Crown Audio is celebrating its 65th birthday in 2012, and while this is a notable achievement for a technology company, a key contributor to our sustained success comes from an organizational willingness to view past successes in the rear view mirror and look for new ways to innovate and improve.
Yet there are also times when we look to an existing platform and explore new ways to improve it.
Both of these courses were integrated with the development of the new I-Tech 4x3500HD power amplifier, with the planning process for this 4-channel amplifier commenced only a few months after we shipped the first 2-channel models.
Around that same time, other tour-oriented DSP amplifiers were emerging on the market offering four output channels, so we decided to take the long view and develop an advanced DSP platform that would leapfrog into another generation of our I-Tech technology.
Design goals included greater application flexibility, improved performance and reliability with respect to competitive 4-channel products, seamless integration with current and future JBL loudspeaker systems while also still remaining open to use with all types of loudspeakers, and user-friendly system configuration and operation.
Starting Point
Early in the development process we consulted with a number of key users, and quickly discovered that many of them wanted a true 4 x 4 configuration: four discrete inputs that could be freely routed to any of the four outputs, singly or in any combination.
As a result, the 4x3500HD is the first in its class to offer a true 4 x 4 matrix and accept signals in four formats: analog and AES digital (on four and two XLR connectors respectively) plus CobraNet or VDrive via the RJ45 network connector.
VDrive is Crown terminology for a wiring scheme that carries two AES3 signals (four audio channels) over the four unused pairs on a standard Cat-5 or Cat-6 cable. VDrive was implemented in our VRack systems via the separate input module, but with the 4x3500HD, it is integrated directly into the input section.
The 4 x 4 input configuration provides exceptional flexibility across a range of applications. In touring applications, one obvious use would be as a high-power monitor amplifier.
But the 4x3500HD also has potential in high-end installed sound, which is why CobraNet inputs are included along with the option of binding post or Speakon output connectors.
Typical installed applications might include Las Vegas-style shows, where multiple discrete channels of high-power audio are required.
On the output side, the 4x3500HD is designed to deliver high power. Into 4 ohms, rated output (all channels driven 20 Hz – 20 kHz) is 2,400 watts, or 4,000 watts for 1 kHz (20 ms) burst. Bridging two adjacent channels gives 2 channels with each capable of an 8,000-watt burst into 4 ohms.
DriveCore Goes HD
The 4x3500HD is the first amplifier in the I-Tech HD Series to incorporate exclusive DriveCore technology, which is housed on a dime-sized IC chip that incorporates nearly all of the amplifier output stage, including the modulator stage, error amplifier stage and Crown’s proprietary feedback and PWM modulation circuits.
Developed in conjunction with the Harman Automotive Division and manufactured by Texas Instruments, DriveCore cuts the part count by about 350 for improved manufacturing efficiency and greater reliability.
More importantly, it provides better control of the output stage, a more responsive feedback loop, and comprehensive diagnostic features that reveal exactly how the amplifier is behaving.
