Is DEQX a game changer?

Yes I admit I am very fussy, maybe it's just the way I am. Most of my life I would buy some new gear, love the sound for a while, then start to notice some other shortcoming, upgrade, buy or adjust something else, try to convince myself it was improved and then the whole thing would start over again.

Why? Well, partly because I listen to a lot of live music, often several times a week & I am a perfectionist wanting to replicate that as closely as possible

I guess the fact that I no longer find reason to tweak anything, no longer think about the system & just enjoy the music means adding DEQX may have finally cured me!

I have just read these posts about the DEQX power supply and yes, I too had noticed the apparent 'downgrading' from the supposedly superior linear power supply in the HDP4 & HDP3 models

In support of Nyal, he also gave me some excellent advice when I was setting up my DEQX back in 2012 even though I am back in his 'mother' country and not a USA customer. He seems a true professional to me

I have a suspicion that the reason for his evasiveness is that he doesn't actually know and would rather not give a definitive response without knowing the facts. Whilst I absolutely endorse the products, most times I have emailed the manufacturer themselves a direct question I have received a (late), oblique or non-answer so maybe Nyal has the same experience? Their one major weakness appears to be 'retail' customer interaction, it may be different for the pro or OEM market

I also guess that listening differences in power supply would probably be very small in real world listening rather than worrying about specs alone. I have heard a system with the original PDC 2.6, an older Premate, the HDP3 and a different system with an HDP4 and all share the same remarkable transparency, clarity, imaging and realism

I also know from another European manufacturer that legislative bodies seem have an ever tightening influence on the types of PSUs being acceptable so possibly DEQX are reacting to this in the HDP5

Ptss, what you say is logical and I understand why this concerns you.

I guess I am fortunate that my HDP3 uses the same linear power supply as the HDP4. However the PDC 2.6 I first listened to and the Premate others here refer to both have 'inferior' power supplies, nevertheless all seem happy so I guess it's a question of personal expectations or the different things each listen for.

I recommend anyone who is concerned about this email Alan Langford and ask DEQX directly: [email protected]

He has always replied to me, sometimes after several days and not always with a first response that answers my question but he is helpful.

Congratulations on your purchase Almarg - I think it's very good to do the first run through of the measurement and calibration process in situ. I dragged the system outdoors when I first did this but realised a few days later that I should have done a few things differently so had to repeat it again. You will learn a lot during the first few weeks and it does take time to understand everything fully

I originally made a number of indoor measurements & the closest I managed to the result outdoor was by lifting the speakers onto a small table in the centre of the room so the driver set was roughly equidistant between floor and ceiling with the mic about 3' away and centred between the drivers but slightly higher towards the tweeter (which will be in line with your head during normal listening). Place the speaker at the extreme front edge of the table surface, even better if you have something the same width as your speaker to minimise reflections.

Place as much soft material as is practical on the floor between speakers and mic, ie a mattress if possible or several sun lounger cushions etc. You will not completely kill the floor reflections and there will be some from the ceiling but it does help

The measurement should show a point where reflections become apparent (very clear and distant outdoors but much less so in a room) and where the truncation can be made. For me, no matter how good an indoor measurement, the resulting calibration never managed to lose a slightly unnatural or hollow sound. Measurements outdoors, although a massive PITA, is so much more accurate if everything is done properly. Patience really pays off with DEQX - if you are inquisitive, make several attempts, take advice from Nyal and with experimentation it will be worth it in the end. You have the flagship processor so make the most of it and good luck!

Bruce previously sent me his files and Larry windowed at 24ms and 98% smoothing. My own outdoor measurements are windowed at 26ms & 0% smoothing because measuring 'anechoically', the plots are clear and have almost no reflections or impulses other than the speaker itself - it's an almost flat line until a clear and tiny reflection at 26.2ms which repeats every 3ms until fading away at 36ms

However the windowing I quote is based on reflections made by Bruces' setup and will be different for yours. To be safe, I would suggest you try to look for a clear smoothish area after the main impulse and before the first obvious reflection. However, that may be difficult with a somewhat confused indoor measurement

Bruce previously sent me his files and Larry windowed at 24ms and 98% smoothing. My own outdoor measurements are windowed at 26ms & 0% smoothing because measuring 'anechoically', the plots are clear and have almost no reflections or impulses other than the speaker itself - it's an almost flat line until a clear and tiny reflection at 26.2ms which repeats every 3ms until fading away at 36ms

However the windowing I quote is based on reflections made by Bruces' setup and will be different for yours. To be safe, I would suggest you try to look for a clear smoothish area after the main impulse and before the first obvious reflection. However, that may be difficult with a somewhat confused indoor measurement

Apologies for the delay in response here guys as I am in Europe and there is obviously a time difference

Answering the question about windowing - an indoor measurement is not as clear as one taken anechoically and those sent by Bruce are rather like that although it is not bad by any means. My own measurements are crystal clear, a strong main impulse followed by a virtually flat line with four 'tiny' fading reflections. What you are supposed to do is window just before the first apparent reflection (26ms vs 26.2ms in my case). Larry has windowed at 24ms although I see a fairly strong reflection at 19.6ms so this will be included in the calibration

Regarding room correction - I may be lucky in that my music room has solid walls and floor and I am able to keep speakers and chair well away from walls using the so called 'golden formula'. Using two subs has also helped so that I need minimal room equalisation: max - 1.5dB at just 33.4hz & 36.7hz and further very slight equalisation below 219hz - bass is very tight, dynamic and uncoloured (much less eq than Larry has used in Bruces' room which is in a range of -3.7 to +4.1dB between 116hz and 1469hz)

As for time alignment - I originally used DEQXperts from the manufacturers in Australia and also the Netherlands. They taught me a lot but I was never told to use unequal timing for main speakers which is what Larry has done (6.60ms LH main speaker, 6.68ms RH). Maybe it's something to do with Bruces' room or he is seated off centre? In any case time alignment needs to be checked by ear and I align the matched peaks of the subs to the first rise of the main speakers rather than the first impulse peak as Larry has done. I have listened to both arrangements and in my setup aligning to the rise rather than peak gives a natural and seamless bass response where I can clearly hear each instrument individually and especially the realistic 'growl' of a bass guitar from within the lowest frequencies

And for Subs - yes it is good that they take over the lower frequencies so that all amps and driver sets have a narrower band to work with (ie cleaner, clearer), in my case at 100hz with a 48dB Linkwitz-Riley crossover. Larry has used 120hz, 24dB and Butterworth so this may be related to the combination of speakers and subs that Bruce uses. I found that my subs (Miller & Kreisel plus B&W) sound slightly unnatural if I crossover above 100hz and at below this, my Open Baffles lose some attack

I must admit that I spent many months experimenting, taking advice, re calibrating and listening before I arrived at the optimum for my system so it all depends on how much time each of you can put into this. A DEQXpert (or another user like me) in a remote location can advise but only YOU know what you are listening to

With that in mind, I will mail Bruce and look at his latest measurements as suggested. It's a shame that this forum does not permit embedded illustrations as I could explain this so much better by screenshots of our two setups

Here to help if I can....

DEQX claim that their algorythm time aligns all frequencies within a given measured speaker, even if this is a 2 or 3 way, regardless of the crossover order or even physical placement of drivers on a flat or stepped baffle (measured at once - not so if a sub is then manually added for instance. That requires the manual 'best compromise' time alignment I have previously mentioned)

Therefore it is my understanding that Bruces' speakers have been time and phase aligned during measurement and calibration - within the limits of the microphone and the accuracy of the measuring environment but including the inbuilt passive crossovers

My reply relates to DEQX digital time alignment and not speakers that are physically aligned via the baffle and containing passive crossovers. Of course Bombaywalla is correct about that and the impact of the crossover order

This reply is to Bruces' questions - From your measurements I would say you are already using very good speakers as the response is better than I managed to achieve in-room with my original Shahinians. I guess you used quite a lot of sound absorbtion material

Investing in time aligned speakers is not really the issue as the DEQX algorythm has already time aligned all frequencies that the mic picked up from your exiting pair (including the reflections of course!)

I think the 'heavy hand' probably results from a combination of:

- In-room measurement reflections which are included in the subsequent calibration
- A poor room or placement
- Your inexperience with the room equalisation and reliance on either the auto-eq or Larry trying to set this, based on your comments over the 'phone

I sent you a couple of emails with screenshots & a suggestion to experiment by starting with less room equalisation based on the lower frequency peaks you can see on the software, playing music which tends to excite room bass nodes and adjusting or adding further points on-the-fly. You won't do any harm and you will also learn a lot!

The amount of equalisation Larry has used suggests either that your room is really challenging or that he was being guided by you by telephone & couldn't hear what was happening to adjust himself

I actually found that once the speakers are properly time aligned and using a second sub in a different position then the need for room eq becomes almost irrelevant (but setup and time alignment using step responses with the second sub etc becomes more complex). Believe me, my room created all sorts of issues back in 2011 before I started out with this. There really are none now.... so it can be done

Time Alignment outside - Looking at the screenshot of my speakers, you can see how the main impulse is sharp and fades away clearly and very fast to a flat line until the first tiny reflection at 26.2ms. The speakers are at the extreme front edge of a narrow platform, DEQX and amps are on another table many feet away to the side and the ground, 3' below the speakers is soft grass. I believe the tiny reflections are actually caused by the mic & stand because when I measured one of the subs at 3' and then 6", the same reflection appears much sooner on the closer measurement

Andrew

(note: when I say 3', I really mean 3.28 feet, ie 1 metre but as I am an older Brit, my generation is still a bit more American than European !)

There is a much simpler way to create a duplicate or modified file: open your original file as normal in the software then immediately click 'save as' from 'File' on the menu bar (top LH corner)

When the smaller window appears, simply change the file name and save. It will then create another identical .mzd file in all but name into the same root folder as the original

Provided this file remains open while you modify or add anything, any further mods or saves will apply to this, not the original. My 'working' .mzd file was built up by multiple saves this way and eventually I went back and deleted all the older, no longer needed versions

Bruces' question: 'Btw, you referred to 'time alignment' and 'time coherence'. What is the difference between the two terms?"

My explanation is a bit lengthy (as usual!) and I cover phase coherence as well. They are inter-related....

Simple answer...
You time align speaker drivers or driver sets to each other to 'achieve' time coherence

Now the detail...
When everything starts and stops at exactly the same millisecond, such as a woofer & a tweeter or a main speaker & a sub, they are then moving in a time-coherent fashion (and are also phase-coherent)

When the BEGINNING portion of each driver or speakers' pulse arrives at the listening chair microphone or listener ears at the same instant, these are time coherent speakers. I discovered a long time ago that on my system, using the DEQX viewer and the Step Response facility, time-aligning the START of the sub(s) pulse with the start of the main speaker pulse gives by far the most natural integration and bass response. Larry has aligned Bruces' sub peak with the first impulse peak of the main speakers and both appear to start at about the same time so it should be similarly so

None of this can be relied on purely by measurement & the DEQX viewer alone however because, if you think about it, the impulse plots of any speaker or sub contains ALL the frequencies emitted by those drivers and the plot just shows one combined response against Amplitude/Milliseconds

Sound waves travel at different wavelengths/speeds from the lowest/slowest to the highest/fastest frequencies so what you are aligning to is a subset of all. Rest assured however that DEQX DOES minutely time align all frequencies WITHIN any single speaker it measures. It's just the manual bit in adding subs or anything from a diffrent measurement that needs careful interpretation to achieve the goal of 'time coherence'

That is why I have found it is best to use the plots as a guide and then fine-tune adjust by ear until 'perfect' but based on several room measurements and step responses in the viewer. It was pretty easy for me once I got to that spot because every piece of music I throw at my system sounds crisp and clear with no hint of bass bloom or a crossover

Note: with a single full range speaker containing passive crossovers, or a 2-way, 3-way measured accurately at once (ie without requiring subs), then an appropriate DEQX processor will do everything for the user and it automatically becomes time and phase coherent. All that's left to do is basic room eq or maybe time align an unequally placed speaker pair

Phase coherence means simply that the twin peaks and valleys of a test tone (such as created by DEQX during measurement), exactly line up at your ear. When those different waves also start and stop at the same time, you then have a speaker that is both phase AND time coherent

While basic 'phase coherence' is often used when setting up subwoofers, particularly 'simple' AV home setups, a phase-coherent speaker/sub may not be time-coherent. I know that because before I purchased the HDP3, my M&K sub WAS phase coherent with the main speakers & in an ideal position but the result in the room was pretty annoying to say the least. It has never moved from that spot but since setting my system up as described, it has audibly 'disappeared'

Thanks for pointing that out Al, no problem at all!

I have always tried to keep my posts quite generalistic because we seem to have several potential or new users here and many of the principles behind DEQX can seem pretty bewildering at first, offputting even

I'm sorry, I am not experienced with materials for acoustic panels. Maybe Nyal could comment as I have seen a couple of recent posts from Acoustic Frontiers

Bruce: I think Bombaywalla and Al have answered your question very well, DEQX corrects exactly what it hears but, as you also suggested, it is still a function of crossover, driver design and build quality, plus 'voicing' of the cabinet as well

DEQX deals with distortion as long as the user is not trying to push a particular driver beyond what it is capable of or trying to over-compensate in the software. For instance, good as it is, DEQX is unlikely to provide distortion free 10hz bass from a 4" driver! When calibrating, the user must work intelligently with the measurement plots

I can report from experience with 3 very different sets of speakers that the results sound surprisingly similar in the same room. In the case of the first two, very significantly improved over the same setups used previously without DEQX and in a similar setup to the one that Bruce has. The third, my current and final configuration now uses everything an HDP processor has to offer (6 way) except the DAC

1. Shahinian Obelisks including passive inbuilt crossover driven by one amp + one M&K sub (<120hz)
2. JBL stand mounts including passive inbuilt crossover driven by one amp + two M&K subs (<110hz)
3. Open baffle floorstanders, bi amped with two amps, treble crossed at 3100khz + one M&K and one B&W sub (<100hz)

Smooth frequency response, clean, tight bass and musical clarity were very similar among all three setups. If there was a shared character, I would have to call it 'transparent and neutral'

The Shaninians, probably by nature of their multiple 360 degree radiating mid & treble drivers had the poorest imaging and a more indstinct soundstage but with huge width and depth. Still fabulous sounding though

The JBL setup imaged extremely well and had the sense of a neat but smaller 3D soundstage and encouraged me to then move on to, what I consider one of DEQX-HDPs greatest strengths - the ability to incorporate multiple amps and steep crossovers

When not listening to my home system (or with my wife!), I am normally with like minded friends listening to live music and realistic transient attack had always been my goal because that is one area I had never been able to resolve, no matter what I listened to in dealers, at shows etc - until I heard another, OB based system with a DEQX processor in it. To achieve the necessary midrange speed/cleanness I decided that I wanted to avoid any sort of cabinet colouration so started researching Open Baffle Speakers myself

I prototyped various designs for a long time before commissioning a CNC workshop to manufacture the frames for my final design: 1" thick Zebrano Bamboo floorstanders with a d'Appolito configuration of Aluminium/Magnesium midrange drivers and ribbon tweeters. Large, heavy speakers but exceptional transient speed with a real sense of musical reality...in fact unbelievably so on a lot of recordings

One other comment about DEQX correcting 'what it hears' - I do have experience of comparing music corrected from an in-room and outdoor measurement of both the Shaninians and JBLs and although in theory the software should correct to the same resulting sound, it does not. My in-room measurements always resulted in a slightly unnatural, nasal hollowness to music playback and with my desire to achieve 'perfection' it wasn't quite good enough

Hi Bruce, my OBs only handle 100hz and upwards - each using four mid range drivers plus ribbon tweeters. All these are physically aligned (to the originating point of each) within a flat, tall and wide baffle & the speakers also have shallow tapering 'sides' which blend to the top edge. Sound waves can pass across the front surface and away to the sides but are constrained so they also transmit (only) to the rear. Nothing else behind the speakers apart from cabling and a single protective capacitor for each tweeter

There is free space beside and behind the speakers and I have no obvious issue with back reflections or wave effects/cancellations - but that's not to say they aren't there, it's just not apparent and I have no reason to check. The music room also has a lot of diffusing and absorbing material including a great deal of vinyl (+ CD storage)

In everything I have done, listening and then adapting has been the mantra until I achieve the sound I want - this has always been referenced to natural sounding live music. Research, theory and specifications are extremely useful but the real question should be 'what does music actually sound like'?

Sure, I made mistakes and I produced multiple low cost OB prototypes - each time I heard something I wasn't happy with, I then researched that particular aspect and adapted until it sounded right. My original intention was to try out OBs, learn and then build a pair of Linkwitz-Rileys but my own developments started to sound so good that I saw no need to follow that path. Maybe I just hit lucky or it's probably more likely that DEQX is capable of fully correcting something that is nearly there already?

I am confident that in my room and with my (mostly analogue source) preferences, this system is about as good as I could hope for

I have done nothing more to my setup for at least 2 years and can find no fault (so far). For the previous 40 odd years I constantly replaced and upgraded.... 'chasing the wind' as it were. Not any more and that's why I am very happy to see Bruce, Al and others starting on the same path because I know that the end point can be so satisfying

Congratulations Al, an excellent summary!

You have been very thorough in measuring your speakers and I am sure Nyal will give excellent advice to get the best from the system

We all look forward to your further updates

Hi Swampwalker, I have sent you a PM with my email address

A very interesting summary Al and I sympathise with the challenges you face

At the risk of repeating myself (apologies), are you absolutely sure that there is no chance of taking an outdoor speaker measurement?

I originally made several attempts to achieve a good indoor measurement but none came close to those taken outdoors. Once I saw the cleanness of the resulting plots, any further speakers or subs were always measured this way - including manhandling a huge Miller & Kreisel sub into the garden and then up onto the measuring platform which was a great deal of effort

It does make a significant difference and I believe that is why music created from the resulting calibrations sounds so remarkable. I am rather a 'perfectionist' so I couldn’t have rested knowing that I wasn't getting the maximum performance from DEQX

Yes, this can involve a lot of time and commitment (in my case around three hours from start to finish, moving the gear etc) but provided you use a high number of averaged measurements (I recommend 1.4s/96K x at least 18 sweeps) and the day is completely dry without much wind, the measurements only need to be taken once and are extremely accurate, virtually anechoic if done well. Any random birdsong or other faint wind noises appear to be completely disregarded by the averaging feature of the software

Somewhere I may have photographs of the setup but they are not on this computer so I will have to look for them. If anyone is interested I would try to find them plus some of the resulting measurement plots and post them as images on 'my page'

I have posted a couple of screenshots under 'System' at the foot of my posts for anyone with a DEQX processor to compare the plots

The measurement shows how 'clean' the frequency plot may look relative to an indoor reading that others may have taken and the impulse response illustrates that there is only a tiny reflection from the microphone itself

(The measurement is a raw image from the mid-high range speaker before any correction & at 0% smoothing. Indoor calibrations tend to use up to 100% smoothing and a closer windowing, both of which reduce accuracy and have an impact on the sound in my experience)

I can only report my own experience and with music playing, it sounds totally believable from the outdoor measurements. Using the same settings from calibration to configuration with the best indoor readings I could achieve, music and especially mid-bass had a slight hollow-nasal quality to it and was not as natural

I am using Open baffle speakers which I appreciate are very different to those being used by Al, Bruce etc but this quality was also present in the full range Shaninians when comparisons were originally made

I feel at a loss to convey with words just how close to perfect a well set up DEQX enabled system can get. For sure there are still going to be a lot of very satisfied users provided measurements are taken to the optimum in the environment available

I'm sorry to say that I don't quite agree with that last sentiment Bombaywalla. Unless someone has heard this themselves, they may not understand how good the resulting sound can be from a good indoor measurement and the majority of people will be extremely satisfied with that

Its a bit like saying that someone buys a top-range sports car but only drives it to 60% of its speed-handling capability. Another owns the same car but takes it to track days at a local circuit. Who is to say which owner gets the most pleasure?

DEQXs' main selling point is the ability to tame the room/speaker interface and it does that better than anything else I have experienced - we are talking about degrees of perfection here and each user will have different expectations

I mentioned a slight nasal quality to mid bass and by 'slight' I really do mean that. Many people probably wouldn't even notice or worry about it. I have listened to two other European DEQX setups, both sounded amazing and the owners were very pleased. Neither sounded quite as smooth or natural as mine does....to MY ears and MY tastes, which is the point I am trying to make

Bombaywalla - Without re-reading my earliest posts, I believe I may have mentioned my reaction from the very first time I played the DEQX corrected system. I swore out loud - it was that good compared to what I was familiar with. That was from the initial (indoor) measurement

Over extended listening I noticed the slight nasal quality and after re-running the measurements outside I was able to eradicate this. I expect a first time listener may not notice that, or more likely, others may not be as critical as I am

It's not possible to answer that question Ptss, I'm afraid because there are too many variables involved, not least the impact the room has on the sound and your ability to optimise that.

However speaking personally, I am confident from the experience I have that DEQX can significantly improve any speakers/room you would be confronted with because I have already done this several times using a DEQX processor.

The JBL 250Tis are a 3-way design and if you are brave enough to do it, bypassing the internal circuitry and using 6 channels of amplification (ie HDP-4 OR HDP-5) and digital crossovers are what I would do.

Even a Premate or Express will help you get the best from these without modification but whatever you consider, the end result will only be as good as the time and effort you are prepared to invest.

I have linked here to the same measurements for my speakers (midrange-treble only) for comparison.

These were taken outdoors and you can see a similar reflection from the mic (or maybe the grass surface), starting at 26ms.

Almarg, from your measurements I would initially window just before the reflection at 14ms and calibrate from there

Bruce - I believe that Al's measurements are of full range speakers and the amp & cabling running to the speaker in the photos (+ the descriptions in the plots themselves) seem to confirm this. I don't see separate step response graphs for tweeter/mid and woofer but two graphs of the same measurement where Al has changed the scale (0-10ms on the 1st, 0-40ms on the 2nd).

Group delay is the time that it takes for the modulation signal to pass through the system/air and arrive at the microphone, measured against frequency. In simple terms, it's an indicator of how much the signal will be distorted - the DEQX introductory video on their website demonstrates this 'smearing' effect.

A word of explanation when viewing the plots I have posted and comparing with those of either Bruce or Al who use manufacturer optimised speakers:

These are Open Baffle speakers for only midrange & treble frequencies. The outdoor measurements are of the raw speakers themselves, containing only one (ribbon tweeter) capacitor per speaker, no passive crossover components and with no phase, time or group delay correction whatsoever. I have let DEQX handle all of that - which it does superbly

Yes Al your interpretations are correct. It's also worth pointing out that my graphs are the 'sum' of tweeter and midrange readings taken concurrently for each speaker so I could produce comparative graphs to your own (I am using six channels of amplification in this setup and these graphs relate to four of them).

When I look at the individual midrange or tweeter plots, the Group Delay variances are quite a lot lower than the summed result you see. I am also able to view each measurement graph per driver and that helped me during the prototyping phase of developing the speakers to arrive at both the measurement and the sound I was after.

In each measurement I took, it was gratifying to see how close the plots of each speaker became. I had specified matched pairs of drivers when I purchased them and the workshop cutting the various speaker panels programmed the CNC to very fine tolerances based on my drawings. The finished speakers measured to be virtually identical even before DEQX calibration (not to imply that they sounded good until after correction).

Good progress Al. As you mention, over the coming days when you start to evaluate by listening, I recommend you play familiar music, preferably with a fair amount going on in the bass frequencies. It's at this point that you may choose to vary the correction limits slightly and load four marginally different configs to compare how they sound side-by-side.

As you become more familiar with the software, you may repeat this several times until you arrive at exactly what you want. Nothing beats playing the most 'challenging' music in your collection and making minor corrections until you have eradicated every possible irritation. In my case, I am quite inquisitive and experimented by slightly changing the correction limit frequencies, amplitudes, crossover points, slopes etc until I learned the impact of each variable. All the time keeping close to the original recommendations of Alan Langford and the DEQXperts I consulted. The only aspect that I have never modified is the original measurement window boundary.

This took around six months or so because I am also dealing with digital crossovers and time alignment to two separate subs which in themselves needed alignment together so the setup has more complexity and variables. More than two years later I have not found any music that needs me to change anything so the effort was well worth it.

User observations about 'transparency' always seem to generate controversy on internet audio forums. People who have not listened to a DEQX corrected system often assert that absolute transparency is not possible with the amount of digital correction taking place.

However, those of us open minded enough to own and use DEQX seem to notice transparency and clarity as some of the most apparent features. Too often, audio equipment is pre-judged by specifications and not by listening.

Since I last posted on here I have added an HDP-5 processor/preamp and as Almarg mentions, this has a low noise switch mode power supply. My HDP-3 uses a linear supply and both sound equally transparent with no top end glare that I can detect. Most of my listening is analogue input from two turntables and my various power amps & subs are also connected via unbalanced RCA cabling.

The HDP-5 has slightly greater clarity and openness to the soundstage than the HDP-3 & I will be using them together in a 4-way stereo setup (0-60hz, 60-200hz, 200-3100hz, 3100khz+), the HDP-3 managing just the subs.

Hi Jeff
Although I do not use my HDP-5 & HDP-3 processors in a home theatre setup, you have the facility to use one of the four (remote control selectable) config setups as a bypass.

If the Main Filter is set to "Bypass correction or crossover for this loudspeaker, but still use filters" & then against Limit Filters, untick both low & high pass filters (a new config defaults to this anyway), the speakers will still operate but in bypass fashion.

Any further queries, I recommend you contact Alan Langford at DEQX to confirm: [email protected]

Please also note that Roon for DEQX is shown as 'coming soon' on the Roon site.

As a largely analogue listener, digital processing is undetectable in my setup. Clarity/transparency is outstanding & I suppose that the things DEQX corrects have far greater benefits than any DSP impact, even if it's there.

Let us know how you get on.....

Andrew

Output volume levels from the DEQX can be set higher or lower on any or all of the four configs so you can adjust accordingly. 

If 2 channel is your priority then in my experience nothing comes close to DEQX, especially if you are able to conduct initial measurements outdoors. 

Andrew

I am using an external DAC which processes CD and FLAC files via the balanced analogue inputs on the HDP-5. The DEQX DAC is excellent but my preference is for something which is almost indistinguishable from other analogue sources - without any sense of digital glare which is present in every other DAC I have experienced.

In my system, the HDP-5 RCA analogue input takes the main turntable & the balanced XLR analogue input has the external DAC which also has a pass through for a second turntable & an SACD player. I do not use any of the digital inputs.

I see that my recent post may have confused a few people so I will attempt to clarify.

Most of my listening is with vinyl rather than digital and I prefer a very natural analogue sound whereas (to me) a lot of digitally reproduced music has a slight glare to treble which sounds unnatural. Different DACs can either exaggerate or lessen this. As a result I’ve auditioned and used a variety of these over the years until I found something that, in my opinion was as close to the pure ’analogue’ sound I was after. That is what inputs to the HDP-5 via balanced analogue connection.

Therefore I prefer to use the balanced XLR input where digital sources (CD, FLAC etc) are already processed so in effect the processor sees everything as analogue. Processing of digital inputs to the DAC in the HDP-5 is certainly a step up from the HDP-3 - both are very good. It’s just that I am rather picky & have a setup (using the external DAC) where it is pretty difficult to tell the difference between a vinyl or digital copy of the same album. Using any digital inputs into the DEQX DAC, treble is a little more ’brittle’ (I just did a swap to make sure I could qualify this remark - the DEQX processors are so good that we are talking small degrees here & I continue to be astounded by the life-like realism that the system produces).

note: from the DEQX product overview of the HDP-5... "provides transparent analogue pass-through.......Analogue inputs utilize Cirrus Logic’s reference ‘professional’ ADC to provide absolute transparency for analogue sources such as vinyl preamps and surround receivers"....I agree with that.

For sure, in theory removing the sequence that I use (external DAC =>A/D =>D/A =>out) should benefit from reduced processing. From living with DEQX & comparative listening for over 4 years, that isn’t the case for me.

"Roscoeiii: drewan77, Sorry if I missed it, but have you tried DEQX digital out --> external DAC --> preamp (if volume control is needed)? If so, how did that compare to the setup you are currently using ( external DAC =>A/D =>D/A =>out)?"

No I have not - My setup would require at least 3 external DACs & a
multi-channel preamp.

I have no need to change anything except daisy-chain the HDP-3 to the HDP-5 at some future point to add additional mid-bass amps/drivers (for now the HDP-3 is running a system in another room).

Yes Jeff, DEQX inspired me to build my own speakers.

I had always been impressed with Open Baffle designs because of the lack of cabinet colouration and great transient speed so I set about building various prototypes several years ago, using my original HDP-3. Once voiced exactly as wanted, I then commissioned a CNC workshop to produce the final frames in zebrano bamboo.

When you master the workings of DEQX (no mean task!), speaker building and tweaking is fascinating. I recommend going to the trouble to take measurements outdoors which produce an almost pure anechoic response (in my most recent example, windowing calibrations to 31ms before even a slight reflection, only from the mic stand). The cleaner the initial data, the better will be the final result.

Being able to use 4 preset configs with differing crossover types, frequencies and slopes enables you to listen instantly ’on-the-fly’ with music playing, although I suggest newcomers start with the DEQX defaults until you understand the various interactions. You can then go much deeper, configuring for minimum phase or minimum delay etc and learning exactly how to bring the best out of each individual driver. It’s also great that DEQX measurements treat everything downstream of the processor as one, meaning that the impact of your cabling & amplification is also taken care of by the resulting calibration - as long as you don’t change anything of course!

I learned quite fast, for instance that the tweeters in my setup had one ’perfect’ crossover point for both they & the midranges below - above this frequency there was some beaming and thickening but crossing lower, treble became subtly more brittle. Also, by trying various natural wool tweeter surround shapes & placements, measuring & listening again in-room, everything was finally clearer, more focused & smooth than any other speaker I have heard. Being able to make a change, set it into your main config and listen to music for days or even weeks before further adjustment in one of the other 3 presets means you really can be sure that changes are beneficial. Everything is also reversible or repeatable.

Please let us know how you get on & various of us here will be happy to assist if needs be. I was asked to look through the draft of the most recent DEQX manual as an experienced ’user’ by Kim Ryrie before it was published & I can confirm that it is now much more user friendly & logical to follow. It should be much easier than when I started out!

Andrew

Good to hear that you are joining the DEQX ’club’ Ozzy.

When I originally purchased an HDP-3, I used it in the same way as your forthcoming PreMate - in that case using Shahinian Obelisks (including their passive crossovers) with a Miller & Kreisel MX200 sub.

The fist time I measured, corrected, time aligned & listened was the most significant ’wow’ moment I have had with hifi & even though the quality of my setup is now a long way beyond that, I will never forget that first session.

You should be in for a treat & if you need any assistance, then please ask. As with Al, I used the expertise of my dealer, supported by several emails to Alan Langford at DEQX and then an extensive period of research, questioning and self-learning. Quite a few other DEQX users have also emailed me their config files over the years & I notice that various DEQXperts had originally set them up in a very similar fashion.... which has been reassuring for me :)

Ozzy, if it isn’t on your CD, you can also download your mic file by going to the DEQX website:

From the bar across the top of the page, choose: Owners, then upgrades from the dropdown box, scroll down to Dayton mic files & Dayton all Microphones - download (mic).

You will be asked for authentification.....
User name = beta
Password = nyquist (all lower case).

Once you unzip the folder, the file "6780EMM6-INV.mic" is in there.

As for the two different mic types, I originally used a Behringer ECM8000 (DEQX predecessor to the Dayton) with the HDP-3 & later upgraded to an Earthworks M23 before I purchased the HDP-5.

I would not worry too much about the different mic’s because the critical frequency range is going to be somewhere between 200hz & 10khz & the reference mic really comes into its own at the highest frequencies, although measurements across the board do appear to be a little more precise. My measurement routine, calibration and setup is quite OCD and therefore the benefits gained by the M23 proved worth it (I am able to use much lower levels of smoothing & greater accuracy in calibration across the entire frequency range if I choose to).

Listening to music via the same speakers based on an outdoor measurement, there is definitely an audible improvement for the M23 but it is not that great. If I had never made the later calibrations, I would still have been extremely satisfied with those from the lower cost microphone.

Does anyone think if there is a breakin time for the unit? I am using it as a Preamp so I assume like most things audio 200 hours of use time seems to be about right.

Ozzy, I see from your earlier post that you purchased a 'used' Premate so I would expect it is already broken in (if there is such a thing - the process of setup, measuring, calibrating and experimenting over the first few weeks will probably take long enough).

As for the BSG QOL, I have never seen this item before & I'm not clear what it would achieve after the Premate has done its processing. From a very quick look at a few web pages, it seems to work with phase shift. However the DEQX algorithms will correct phase and timing automatically for everything upstream anyway (via the mic measurements).

If you do plan to try this out, I would suggest downstream (before) the Premate but I recommend you set the system up without this and experiment later.

The logic behind my response is that DEQX corrects the speakers (+ Amps) & room whereas the QOL appears to deal with phase anomalies on the source recording. Adding this component between the Premate & amps will upset the measured relationship so I would not do that. 

"Thanks, If the QOL is placed before the DEQX Premate would I need to run the measurements again?"

No, the DEQX processor measures the effect of the speakers/cabling/amps downstream & the QOL is going to address source material upstream. This has nothing to do with in-room measurements.

The PreMate microphone measurement is based on a rising frequency plot created by the processor & will have no correlation with anything beforehand in the rest of your system (which is the correct way to do this).

Then, during normal listening, it will be fed a ’corrected’ source signal & it will phase & time correct everything for the speakers & room afterwards based on the chosen calibration.

.....If you added it after the PreMate (especially if you then took a measurement), the two separate phase corrections may give strange results & it’s definitely not as DEQX intended.

Yes those confidence levels should be fine. Only 3dB between L & R main speakers means your mic was fractionally off centre so look at the impulse response of both in one viewer window, zoom in and take the mid point timing as the reading. (It will probably be no more than 1 or 2 fractions of a ms difference between the two main peaks & only really visible at a high zoom level).

The best way to set mains to subs is first to align the faster sub (usually nearest to your listening/measuring position) to the slower sub, then align the pair of main speakers (average reading as above), also with the slowest sub.

Finally, take another measurement afterwards to verify & you should see both subs initial peak at the same point & the main speakers main peak now also at the same time alignment. I always find it best to open two viewer windows, one for the pair of mains, one for the pair of subs. If you try and see all 4 measurements in one viewer, the scale usually makes the sub measurements look almost flat and impossible to interpret accurately. 

No, bypass does not need any measurements - don't set a calibration or filters for this profile.

This could progress into quite a lengthy exchange & may take a while, depending on our relative time zones. What I've normally done in situations like this is have the user send me their .mzd file which I can interpret properly, make initial time alignments etc & send it back with four different profiles set - If you want to do that, use the address below

[email protected]

I'm happy to help as I well remember the frustration that can come during the initial learning process - there are a lot of parameters that interact with each other.
The software also has a lot of details that aren't totally documented. 

Andrew

nomad54: i know that Spatial (the new X-1) & Larsen make speakers specifically for DEQX users and was wondering if there are any others?

Legend Acoustics Tikandi

Using a standard M23 will not have the correct DEQX calibration file unfortunately so be very careful. It will not work without this. 

Yes. I use DEQX with OB speakers & am now building my second pair as a 4-way, powered by an HDP-5 with an HDP-3 as slave. 

I have recently completed new Open Baffle speakers utilising both DEQX processors as mentioned in previous threads. Linking master-slave by RS232 + digital cabling was straight forward. The HDP-5 controls the main speakers, the HDP-3 two subs at <50hz.

Currently I have only measured outdoors at a relatively low height because of the weight of these speakers. At a later date I will re-do this at 1m height. Rather than move the entire system outdoors I used 15m speaker cables and two interconnected 7m microphone cables (to Earthworks M23) from the music room.

New images are posted in my Audiogon profile

Yes, the software, user manual etc are available to download from the DEQX site (you will need to ask by email: [email protected] for the latest login & password to do so). 

1. Connect directly to the PreMATE DAC as these are high quality & transparent.
2. If you get an M23 from another source, you will need to have the files converted - probably by Alan Langford at DEQX & my experience is that he may take quite a while to do this & there may be a cost. I would personally not recommend it.  I asked the question before getting my own M23 but in the end bought it via the DEQX dealer with the correct DEQX file.
3. I always connect directly to a DEQX processor when using subs to achieve the most accurate time alignment. This feature is excellent, minimises other equipment in the chain & volume is locked in with the main speakers. The DEQX software allows you to adjust time delay (main speakers to subs), phase, relative volumes & equalisation anyway. If you want to offset any lacking bass from the source, you can set the four remote control presets to progressively higher levels of sub volume. This works really well & is what I do.