From a land down under to RMAF 2015: DEQX calibration


rmaf-2015LOLs. A joke shared between DEQX’s Alan Langford and I is that despite living only thirty minutes drive from one another in Sydney, we only get to chat in person at overseas audio shows.

A full year has passed since DEQX’s compelling demo at last year’s RMAF where I last witnessed the sheer magnitude of improvement wrought by their PreMATE+’s time and frequency-domain correcting digital filter.

In the intervening twelve months I caught Langford punching darts in front of the Hotel Irvine at this year’s T.H.E Newport Beach Show. Did I also bump into Alan in Munich? If I didn’t it feels like I did.

This overseas connection points to a second joke shared between Langford and I. A joke that some Aussie audiophiles won’t find the least bit funny: Australia’s comparatively small population is why DEQX and I both tread the international show circuit.

DEQX’s Alan Langford and David Higginbottom at RMAF 2015.

It’s a numbers game. For DAR, it’s the hunt for fresh meat. A week on the ground in Denver followed by a further two spent writing up show report posts brings more to DAR readers than a full twelve months spent with my behind firmly affixed to a chair in Sydney town waiting for news to arrive via email.

For DEQX, it’s the pursuit of paying customers. Langford and his DEQX business partner David Higginbottom (who lives in Melbourne) do far brisker business in the USA than they’d ever hope to do on home turf. If you’re selling something, wouldn’t you prioritise a potential market of 300m Americans over 24m Australians?

Having recently, and by all accounts very successfully, exhibiited at the Hong Kong show, Langford points to China (1 billion people!) as another growth market for DEQX.

What’s the deal?

With supplied microphone attached, DEQX digital pre-amplifiers first measure your speaker’s profile, then your room’s, before applying a digital filter to correct both. And what better place to show off such wrong-righting hardware than the acoustic nightmare of a hotel room?

This brings us to the third LOL of our 2015 RMAF encounter. Langford and Higginbottom had setup up a pair of Bose Wave Radios with twin JL Fathom E110 subwoofers handling the low end. Without the DEQX HDP-5’s (US$6495) correction filter engaged, low frequencies emanating from the subs don’t arrive at the listener’s ear at the same time as the midrange and treble firing from the Bose boxes. Things sound a little off. But one doesn’t realise just how off until the time domain response is corrected (and then not).

Switching the HDP-5’s correction profile in – and then out – Langford demonstrated how much his company’s tech brings to the party: a more prominent midrange viewed through a more cleanly polished window. Cliche! Think of it another way: the HDP-5 nudges the camera lens into focus. You probably wouldn’t do the Bose + JL thing at home but it illustrates nicely just how deep the reach of DEQX’s corrective smarts.

For more serious audiophile cred, the Australians also had a pair of Magnepan 1.7, each powered by a Parasound JC1 monoblock. (Side note: am I the only one to think that the white Maggies, combined with the white net curtains, lent DEQX’s room a Vegas wedding chapel vibe?)

With this higher end setup, DEQX provided irrefutable evidence of just how well theHDP-5 brings greater lucidity and clarity to the midrange and offers more a precise lock on player placement.

Spinning source material mostly bereft of low frequencies, like Susanne Wong’s appropriate titled “Killing Me Softly”, it’s DEQX’s speaker correction that steps up to the plate. Only during the the bass heavier moments of Rodrigo and Gabriela do the room corrective capabilities of the HDP-5 make themselves known.

Without theHDP-5’s correction engaged, the Magnepans sounded narrower of soundstage, sloppier, muddier and more diffuse. You don’t know what you’ve got till it’s gone, yo.


I commented to Langford that the deltas heard in the DEQX room this year seemed to be of greater magnitude than those of the previous year. My fellow Sydney-sider agreed.

The message being broadcast by Messrs Langford and Higginbottom (should one choose to tune in) is that not only is your loudspeakers’ time domain response not ideal but neither is your room optimised for those very same loudspeakers; and then there’s the issue of the latter affecting the former.

Not everyone can accommodate the physical and aesthetic intrusion of room treatments, especially those listening in rooms that double up family spaces. Besides, the importance of listening to music as a social activity should not be underestimated; something easily lost on the headphone crowd for whom room colourations have zero impact.

Room acoustics are the single most neglected aspect of loudspeaker playback, especially by newcomers whose eyes are often bigger than their bellies. With loudspeakers not well matched to the host room, indigestion soon arrives: low frequencies obfuscate the all-important midrange. DEQX – they bring the antacid.

Expect to see further coverage in 2016.

Oh – and DEQX – it’s pronounced ‘Decks’.

Further information: DEQX




RMAF ’15 coverage brought to you by Aurender:


Written by John H. Darko

John lives in the NOW + HERE = NOWHERE. He derives an income from the ad revenues of DAR. John is also an occasional staff writer for Stereophile, 6moons and TONEAudio.

Twitter: DarkoAudio
Instagram: DarkoAudio
Facebook: DAR


Leave a Reply
  1. DEQX have designed the best sounding wedding chapel money can buy!

    After all, you want Pachelbel’s Canon to sound perfect for the big day 😉

  2. John

    I can vouch for your comments. I have used a DEQX HDP 5 for the last six months and it has transformed my fairly average system into something really interesting. I have also connected my TV to it and it has made me really enjoy the sound tracks on movies – something I never particularly noticed before.
    It is a bit daunting to set up but great fun when you get used to it.

  3. Another DEQX user here. Big improvement for my system. A superb option especially for folks without a dedicated listening room that can have lots of treatments.

    The DEQX HDP-4 also replaces a ton of other components in my system. It is functioning as my preamp and DAC in addition to the fabulous DSP duties. And vinyl lovers, it works great with analog inputs too!!!

  4. I have used DEQX since 2012….outdoor anechoic measurements, six channels of amplification including two subwoofers, room correction, time and phase alignment. It is closer to musical perfection than I ever expected & others who listen to the system seem equally impressed. A recent comment was…. ‘like sitting inside the best headphones I have ever heard but with the bass slam and feel of a live performance’.