PDC-2.6P HD Preamp Processor


The DEQX Calibrated™ PDC-2.6P HD Preamp/Processor is a stereo digital processor offering DEQX’s patented speaker and room correction technology. When connected to a PC running DEQX’s software, the PDC allows you to measure and correct your main speakers and subwoofers using its largely automated Wizard driven measurement, analysis, and correction software.

Our loudspeaker’s introduce between ten to one hundred times more distortion, as well as errors in the form of inaccurate frequency-response and incoherent timing, than the signal that arrives to drive them. Unlike DSP room correction systems, whose measurements must contain room acoustic effects, the PDC first measures and corrects a speaker’s native (anechoic) behavior so that timin (phase and group-delay) errors and frequency-response errors can be compensated in detail before measuring and correcting room acoustics.

The PDC can be used for correcting passive speakers, or if you have additional amplifiers available and are able to bypass your existing passive crossovers, its six analogue outputs provide up to 3-way active crossovers. Configurations supported are; passive speakers plus the option of one or two subwoofers, 2-way active speakers plus optional subwoofers, and 3-way active speakers.

Stereo digital and analogue Inputs include: SPDIF (RCA), AES/EBU (XLR), unbalanced analog (RCA), balanced analogue (XLR). Standard outputs are analogue unbalanced (RCA). Optional outputs include balanced analogue (6 x XLR) OR Digital outputs (3 x XLR, 3 x RCA). Multiple PDC-2,6 units can connected together for multi-channel configurations such as 4.2 and 5.1 to 7.7 configurations.

The Preamp features of the PDC-2.6P HD include six digitally controlled analogue volume controls that allow the DACs to operate at their maximum resolution at low listening levels. The remote control provides volume control, input selection, four different speaker and room correction profile selections, and lo, mid and hi, tone controls where the mid control provides a fully parametric EQ band. 100 tone control settings can be set, saved and recalled using the remote control (without a PC being connected).

The industry leading SHARC 32-bit floating point DSPs from Analogue devices contribute only about 0.00001% distortion and noise. This new HD version of the PDC-2.6P contains improved power supplies and analogue electronics to preserve the system’s digital processing transparency as much as possible.


  • Provides DEQX Calibrated™ speaker correction for passive speakers
  • Automatically corrects phase and group- delay over typically 3ms window
  • Provides anechoic measurement and detailed display for speaker correction
  • Provides room-measurement/display (non-anechoic) for room correction
  • Provides DEQX-HD™ speaker correction for up to 3-way active speakers
  • DEQX-HD™ active crossovers; 48dB/octave to 300dB/octave linear-phase
  • 32-bit, floating-point, 240-MFLOPS processing with dual SHARC DSPs
  • Audiophile 24-bit 96kHz ADC-DSP-DAC processing and conversion
  • Four, user-defined ‘Profiles’ allow different crossovers, room-EQ, preferences
  • Remote tone control provides full-spectrum parametric EQ with 100-presets
  • DEQX integrated software measurement, correction and user-defined options
  • Two analog inputs: Unbalanced (2 x RCA) and Balanced (2 x XLR)
  • 90V-240VAC auto-sensing main voltage input; 30VA
  • 1U high chassis; 1.75" H x 17" W x 11.5" D
  • Online and telephone support
  • Free downloadable software and firmware updates
  • Automatically corrects frequency-response typically to plus/minus 0.5dB
  • Integrate one or two subwoofers with main speakers with time-correction
  • Patented low-latency FIR processing for speaker correction allows video use
  • Auto and real-time manual Parametric EQ over measurement display
  • Individual driver correction prior to crossover when actively implemented
  • Traditional active 3-way crossovers from 6dB/octave to 48dB/octave
  • Audiophile op-amps typically 300V/uSec slew-rate with high output drive
  • Front-panel volume control and ‘Profile’ selection
  • Remote controls; Volume, Profile, Input select, and Lo, Mid, Hi tone controls
  • Analogue volume control maintains full DAC resolution at low listening levels
  • Calibration Kit provides DEQX-calibrated measurement microphone
  • Two stereo digital inputs: S/PDIF (1 x RCA) and AES/EBU (1 x XLR)
  • Microphone input has 48V phantom power for DEQX Calibrated™ mics
  • 19” rack-mount kit option available
  • Membership of DEQX Users Group (online)
  • Six analog outputs: unbalanced (6 x RCA)

Calibration kits (option)

A Calibration kit is used for setting up all DEQX units. Each includes the DEQX measurement, analysis and correction software for PC and USB cable as well as a DEQX Calibrated™ measurement microphone with cable.

A boom microphone stand (not supplied) is required for speaker and room measurements. Stands are typically available for under $100 from a local musical instrument supply shop.

For high-end speaker correction, the Reference calibration kit is recommended due to its high performance, higher bandwidth Earthworks microphone.

Standard Calibration Kit

  • DEQX Calibrated™ Behringer measurement microphone
  • Five-metre balanced microphone cable (XLR)
  • Five-metre USB cable
  • DEQX-Cal™ PC-based measurement, correction software on CD

Reference Calibration Kit

  • DEQX calibrated EARTHWORKS measurement microphone
  • Five-metre balanced microphone cable (XLR)
  • Five-metre USB cable
  • DEQX-Cal™ PC-based measurement, correction software on CD

Optional output modules

The PDC-2.6P HD can accept one optional output module.

Balanced Out 'HD' Module

Provides six electronically balanced XLR outputs. The ‘HD’ version uses CD servos to avoid the use of series capacitors, and uses late generation extremely high slew rate op-amps for an ‘open’ 3D sound with great resolution and unconstricted detail.

Balanced Out Transformer Module

Provides six transformer-balanced XLR outputs. This modules uses six Jensen output transformers that provide complete galvanic isolation from ground noise, while providing excellent transparency.

Digital Out Module

The digital output module provides three stereo AES/EBU outputs via three XLR connectors. The unit also provides three stereo S/PDIF outputs via RCA connectors.

It also provides a fourth female XLR that will accept an AES sync input that will asynchronously sync all digital outputs to the input clock reference up to 100kHz sample rate, regardless of the input or processing sample rate.