Diodes Incorporated supports THX Big Room demonstration with high performance audio DAC and pre-amp chip

One of a series of THX Big Room Certified products to be featured in the inaugural demonstration, the 8 channel ZXCZM800 performs as a digital crossover processor, providing frequency division and equalization functions for the bi-amplified front and center channels of the system. The chip is part of the Zetex Direct Digital Feedback Amplifier (DDFA(TM)) product line, supporting very high performance multi-channel DAC and digital amplifier designs.

Craig Bell, Product Marketing Manager at Diodes said, The principle of using bi-amplified high efficiency loudspeakers to deliver reference sound pressure levels in large rooms presents performance demands on all system components. For this reason, DDFA's high performance and user programmable DSP preamplifier functions make it an ideal technology for this exciting new audio concept from THX.

Providing the interface between conventional pre- and power amplifiers, the ZXCZM800 crossover processor digitally implements active crossover filter characteristics and driver time alignment to specifically match loudspeaker requirements. Compared to more traditional passive crossovers, the digital implementation replaces expensive non-linear components, thereby eliminating the loss, distortion and wide production tolerances they can cause. The system designer is also able to apply far more detailed equalisation than could be achieved with a passive approach.

The ZXCZM800's filters are fully user configurable and comprise 14 programmable biquads per channel, ensuring each channel is easily matched to its driver for the optimum audio result. This capability extends to the point of installation, thereby simplifying final choice of loudspeaker. The chip's independent programmable channel delay function also enables driver time alignment, compensating for relative driver placement within the speaker enclosure. In the CEDIA demonstration a 1ms delay in the woofer channels ensures optimum performance.

System performance is also enhanced by the chip's integrated DAC capability. A typical SNR of 120dB for each of the 8 single ended channels is comparable with that achieved by alternative high-end stereo dual differential devices.