Is DEQX a game changer?

11-12-14: Kr4
Got mine in the mail today!

some insider benefits, Kal! ;-) some of will have to wait until the near end of Nov before we see the Dec issue....

Got mine in the mail today!

Bruce,
good to read that you continue to like your purchase of DEQX & that you've come over to the side of time-aligned speakers. :-) Glad you recognize & hear what time-alignment can do for music playback - I feel that all my posts weren't all in vain...... at least one person listened & benefited. :-)
I'll be sure to read Kal's review of the DEQX in the Dec issue of S'phile. Thanks for this heads-up.

Drewan77 ... well our A'gon audiophile pals won't have to believe us for much longer. Kal Rubinson's DEQX PreMATE review will be published next month in the December Stereophile issue. I am not concerned that we will have to eat our hats.

If my surmise is correct, the OP's question, "Is DEQX a game changer?" will be answered shortly, and the answer may be "Yes."

I agree Bif, I thought my old Shahinian Obelisks were pretty good until I heard what DEQX did to them . I literally swore out loud in amazement the first time I played them afterwards

Drewan ... IME, as I stated above and/or elsewhere, room EQ what effects cannot be understated ... unless your sound room is an anechoic chamber. I was *VERY* surprised at how my sound room/man cave twisted the mid and bass frequencies in my right front facing speaker. The result was smeared imaging. Didn't appreciate the impact of the room issues until the DEQX effected room EQ.

Time alignment, I think goes more to tonal attributes because the impact of high order x-overs is to skew/jumble the speaker's output signal. See Roy Johnson's White Paper. Having said that, ... perhaps correcting time alignment might have other qualitative sonic benefits too.

Let's face it. Most of the tippy-top big dollar brands on the market are not time coherent, yet people still rave anyway. For example, Magico, Wilson, B&W, Daedalus, and so forth. Maybe if one gets used to sonic swill, it sounds good after a while. LOL :)

One of the reasons I jumped in with DEQX was because every review I could find was 'enthusiastic' (rather an understatement, read John Atkinsons previous comment here: http://www.stereophile.com/content/gob-smacked-deqx). Then I heard what it did for myself and I knew it was what I needed - initially just to sort out the bass my room. The speaker correction part was a bonus

John Atkinson just e mailed me and advised that Kal Rubinson is reviewing the DEQX PreMATE in the December issue of Stereophile. JA said that Kal's review is "enthusiastic." Looking forward to reading the review.

Thanks, Kal! I'm looking forward to reading it.

Best regards,
-- Al

Hey Kal. Thanks.

Upcoming Stereophile review in press now.

Ptss ... forgive my cynicism, but DEQX might get more attention if it advertised in the so-called high-end audiophile hard copy mags or web sites.

Ptss ... ditto. I'll check my e mails, but I think I asked John Atkinson and Marc Mickelson to review the DEQX. No answer yet.

I would like to see a STEREOPHILE review comparing measurements of say a Revel Salon 2 (multiple crossovers but not time aligned) versus the current best 'time aligned" speakers, both before and after DEQX. Along with comments on the sound of course.

Unsound ... on paper, I think that's true. But I wonder out loud just how time coherent so called time coherent speakers really are. That's just a question.

Presumably, if one was to use the DEQX on a 1st order time coherent speaker, there would be no need for further time alignment. That's the theory anyway.

^One could always get a dedicated room correction only system and add it to properly designed from the ground up 1st order cross-over time aligned speakers.

Drewan ... it's unfortunate that there hasn't been more buzz about the DEQX. I still believe that my rig sounds better with it. But not sure if using my CDP's on board DAC is better than the DEQX's DAC. A little different sounding for sure ... just not sure if the DEQX DAC is better. Both are very good.

Btw, I think the DEQX brings a very important plus to the table that even the best first order x-over speakers cannot do. Namely room EQ. I can't overstate the important of room EQ. A crappy room can make the best speaker system sound like crap. In my case, the FR of my speakers was so out of wack that the imaging was smeared all over the place. The DEQX significantly improved imaging.

Hopefully, more folks will road test the DEQX and post their comments.

Bruce

P.S. - I caught your last post about time aligning my speakers outside. Simply not feasible. I'd have to schlepp hundreds of pounds of gear upstairs.

Alan Langford from DEQX Australia has viewed this forum topic and emailed me as below:

"....Andrew, Just noticed your last few posts, it would be good to point out that your HDP3 used DACs from Analog Devices AD1853. The New HDP-4 & PreMate use a DAC by Burr Brown PCM-1795 and completely new I/V and analog output stages that has completely changed the sound when compared to the HDP-3. All the latest models are complete redesigns other than the DSP and some logic...."

I will only find out when I eventually change to an HDP4, it is quite possible that I may prefer this DAC over the HDP3

Drewan77, so you are taking the 'raw' digital data and converting it to analog, then feeding it to the DEQX, which then converts it back to digital for processing, etc.

I do the same for CD/SACD. My CD/SACD player has digital out, but the analog out seems to sound better to my ear. However for computer audio I prefer running the digital computer signal directly to the DEQX, rather than introduce additional digital-to-analog and analog-to-digital conversions.

Psag: "Drewan77 if you are using the HDP3, then you are utilizing its DAC. The device operates in the digital domain. The last step is digital to analogue conversion."

Partly true...I will explain:

The internal DAC for processing incoming CD or streamed data is not used as the processing is handled by an external DAC & these sources enter the DEQX as analogue signals (via balanced input)

You are of course correct that once inside the HDP3, digital conversion takes place but this is to process the crossovers, speaker calibration, phase, timing etc which is entirely different to the internal DAC handling the initial music processing. That is a separate standalone component of DEQX which I am not using

Drewan77 if you are using the HDP3, then you are utilizing its DAC. The device operates in the digital domain. The last step is digital to analogue conversion.

I tried the a/b without DEQX/with DEQX online demo at the deqx site with a pair of decent headphones. Glad to say most of what I hear at home off my OHMs with CLS (Coherent Line Source) Walsh style drivers sound much more like the with DEQX samples, as I would expect. Also I can relate to how things degrade from there in some other cases I am familiar with to various degrees, though the "without" samples in the demo sounded pretty extreme.

No doubt the "with" DEQX samples are much easier to sort through than the "without" samples.

Psag: "Drewan77, I didn't realize you were using the DEQX mate, which does not have the digital inputs."

I am not using the DEQX Mate, that was a reply I gave to Ozzy as he was looking for something with only speaker correction. My DEQX is the HDP3 which has both analogue & digital inputs, including a DAC which I no longer use

Drewan77, I didn't realize you were using the DEQX mate, which does not have the digital inputs. I must have lost track of your contributions to this thread. Sorry 'bout that.

Psag, maybe you misread what I said - here was my comment from an earlier post:

"when I compared the DEQX DAC to the Chord 64 I was previously using, it was more lively sounding and I happily used this as a replacement. I like very precise transient attack, including bass that is clean & deep but starts/stops very fast. Much more realistic to true life and the DEQX DAC has that"

The Graham Slee DAC sounds more life-like than both, being fed either CD or FLAC files. It's just as dynamic as the HDP3 DAC but more realistic at the top end. You are correct about the logic of converting an analogue signal though, it must surely have a tiny impact (I tend to judge a system on what I hear though)

"So, if I have a Dac that I like and only want the speaker correction function , is there a Deqx unit that just does that?"

Yes, the DEQX Mate does that. Use this link....

http://www.deqx.com/product-deqxmate-overview.php

....and look at 'comparison' on the drop down RH side bottom to see the various features of each processor

(Apologies to Almarg as I notice I accidentally added a second L to his forum name)

Drewan77, you wrote that the Chord DAC sounds better than the DEQX DAC. These cannot be directly be compared, because they operate at different points in the chain.

If you are feeding the DEQX an analogue signal, the DEXQ must first convert it to digital before it does anything else with it. I can only conclude that your Chord DAC is adding some 'euphonic' distortion. My preference is to use the EQ presets to alter the signal to suit my personal preferences, rather than inserting an extra component into the chain.

So, if I have a Dac that I like and only want the speaker correction function , is there a Deox unit that just does that?

Thanks ALMARG for helping us stay on track. I hope your helpful attitude becomes contagious!Very reassuring.

Allmarg is correct, apologies if I confused everybody, in my country a single ended input is often called a 'phono' socket. A phono stage is something else entirely

I should also point out that the latest HDP4 processor uses an entirely different (presumably improved) DAC compared to the HDP3 that I have. I still maintain that the primary benefit of DEQX is the speaker correction facility. Anything else is a bonus

thanks for clarifying, Almarg. RCA/single-ended input might have been a less confusing word to use...

Bombaywalla, I'm pretty certain that none of the DEQX products, or at least the current ones, include phono stages. Given that, and also given the considerable level of expertise and experience that is evident in Drewan's posts, and also given that RCA connectors are sometimes referred to as "phono connectors," I would expect that the word "phono" in his statement was simply intended to distinguish the unit's RCA input from the balanced XLR input referred to in his next sentence.

Best regards,
-- Al

10-01-14: Drewan77
Answering about the Chord DAC, this was input to the DEQX via the phono analogue input so maybe this has some bearing on the slightly dull sound.

what??? Are you serious??
you input your DAC into the phono analog input of the DEQX & let DEQX RIAA equalize your DAC input?? (The assumption here is that the input is called 'phono' because of the equalization being done to the signal; otherwise, DEQX would have called simply called it an analog input).
You know that phono is RIAA equalized because the bass freq are compressed to make them fit in a reasonable amount of space on a LP?? The effect of this would have been to accentuate your bass & make all your music bass-heavy.
And, you actually made a critical listening decision based on this connection??
wow, Drewan77, I'm amazed.....

Just trying to be helpful Drewan. Happy listening.

Answering about the Chord DAC, this was input to the DEQX via the phono analogue input so maybe this has some bearing on the slightly dull sound. Having said that, my current DAC inputs via the balanced XLR analogue input and sounds fabulous, definitely smoother and more realistic than the DEQX DAC

Answering about isolation, I already use expensive chords, a dedicated electrical circuit and power conditioning so I am confident that is sorted

Answering about the Chord DAC, this was input to the DEQX via the phono analogue input so maybe this has some bearing on the slightly dull sound. Having said that, my current DAC inputs via the balanced XLR analogue input and sounds fabulous, definitely smoother and more realistic than the DEQX DAC

Answering about isolation, I already use expensive chords, a dedicated electrical circuit and power conditioning so I am confident that is sorted

Drewan, to eliminate that "slightly more artificial and brittle"
sound it the top end- I suggest experimenting with ac isolation and conditioning devices for your unit and source, and some high quality power cords. Good luck. I agree it's difficult to acknowledge our old(er) treasures have been surpassed in ways that surprise us. (I think improved power supply management is often one of the big factors.)

Drewan77, are you using the Chord in addition to the DEXQ?

09-29-14: Bifwynne
Sorry Bombaywalla, I still think some time coherent speakers look like insects or Dr. Who Dileks.

LOL, Bruce. In my post I NEVER referred to the looks of the speakers - I was trying to stay technical & to the point - but for some reason you like to bring up this topic every time you can - it seems to give you pleasure, no? ;-)

I did audition another unnamed "Brand X" 1st order speaker about 2 years ago and my reaction was surprise and disappointment. It was just plain ugly.

sorry to read this - not every speaker designer knows how to design a good 1st order time-coherent speaker. From your text, tho', it looks like you were pre-dispositioned to dislike them; their looks seemed to have over-taken your better judgement......

Hey man, at least I'm coming over to your side of the street. I bought a DEQX and effected time coherence improvements.

yup! And, I'm happy to see that esp. since you've realized what time coherence is all about & how it positively affects the music playback. It didn't take too long for you to convert once we had all that discussion in the Sloped Baffle thread! :-) You're a quick learner, I say.

And, my speakers don't look like insects.

....but they look like coffins where you can bury your previous time-INcoherent music playback.... ;-)

Sorry Bombaywalla, I still think some time coherent speakers look like insects or Dr. Who Dileks.

I did audition another unnamed "Brand X" 1st order speaker about 2 years ago and my reaction was surprise and disappointment. It was just plain ugly.

Hey man, at least I'm coming over to your side of the street. I bought a DEQX and effected time coherence improvements. And, my speakers don't look like insects.

LOL

Bif, when I compared the DEQX DAC to the Chord 64 I was previously using, it was more lively sounding and I happily used this as a replacement. I like very precise transient attack, including bass that is clean & deep but starts/stops very fast. Much more realistic to true life and the DEQX DAC has that

The DAC I changed to at the beginning of 2014 was auditioned first and sounded just as lively but somehow has almost the same analogue 'smoothness' as vinyl (input via the HDP3 balanced XLR input). It gives me exactly what I was looking for

I did a back-to-back comparison yesterday to check again before posting and the DEQX DAC still sounds slightly more artificial and brittle at the extreme top end, a bit more 'Hi-Fi' than natural to my ears

And while some might quibble over whether their system is "flawed," I think a better way to see the picture is that design compromises have been made and time coherence is just one of the compromises. This is especially so when one considers that the "cost" of time coherence may involve ugly sloped speakers, some of which look like insects, and drivers that are being asked to make sound over a wider pass band. Plus, speaker placement can be finicky and I don't like listening to music with my head in a vice.

A few corrections, Bruce:
(1) time coherence/in-coherence in a speaker is NOT a design compromise - it's a design paradigm. Pretty much like Ralph of Atma-sphere deciding to manuf a voltage paradigm or power paradigm amplifier. Once the designer chooses the design paradigm then you can make design compromises (quality of components & other mechanical materials, etc).
(2) Drivers that are being asked to operate over a wider bandwidth in a 1st order x-over time-coherent speaker have been very carefully chosen such that these drivers have zero problems operating over that wider bandwidth. That is why most drivers on the market don't qualify. So, if the 1st order x-over time-coherent is correctly designed then the x-over frequencies will be such that these wider bandwidth capable drivers will have almost zero distortion.
(3) Speaker placement of 1st order x-over time-coherent speakers is NOT finicky & you do NOT need to put your head in a vice to listen to music. Speaker placement & listening placement have some special guidelines such as ensuring that your distance from the speakers is such that you give the sound from the various drivers to integrate & that you place you ear at the correct height off the floor. This is not unreasonable - you would do this for almost any other speaker. Yes, the sliding back/forth of the tweeter to get it correctly time-aligned to the listener's particular distance is a little bit of a trial & error thing but once again it's not unreasonable. The factory cannot set this tweeter position as different listeners listen at different distances & the distances can vary anywhere from 9'-15' depending on the speaker & room size. Once this setup is good/verified by the owner, you can shake you head like Stevie Wonder/Ray Charles or like Cerrot you can dance in your seat - sound from the 1st order x-over time-coherent will not vary....

You seem to be misguided on these few points &/or forgot that these points were discussed at length in the "Sloped Baffle" thread. Anyway, here they are again for your reading pleasure. :-) Hope that this clarifies & helps. Thanks.

Drewan ... re your comment about the DEQX DAC. I've been comparing the ARC CD-8 fully operational using its onboard DAC to going sans CD-8 DAC directly to the DEQX DAC. In the latter case, the CD-8 is being used just as a transport AND I am not using my ARC Ref 5 SE pre.

Very, very close. The DEQX may have it over the CD-8 (with DAC)/Ref 5 combo .... but it is very close.

Btw, when comparing the DEQX with time and EQ correction engaged or not engaged, or the DEQX DAC (as described above), I use a Radio Shack SPL meter. I find that when the DEQX is engaged, the SPL output is about 1 to 1.5 db higher. I try to compensate to ensure I am comparing apples to apples.

As I've alluded to earlier, on the one hand I worry that "after the fact corrections" might make difficult demands on drivers, etc., for which they weren't originally intended.
On the other hand, I wonder if these very same "after the fact corrections" were instead original design implementations they might be superior to the original way in which speakers were designed to achieve some of these performance parameters.
What ultimately arrives at our ears, regardless of how it got there, is really what counts.

Cerrot -- double agree with your next to last post. Fortunately, my amp can handle my speaker's wacko impedance and phase angle curves, especially since I am crossing over the sub and woofers at 120 Hz. A lot of watts are saved because a good part of the load is handled by the self powered sub. Also, my amp, an ARC Ref 150, has quite a bit of muscle in its own right.

And while some might quibble over whether their system is "flawed," I think a better way to see the picture is that design compromises have been made and time coherence is just one of the compromises. This is especially so when one considers that the "cost" of time coherence may involve ugly sloped speakers, some of which look like insects, and drivers that are being asked to make sound over a wider pass band. Plus, speaker placement can be finicky and I don't like listening to music with my head in a vice.

And my fix, the DEQX, while having its benefits has its costs, the least of which is NOT pecuniary, as well as adding another artifact to the signal path. Having said that, I think, but am not totally sure, that the added artifact factor may be minimal.

Bifwynne, just read your 2nd post and reponding. Thank you for the compliment. The speakers are hybrid electrostatics, with 10 inch aluminum drivers in a transmisssion line enclosure on the botton of the stat panel. I crossover at 172 Hz, with a 48 dB/octave slopes, Linkwitz-Riley filter. Each (both panels and both woofers) are fed by a pair of Magtehs. There was minor fusing with the bass signal to line it up with panel to get a purely seamless 3 demensional sound.

Bifwynne,

I totally agree with you. The problem is passive crossovers. This is why I went with hybrid stats and an active crossover. I do believe the way to eliminate the time allignment issue (not talking about the sloped baffle issue, which I am familiar and have been discussing for 30 years...) is an active crossover (or single driver, obviously). In any event, I do feel the DEQX is just an attempt of a solution for an already flawed system. Remember, time allignment is not the only problem. Impedence is the issue as well. Your amp sees your speakers crossover, not your speaker.

Thanks for the correction Al. A stupid waste of time on my part -- I checked WIKI and right you are.

Btw, Cerrot, I checked your system ... absolutely gorgeous room and STATs. Are the ESL elements full range or is there a conventional sub to fill in the bottom?? If the latter, at what frequency do the ESLs cross over?

In theory, adding additional processing into the signal path should have a negative effect. Maybe...but the benefits in my experience greatly outweigh any theoretical drawbacks and I only hear improvements. I certainly cannot detect any loss of transparency - in fact I have never had such a sense of real performers in a believable soundstage

Contributing to this thread has made me put a lot of thought into what it really is about DEQX that I find beneficial. So, in order of significance, this is the impact on MY system after using DEQX for two and a half years:

1. The ability to adjust almost everything on-the-fly whilst listening to music in your own room. - Irreplaceable, I could no longer own a system without this feature. Everything else was 'guesswork, trial & error'

2. Measuring & correcting non time-coherent speakers. Phase and timing is aligned at all frequencies, not just a 'theoretical' passover compromise - Huge impact

3. Time aligning subs - Huge impact, it is no longer possible to detect a crossover or any nulls or peaks, no matter what type of music is played

4. Ability to create crossovers at up to 72dB slopes and adjust crossover frequencies so amps & drivers operate in narrow & more efficient frequency bands, also the choice of different crossover types - Very big impact

5. Room correction - Reasonable impact (not so necessary when all the above are already dealt with anyway)

6. Preamp ability - Neutral... it seems to have no sonic signature I can detect. One more analogue input would be useful, that's all

7. Four presets selectable by remote control, each giving a slightly different adjustment to the lowest frequencies to compensate for thin or bass heavy albums - Not often used but very useful when necessary

8. DAC. Very, very good but slightly clinical - I can live without this

9. The ability to create and save further equalisation from the remote control (a huge number of presets) - Not used

Additionally:

- Ease of setup - logical but a lengthy process to do it properly. Automated widgets make a pretty good result quite easy and far simpler than any equivalent DSP I researched. Take the time to understand it and the results are fabulous

- Ease of use once understood - logical, practical and infinitely adjustable until 'perfect' at the listening seat

- Overall, the combination of 1-5 above makes the effect of your room an irrelevance and it no longer has any audible impact on the music you play. - therefore this equipment is irreplaceable (for me)

As I have said previously in this thread, please keep an open mind until you hear a fully corrected system. I was one of the biggest cynics out there until I decided to try it for myself

Excellent post by Bruce (Bifwynne), IMO. Like Cerrot, in general I too am biased in favor of minimizing what is in the signal path. But digital signal processing can do amazing things these days, that often are either not possible in the analog domain, or that cannot be achieved in the analog domain without significant tradeoffs. In this case, those tradeoffs begin with the fact that limiting one's choice of speakers to those that are time coherent rules out most of the speakers that are on the market. And for various reasons, electrostatics such as Cerrot uses are not for everyone.

In any event, putting its time correction feature aside, DEQX seems like a promising candidate in its price range just for its room correction, preamp, and DAC capabilities.

One minor correction to Bruce's post: An Nth order crossover rolls off at 6N db/octave, so 3rd order = 18 db/octave.

Best regards,
-- Al