Digital Processor Reviews

DEQX PreMate D/A processor/digital equalizer Specifications

Sidebar 1: Specifications

Description: Stereo control preamplifier with DSP-based speaker/room correction and 24-bit A/D & 32-bit D/A conversion. Inputs: 2 analog at +17dBu (XLR, RCA), 5 digital (TosLink, S/PDIF RCA, S/PDIF BNC, AES/EBU XLR, USB), 1 XLR microphone with 48V phantom power. Outputs: 4 analog (L/R Main XLR & RCA, L/R Woofer XLR & RCA), 1 full-range digital (BNC), RS-232 port and USB port for computer control. DSP: Dual Analog Devices SHARC 32-bit floating point. System latency: typically 15ms with speaker correction. Crossover slopes: 6–300dB/octave. Analog input impedance: 50k ohms. Balanced output level: 4.4V RMS default, 2.0V RMS minimum, 8.8V RMS maximum. Unbalanced output level: 2.2V RMS default, 1.0V RMS minimum, 4.4V RMS maximum. THD: 0.0005%, analog– analog.
Dimensions: 17.8" (430mm) W by 3.8" (97mm) H by 12.8" (325mm) D. Weight: 14 lbs (6.35kg).
Serial number of unit reviewed: HDP-P/M-12052013-07.
Price: $4995 with USB input and calibrated Dayton measurement microphone. DEQX XS-1 USB-Audio Option costs $495. DEQX calibration by online DEQXpert service or by dealer takes one to two hours at $99/hour. Onsite installation, including DEQXpert calibration costs $399. Approximate number of dealers: 6, plus sold on-line. Warranty: 2 years, transferable if purchased from authorized dealer.
Manufacturer: DEQX Production, 4/18 Lexington Drive, Bella Vista, NSW 2153, Australia. Tel: (61) 2-9905-6277. Fax: (61) 2-9905-8066. Web: www.deqx.com.

COMPANY INFO
DEQX Production
4/18 Lexington Drive
Bella Vista, NSW 2153
Australia
(61) 2-9905-6277
www.deqx.com
ARTICLE CONTENTS

COMMENTS
JR_Audio's picture
Submitted by JR_Audio on December 25, 2014 - 11:07am

Hi Kal

Great review and description how to work on the Speaker and the Room Optimization separately with DEQX PreMate. I know it is a bit difficult to validate, but this point make a bit difference between different “room optimization” hard- / soft-ware.

Lately I have done also some measurements on different room optimization hardware (2 of the 4 based partly on your recommendations over the last years) and separation speaker from room optimization separates the men from the boys.

With the MLSSA measurement system you can chose different lengths of the adaptive time window (where the lengths changes with time (and so the resolution over frequency)) and so you can differentiate between the results of the speaker optimization from those of the room “optimization”.

Looking forward seeing you at the CES.

Juergen

Timbo in Oz's picture
Submitted by Timbo in Oz on January 14, 2015 - 3:13pm

Does it have a simple switch option for that?

corrective_unconscious's picture
Submitted by corrective_unco... on December 25, 2014 - 6:30pm

"However, the DEQX Calibration app (v.2.93), running on a Windows XP machine, indicated that 192kHz data were downsampled to 96kHz, and 176.4 down to 88.2."

"(I haven't shown the 192kHz response, as it was identical to that at 96kHz, which suggests that the DSP signal path operates at a maximum rate of 96kHz.)"

Does this mean only the signal processing part of the component downsamples, or is this indicating that the DAC downsamples also? (Or you don't really have a true bypass option, do you?)

In either case, assuming I have understood this at a basic level, I am surprised that such an expensive component would be doing this in any of its modules. The specs seem to claim the unit accepts high resolution recordings through at least some of its digital inputs. Are those claims misleading?

DEQX's picture
Submitted by DEQX on January 27, 2015 - 4:27pm

Yes - There is a simple software switch that allows each of the four outputs (2 x main speakers and 1 or 2 optional subwoofers) to be individually phase inverted and auditioned in real-time.

John Atkinson's picture
Submitted by John Atkinson on December 26, 2014 - 5:34am
Quote:
Does this mean only the signal processing part of the component downsamples, or is this indicating that the DAC downsamples also? (Or you don't really have a true bypass option, do you?)

Though the PreMate will accept 176.4 and 192kHz datastreams, it appears that it downsamples them to half those rates before the data are presented to the DSP section, then finally the DAC. So no, there is no true bypass.

Quote:
In either case, assuming I have understood this at a basic level, I am surprised that such an expensive component would be doing this in any of its modules.

Running powerful DSP at 4Fs sample rates is very consuming of resources, so this compromise is not uncommon. It is likely that the benefits of the DSP correction outweigh the potential drop in sound quality due to the downsampling.

John Atkinson
Editor, Stereophile

corrective_unconscious's picture
Submitted by corrective_unco... on December 27, 2014 - 10:11am

Good thing the high end consumer is getting more and more choices of hi rez music. And hi rez formats!

It is hilarious, benefits of DSP or not, imo.

(Thanks for the clear explanation and confirmation.)

lhissink's picture
Submitted by lhissink on December 27, 2014 - 12:47pm

Life becomes more interesting when the speaker system is a Larsen 8 that are specifically designed to work with the floor and rear wall. My system is in a temporary location but DEQX did a preliminary speaker correction limiting the correction window from 20 to 800 Hz. But I have to wait until May or June 2015 before any more comments can be made.

And great review, and agree with the documentation - it requires deep study and time to fully utilise the software.

w1000i's picture
Submitted by w1000i on January 3, 2015 - 11:25pm

If possible I hope to see a review for wyred4sound DAC-2 DSDse :)

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