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DEQX HDP-4 and HDP-Express II now in stock!

by Nyal Mellor August 02, 2012

Just a quick update to let you know that the DEQX HDP-4 and DEQX HDP-Express II are now in stock!

These units are great sounding speaker correction, room correction and digital crossover processors. They essentially replace your pre-amp and DAC. You feed them an analog or digital signal (or signals if you have multiple sources), then the DEQX corrects speaker and room issues through powerful DSP algorithms. Implementing it in this way is called DEQX-Inline, and you can review this PDF to learn more.

You can also go active with the DEQX processors, whereby you feed each 'way' of your speaker a separate filtered signal. This digital crossover replaces the passive crossover in your speakers and improves sound quality since each driver is now direct coupled to a separate amplifier channel. This implementation is called DEQX-XO - see here for more.

The new units have 24/192 capable digital inputs for proper integration with modern music servers and feature internal 32 bit Burr Brown PCM1795 DACs. The whole main PCB has been completely redesigned to improve performance. The HDP-4 also comes as standard with balanced and digital outputs as well as a pass through ouput which makes using the HDP-4 for a four way speaker system much easier. You can use a HDP-4 for the tweeter, midrange and woofer and then use a cheaper DSP - such as a miniDSP - for one or multiple subwoofers.

 DEQX HDP-4 internal viewInside view of the DEQX HDP-4

DEQX HDP-4 analog outputsThe HDP-4 offers both single ended and balanced analog outputs as standardDEQX HDP-4 digital outputsThere are also digital outputs on BNCs and a pass through output, which replicates the input signalDEQX HDP-4 digital inputsWe now have double the number of digital inputs with an optical TOSLINK and SPDIF on BNC. There is also a USB audio input which will be enabled via a forthcoming optional plugin board.

Hope that gives you a quick overview of the new units...and as always, if you have any questions please contact us.

Nyal Mellor
Nyal Mellor


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Nyal Mellor, Founder, Acoustic Frontiers

  • (415) 524-8741
  • Serving USA & Canada
  • Fairfax, Northern California, USA

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