JBL D2 Dual Driver at Heart of New VTX Line Array Series

With today's introduction of Harman's JBL Professional VTX line array series, JBL is also unveiling the D2 Dual Driver --which, the company says, makes the VTX Series' dramatic improvements in high-frequency sound and performance possible.

The D2 dual-diaphragm dual-voice-coil compression driver overcomes the limitations of conventional compression driver technology: limited high frequency extension due to mass of the diaphragm and voice coil, and distortion characteristics that arise due to dome breakup modes, the company says. Merging two compression drivers into a single, compact transducer with a single acoustical output, the D2 utilizes two voice coils, each with its own lightweight, polymer, annular diaphragm, its own magnet assembly, and its own specialized phasing plug. Instead of the large and "heavy" single voice coil metal dome diaphragm of conventional compression drivers, D2 is driven by two light but strong voice coils, two motive "forces" instead of one, acoustically connected to a single exit chamber.

"With two smaller diaphragms and voice coils working on the same acoustical load, the VTX line array series provides high efficiency and SPL, plus increased extreme high-frequency reproduction due to the smaller moving mass of each diaphragm and voice coil," said Paul Bauman, senior manager, tour sound, JBL Professional. "The D2 Dual Driver is a radical departure from traditional compression drivers and represents a monumental breakthrough in loudspeaker system design!"

The two annular polymer diaphragms have the same radiating area as a conventional single dome, and overall output and power handling are dramatically increased due to the lower moving mass and enhanced heat transfer obtained with two separate voice coils. The result is a compact compression driver with dramatically improved efficiency, power handling, smoother, extended high frequency response and significantly lower levels of nonlinear distortion.

Well-validated by objective measurements, the company says, D2's performance has also gone through exhaustive subjective listening tests, demonstrating its superior sound quality compared to traditional metallic, mono structure drivers. D2 provides an extreme output advantage over conventional systems allowing significantly higher array power density.

Compared to a conventional system, the D2 has double the number of voice coils and more than double the power handling, but with a 30 percent reduction in weight. This results in a dramatic increase in pure high frequency sound pressure levels in the same physical footprint. The power handling of the three D2 drivers used in the VTX V25 are each 200W per AES standard.