AVA L O N audio-video consultants
in Bahrain since 1981 - company registered 1999




Box 2282, Bahrain


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Home Theatre


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"DEKS" (some say "Dee Queue eks" - no worries!) = Digital EQualisation and crossover

also check their website - you may see a great video of how DEQX works


latest DEQX HDP-5 processor... with touchscreen,
opening the door to planned WiFi control and streaming
new power supply

DEQX HDP-4 pre, correction & crossover, linear power supply


DEQX HDP-Express II... a single-ended-only Lite version




DEQX PreMATE+  front & rear, new power supply & touchscreen



DEQX PreMate



*** all models now accept the XS-1 USB 24/192 input board, permitting direct
hook up of DEQX into Windows or Mac music servers...

*** all models come in silver or black (except Express, only in black)


HDP all-in-1 models :
speaker correction, room correction, active 3-way stereo crossovers (Hi, Mid, Lo)
for 3-way active (or passive) speakers or 2-way+sub, parametric tone control,
3 x DAC and preamplifier (volume control performed in the 32-bit section)


touchscreen, planned future streaming & WiFi control;
digital and balanced analogue inputs & outputs;
audiophile components;
advanced SMPS


no touchscreen;
digital and balanced analogue inputs & outputs;
audiophile components;
linear power supply


HDP Express II
no touchscreen or facia controls;
digital and analogue unbalanced inputs;
analogue outputs;
commercial components



PreMATE models :
same as HDP except no crossovers, just 2 output ranges are available:
for the full-range passive speaker pair and separate subwoofers


touchscreen, planned future streaming & WiFi control;
digital and balanced analogue inputs & outputs;
audiophile components;
advanced SMPS


no touchscreen;
digital and balanced analogue inputs & outputs;
audiophile components;
advanced SMPS


DEQX's co-founder and key designer Kim Ryrie, gave me my first convincing
demonstration at CEDIA UK in far from ideal conditions: 2-way Mission speakers plus
subwoofer, in poor trade-show surroundings, were improved in a startling manner...

Distortions caused by the speaker & room can be
100x greater than the audio input
signal, whilst distortions caused by DEQX DSP are about
-140dB below listening level...!


DEQX firstly corrects for loudspeaker response separately from room acoustics.
Why? - firstly, the speaker will become a better speaker and the correction
will serve as the starting point before further correction for any chosen room.
One's brain can often compensate quite well for room acoustics, so even in a
"poor" room, one can still recognise a better loudspeaker.  So what is actually a
partial correction - i.e. just for the speaker's response - is relevant and can be
more appropriate, especially if one wants the widest listening area. 


Corrections generated by the calibration software correct - in a phase-linear
manner - for frequency-dependent time delays as well as amplitudes - only the
latter are addressed using ordinary EQ methods, which can often INTRODUCE phase
anomalies!  Phase coherence gives pinpoint imaging, "air" and stunning reality.

           above:    frequency       and        time-delay corrections (corrected signal latency ~10ms)


Using DEQX as a crossover, only the best operating section of each drive unit
is used, avoiding out-of-band resonances etc that passive crossovers can overlap.

Speaker performance can be transformed by bypassing their internal crossovers
(B&W included!).  Like its EQ and tone control, DEQX crossovers are phase-linear.


Room Correction:
typically, residential listening rooms suffer monstrous boomy resonances between
say 40 and 200Hz - to which we've almost become accustomed!  Removing these
booms can reveal amazing, musical detail within and beyond these frequencies,
as if several veils have been removed.

Reviews (click on comment boxes - notice the authors!)


DEQX raised the bar into audiophile territory with its 2008 HDP-3 version.
Even its DAC section is now very competitive within the industry and highly regarded.
Multiple DEQX can be used for Home Theatre, 4-ways, etc.

Starting in 1999, we used other room-correction products, eventually with some success.
But measuring procedures were quite fickle. DEQX is much easier (we can assist you with
on-site installation, and/or you can use remote DEQXpert online-assisted setup).  One
should still optimise room layout and use simple acoustic treatment first, where possible.

Properly adjusted, DEQX will banish any high-end worries you may have had.   
Results are night-to-day sensational - bringing fun back even to serious systems! 

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