, High-FrequencyTransducer

Mid-Frequency Transducer

The Century Gold also features an all-new 5" (127mm) mid-frequency transducer developed specifically for the Century Gold (Figure 2). The voice coil is 2" (50mm) in diameter and wound on edge from flat aluminum ribbon wire to a depth of precisely .4" (11mm) on a thermoset composite™ form. The cone is made of Kevlar® with a composite rubber/vinyl surround. Kevlar was chosen for the cone material because it is extremely strong and rigid while relatively low in mass. 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.

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. First, titanium is extremely light yet rigid. 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. Second, titanium is virtually free from fatigue. 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.

Figure 2 Century 500 Mid-Frequency Transducer

Rubber/vinyl	0.4" (11mm) long,
	2" (50mm)
surround
	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

No.

4

Figure 3 050 Gold High-Frequency Transducer

Titanium dome
Cast zinc faceplate	1" copper
	voice coil
for less resonance	provides
	smooth
	performance
	and high
	power
	handling