Is DEQX a game changer?

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.

I've been trying to arrange a DEQX home audition. Came close to setting something up tomorrow, but vacation schedules got in the way. Hopefully, soon after Labor Day.

Bob, if you read through the Sloped Baffle thread, you might get a better sense of what the DEQX device can do. The beating heart in NOT room equalization ... it is time coherence correction.

Most speakers on the market are not time coherent. They may be phase coherent at the x-over points, but not time coherent. The DEQX measures actual time incoherence of one's speakers and makes corrections by delaying various slices of the sonic spectrum to align the output of the various drivers. Room EQ is just an added plus.

If you look at most of the Stereophile speaker reviews, one of John Atkinson's tests involves a time coherence analysis. What you see in most cases is the tweeter reacting first, then the mid driver, followed up by the woofer. Sometimes, one or more drivers are wired in reverse polarity to achieve phase coherence at the x-over points.

So in the more usual case, the DEQX will slice up the sonic output of the source signal into 4000 segments. Then, using a very sophisticated chip, the DEQX will delay (up to 10 micro seconds) the various segments in order to achieve time coherency. Since the tweeters generally respond before woofer, the sonic spectrum covered by the tweeter may be time delayed vis a vis the woofer. The same approach is applied with the mid driver.

Back to the Sloped Baffle thread -- Roy Johnson of Green Mountain Audio has posted some great articles that explain why most speakers are not time coherent, the impact on the summed wave form, and how he attempts to effect corrections. In most cases, the fix, or his fix, is to use 1st order x-overs and to recess the tweeter and mid driver vis a vis the woofer so that the voice coils of each driver are perfectly aligned in vertical space.

The DEQX does this electronically.

So, I'll report back as soon as I can arrange my home audition.

@Bob -- just wait until I home audition the DEQX. As seems to be the case with a great many audio issues, there is a divergence of opinion.

Yes ... on the hand, the time coherence opponents say that most people can't tell the difference between a time coherent speaker and one that is not time coherent. The naysayers may add that like all engineering problems, trade off are made. Perhaps there is greater flexibility in driver selection in the time incoherent space.

OTOH, folks like Bombaywalla, Roy Johnston, Rich Vandersteen, and the late Jim Thiel urge us fence sitters to drink the Kool-Aid. And as stated above, Roy has written some really good white papers that explain time coherence and why it so important.

At this point ... I am still sitting on the fence and will continue to do so until the US DEQX sale reps sets me up with a home demo.

So ... to my fellow fence sitters, hopefully sometime after Labor Day I will be able to post my reactions.

Cheers

BIF

Gotta tell ya. Getting the DEQX audition arranged up has been a frustrating PITA. I'll be generous and attribute it to the summer time and vacations. But if it's half as good as it's hyped, it is an important tweak that serious audiophiles should be thinking about.

As I said, hopefully, shortly after labor day and I'll have something to report.

If DEQX doesn't do a better job of getting a more responsive dealer network established, I fear crash and burn.

I'll have more to say after the audition.

@Bob ... time coherence is not just pure BS. Manufacturers make design decisions based on pluses and minuses. I don't enough about the engineering or the cost accounting math to weigh in. But I'm sure that if top companies like Focal, Revel and Magico could figure out a way to push the square peg into the round hole and solve every problem, they would do it.

It's all about trade offs. Poor Roy Johnson and GMA. I showed my exterminator a pic of Roy's top of the line speakers, and he was ready to pull DTT out of his truck. LOL!!

I'll be back.

@Bombaywalla, not idle talk re romex. Summer has been very busy time. Also, trying to get the DEQX guys to get their act together has been a major PITA. The US rep said after Labor Day. The reasons for the delays are not worth repeating ... too boring.

I haven't forgotten about the DEQX and will report back.

@Lew ... not sure that's the way it works re the self powered sub and my Ref 150/mains. But I'll report back.

@Unsound ... not sure I'm the guy who can respond to your concerns.

I'll copy and pass these Qs along to the US rep.

BIF

Ozzy ... the DEQX rep is coming to my house on Monday to do a home audition. Let's hold judgment until I report back. I am on the fence right now.

As to self-calibration ... from what little I understand about the device, I think it is a near impossibility for a non-techie to do the calibration. But again, I'll have more to report after the audition.

I suspect Al (Almarg) may find my anecdotal report to be of interest.

Thanks Forrestc ... still trying to drag the DEQX rep out to my house. Maybe he's using a strategy of sales foreplay. Dunno. Hopefully this week.

Btw, your point that "Kim states that with the DEQX, speaker designers should focus on producing the lowest distortion driver possible and not to worry about phase and group delay issues since the DEQX is quite capable of successfully managing these issues on its own" makes much sense.

My Paradigm S8s (v3) use well made drivers that produce very low distortion. My main gripe has been the crazy impedance and phase angle curves. Fortunately, my Ref 150 has the muscle and robust power supply to handle that roller coaster. I use the 4 ohm taps which "taps" (pun) down voltage output variations as a function of frequency response to a small amount.

I am optimistic that the DEQX will make a big difference ... if I can get the rep to engage.

Hopefully, will report back soon.

Unsound and Ptss ... the DEQX demo is scheduled for Monday the 15th. Holding judgment until then.

@Unsound ... you raise a fair comment and I will ask the rep on Monday about post sale service.

@Ptss ... what choice does he or I have. It's the same basic genre of question about the meaningfulness of B&M store auditions. At least I'll have a chance to see the DEQX perform on my system in my house with my speakers.

Yes, this is an expensive model. But because the device is NOT plug and play, there is no choice. The devise needs to be custom calibrated remotely by the tech who resides in Colorado.

Part of me says, waive bye-bye to my money when the rep leaves my house with my check. Another part says that I may be making a very important and worthwhile upgrade to my system.

I'll be back. It's been slow going, but I'm getting there.

Fyi folks ... the DEQX rep scheduled the DEQX tech guy in Colorado (Larry) to be on call to take the calibrations to the final step. The rep is bringing a mic and all of the other paraphernalia that will be needed to calibrate my system for time coherence and FR EQ.

Optimally, the time coherence measurements are best made in a sonically "dead" environment. Short of an anechoic chamber, I think the next best place is outside. The anechoic chamber is not an option and I doubt schlepping the speakers and amp outside is an option either.

So, maybe I'll get a 90-plus percent result??? Again, I'll know more after the Monday audition.

Drewan77 ... your experience and reactions are encouraging.

Btw, the rep is using a DEQX Pre Mate. I was more interested in the DEQX Mate, but the Pre Mate has DAC capability. So maybe, I'll be able to finally dip my toe into other digital formats, like SACD and Hi Rez downloads.

My interest is technically piqued.

Psag, illuminate me. How the heck am I going to move a 100 pound speaker and a 75 pound amp outside. And what about power connections. I'm sorry ... I'm just am having a problem figuring out the logistics.

DEQX Update: I used an extra XLR connector from another application to hook up the Ref CD-8 CDP digital output directly into the DEQX via the XLR D4 input socket. The acoustic sound presentation is similar, but the DEQX DAC function produces a somewhat sharper image and sound stage.

Getting a little nervous here. What happens if I try a direct DEQX analogue hook-up from my phono pre???

What happens to my ARC Ref 5 SE???

Al ... are you following this? I need some independent validation. I am trying to adapt to some major paradigm shifts here.

Bombaywalla ... my DEQX appointment was cancelled and rescheduled for next week. I was tangled up with urgent client matters that HAD to be sorted out on the 15th, which is the final due date for calendar year corporate tax returns that on extension. So, the rep rescheduled for next Monday, the 22nd.

Looking forward to being amazed.

BIF

The DEQX home demo was completed last night. I am buying the DEQX.

Not being inclined to the use of vivid hyperbole, I do not think the DEQX is transformational. But I do think the improvements are considerable and significant enough for me to spring to buy the DEQX.

I will follow up with a more detailed report after I finish drafting and editing my thoughts.

More to follow.

BIF

Forresstc .... I will post a more detailed report that lays out the details of my DEQX audition. It took 2 sessions. The first session was worthless because of serious room issues and my speakers are just too large for the room.

Plus, the second session involved hooking up my sub directly into the DEQX device rather than from my preamp's main #2 output. This permitted the DEQXpert to more effectively make compensating adjustments by crossing over my self powered sub at 120 Hz. Probably improved bass tightness because the DF in my sub is pretty high. My sub is a self powered solid state job.

I am dubious that an average Joe could extract as much out of my DEQX as the DEQXpert. Too many adjustments and too many beasts to tame. Also, many of the time alignment and room EQ adjustments were made based on the DEQXpert's anecdotal experiences.

For example, he did not attempt to achieve a ruler flat EQ curve. He said that twisting the drivers beyond a certain point would result in a negative yield.

So ... IMO, unless one is really tech saavy, I'd recommend paying the extra fee for the DEQXpert service.

Forrestc, stated differently, beyond a certain point, continued tweaking yields diminishing return.

Drewan ... I bought the rep's demo, which was a PreMate. So I have DAC capabilities ... to be explored and understood in the coming days and weeks.

Bombaywalla ... the DEQX device can cut-out the correction circuit and step out of the signal path ... if you believe that is truly possible. If so, I can compare the DEQX correction on the fly --- in and out. It "appears" that when the DEQX is cut-off, the rig's SPL seems lower as compared to when the DEQX is engaged.

The DEQX guys explained that the SPL isn't really lower. Rather, when the DEQX is cut-off, I am turning up the gain to try and capture the missing "X-factor" correction the DEQX adds. In fact, when the DEQX is engaged, I can turn the gain down a little and the presentation is just fine.

As I understand the DEQX guys' explanation, an important "fix" is in the midrange frequencies, which are most noticeable when corrected. So ... when the mids are time corrected and room equalized, I simply "hear" the music qualitatively better. Ergo, I don't need to crank up the SPL.

The DEQX seems to have tamed my rig. It would sure be helpful if other audiophiles could listen to my rig and validate what I think I hear.

Al (Almarg) ... if you're ever in my neck of the woods, feel free to stop by and have a listen. I greatly value your opinion.

Al, right now, my vinyl and CDP are connected in usual fashion to the ARC Ref 5 SE pre. The DEQX is inserted between the Ref 5 and the Ref 150 amp. The DEQX is "twisting" the signal there.

As I said, it's hard to know the extent to which the DEQX is affecting the sound by being in the signal path. The DEQX guys think the effect is minimal. But, regardless even if that is not so, the game is about trade-offs.

Now ... what will be interesting is if I use the DEQX as a DAC. Then my ARC CDP will feed a digital signal directly into the DEQX and end-run the ARC pre.

Btw, I understand my phono pre can feed an analogue signal directly into the DEQX too. That would obviate the need for my ARC preamp.

Well stated Drewan.

Al, you and I are both old enough to know that some questions are best not asked. I'm "freeze tagging" on the DEQX's analogue functionality viz my phono. The thought that my Ref 5 SE could be an irrelevant artifact is too difficult to bear.

I had the same reaction when Excel/Lotis spreadsheet software obsoleted 14 column spreadsheet paper. To this day, I refuse to use Excel. I ask the kids to run my spreadsheets when I need that work done. I love my 14 column spreadsheets, white vinyl eraser and Pentel .5mm mechanical pencil. Even to this day, nobody can run a "10-key" faster than me.

Drewan ...can I use the transport in my CD-8 to play SACD discs? I don't know what the bit/FR is with SACD or other high resolution discs. This is new territory for me. I think redbook CD is 16 bit/44.1 KHz. What is SACD?

What about hi-rez computer downloads? I have no idea what is out there.

Bombaywalla or perhaps Drewan77 --- what is the DEQX's digital capabilities?? Can I use the CD-8 as a transport and the DEQX as a pure DAC to play SACD?

Btw, just updated my comments on the "Absolute Redbook DAC" thread. Too long to repeat here ... but I think the redbook DAC functionality of the CD-8 (with gain circuit) and running the analogue signal through my Ref 5 SE pre into the DEQX analogue input is a rough draw as compared to running the signal directly into the DEQX's digital input off the digital output of the CD-8 (san gain circuits of both the CD-8 and Ref 5 SE, and of course san CD-8 DAC).

Btw, still holding that the DEQX's time alignment and room EQ corrections are significant improvement. Just talking about the DEQX's digital DAC capabilities here.

Cerrot ... your comments, from an aspirational perspective, are valid. But aspirations do not necessarily align with reality. I suggest that you read the many posts in the "Sloped Baffle" thread. In particular, read Roy Johnson's many posts about 1st order cross overs and using sloped baffles. I recall that Bombaywalla and a few other similar thinking folks have also posted some very insightful comments.

Just an fyi, most speakers that use passive cross-overs are NOT time coherent, even if they are phase coherent at their respective x-over points. The physics is explained in the "Sloped Baffle" thread. Roy Johnson's White Papers are excellent resources as well.

To my knowledge, there are only 3 conventional driver speakers on the market that purport to be time and phase coherent; namely Vandersteen, Thiel and Green Mountain Audio. There may be others but I don't know which brands they might be.

The 3 brands mentioned above share several common design parameters. One -- first order crossovers (roll-off is at a 6db per octave slope); two -- sloped front baffles to mechanically align the voice coils of the various drivers; and; three -- drivers that operate over a wider pass band as compared to more conventional drivers.

In the case of the 3rd point in the preceding paragraph, drivers cross that over to each using a 1st order cross-over necessarily must operate over a wider pass band. By comparison, my Paradigm's use 3rd order crossovers between the mid and tweeter drivers. I believe that equates to a 24 db roll off rate. In short, each driver's operational pass band is much tighter.

While time coherent design features provide obvious advantages, they present design challenges as well. For example, drivers that operate over a wider pass band tend to be less linear. Also, their output may become congested at high SPLs and or when playing complicated musical passages.

My point is that there is no magical solution that solves every design parameter perfectly. So, be it going the Vandy, Thiel or GMA route, or using a DEQX with a more "conventional" speakers, or just living with time incoherence, ... there are trade-offs.

Welcome to our hobby.

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?

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.

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.

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

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.

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.

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.

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.

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 :)

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."

Kal,

Can you answer the OP's question, "Is DEQX a game changer?" or do we have to wait for your report?

Andrew (Drewan77) --- been following the last several posts. As you know, I just bought the PreMATE. Larry, the DEQXpert, set it up. Interestingly, he cut the self powered sub woofer off at 120 Hz and let the speakers' passive woofers take it from there until they crossed over to mid-driver at 200 or so Hz.

Based on Larry's measurements, my sub woofer is pretty flat down to about 13 Hz, which is pretty low. Kinda weird, but the speaker's woofers are covering about 80 to 100 Hz of bandwidth. So, the bottom line here is that the heavy bass lifting is being handled by the sub woofer.

There is an added plus ... namely that it takes "pressure" to delivery power off my amp and shifts it to the subwoofer, which has a built-in amp rated at 3400 watts max-Q. I've tripped my circuit breakers plenty of times.

All-in-all, I think my speakers sound better than before. When I cut the PreMATE out of the circuit (P0 button), the sound presentation is muddy and imaging is smeared. When engaged, sharper imaging, better transients, nicer sounding musical presentation.

I would like to explore and play with the PreMATE's considerable functionalities. Problem is that the owner's manual is not very user-friendly and is accessible only on-line or off a disc. Plus, I am not very tech or computer wise.

Sure wish I could spend some more time with Larry the DEQXpert.

Bruce

Unsound ... not sure if this post is responsive to what you just posted. In my case, I am using the DEQX principally for its time alignment and room EQ functionalities in analogue mode. And as many have already posted, the DEQX works very well in these functions.

Yes ... the DEQX PreMATE has an onboard DAC. In fact, as I posted somewhere above, my "redbook" ARC Ref CD-8 CDP is hooked up to the PreMATE via two modalities: (1) analogue through my ARC Ref 5 SE preamp in "normal" analogue fashion and (2) digitally via the digital output of CD-8 directly into the PreMate's XLR input. In the later case, my CDP is acting merely as a transport and the PreMATE is the DAC.

I have not come to a unequivocal view as yet whether I prefer the analogue or digital hook up for my CD-8. The ARC CD-8's onboard DAC is based on a Burr Brown 1792 (I think) chip and is very good. The DEQX's DAC is based on a Burr Brown 1795 (I think) chip and is also very good and sounds very similar to the CD-8 albeit a little different. Just not sure which I like better.

My point is that while the DEQX PreMATE can do a more than just time alignment and room EQ, the foregoing functionalities are its signature

Thanks Al. Interesting point. Admittedly, I have an irrational bias (pun) to using the DEQX in analogue mode. That is, my CDP is hooked up to my Ref 5 SE preamp, and the DEQX is inserted in between the Ref 5 and my amp. I suppose I can't bear the thought that my Ref 5 is no longer needed.

Al ... I'll check the sound playback on a with and without basis. As far as ground loops are concerned ... nothing I can discern at this point.

Now ... the cross talk point may be relevant. At times, it seems that my CDP is playing in "mono'ish" mode. I wonder .... uuhhm.

Cheers,

Bruce

Ozzy,

I'll take a crack at Questions 2 and 3.

Q-2: Maybe. It depends on the significance of the room interactions with your speakers. My listening room/basement is acoustically terrible. I had to move a lot of stuff around. But the results were well worth the effort.

But look at it from another angle. If your room is really screwing up the frequency response of your speakers at the listening position, and the interactions are so significant that the DEQX will only partially tame the problem, you are losing out on a lot of potential improvement.

In my case, imaging was smeared because, in effect, I was listening to two different speakers. The FR of the L and R speakers were way off. Having said all that, you really won't know what (if anything) needs to be done until the DEQX runs its sweeps and the room effects are measured.

Q-3: If you're a techie, you might be able to slug your way through the set up. Andrew (Drewan77) has become quite facile doing his own set ups. But in my case, I wouldn't touch it. I worked out a comfortable fee arrangement where the DEQXpert did everything over the internet with my PC. Set up took over 3 hours!! And btw, he only "tamed" my speakers. They are NOT perfectly matched or flat. The DEQXpert made judgments based on his technical skill and empirical experiences.

Ozzy, let me just add one comment that is really obvious but important to emphasize. Even one owns $200,000 Wilson Alexandria speakers, if the room is tugging the FR of the speakers all over the place, I can't see how it is possible to appreciate what your speakers can do unless something gives.

That might mean serious room treatments and/or a DEQX or similar room EQ device to tame the room acoustics. Let's face it, most of us don't listen to our rigs in an anechoic chamber. So, IMO, this is a very important consideration.

Just finished an hour and a half fine tuning session with Larry, the DEQXPert. At his suggestion, I move my listening couch back a little and he re-tuned my system. Definitely better. He also gave me a setting option with a slight bass boost, which is kinda nice.

I'm still a DEQX believer. I'm two thumbs up for the DEQX.

No way I could have made the fine tuning adjustments by myself.

Cheers.

BIF

Ptss ... better imaging and sound stage. More pleasing presentation from a tonal perspective ... meaning less harsh sounding. Basically, Larry spent a little more time smoothing out FR kinks from room effects. He didn't touch the original time alignment adjustments.

I cannot overstate how significant room effects can be. IMO, spending a fortune on speakers will not solve problems caused by a lousy room.

Again ... I want emphasize. Larry did not adjust my speakers to be ruler flat. He further refined the "Taming of the Shrew," which is my speakers and room. Perfect -- No! Better -- Yes!!

Andrew (Drewan77) ... I get you point. But, Larry does this for a living and no doubt has volumes of anecdotal experiences upon which to base his judgments.

Perhaps, just for laugh and giggles, you and I can try to recheck the time alignment measurements of my speakers. We both may find it to be an interesting exercise. I don't want to mess with Larry's room EQ work though.

So far, I think the biggest bang for the buck lies with room EQ. That is what has the greatest impact on imaging and soundstage and tonal presentation.

I concede that time alignment makes for purer, more "honest" tonal reproduction, but nothing messes up what comes out of the speakers more than a screwed up FR, further twisted by room effect. IMHO.

Lewinskih01 .... you wrote:

"I can't remember the scope of time alignment in your system. Is it subs-to-main speakers, or are you using the active XO in the DEqX and aligned your mains drivers and also the subs? This would help put your comment above into perspective."

Yes, Larry the DEQXPert time aligned as best he could my self power sub and my front speakers. I say "as best he could" because my speakers' woofers are in opposite polarity from the tweeter/midrange. I seem to recall he had to make compromises.

My DEQX is the PreMATE. It does not have an active x-over function. The HDP-4 is the top of the line unit and it does have active x-over capability.

Now ... as regards time alignment ... I may have overstated or perhaps understated its importance. Larry did time alignment on his first pass two months ago. During the second pass the other night, he fine tuned room EQ. There were additional improvements achieved as I mentioned above.

Your question touches on the narrower point re the importance of time alignment as a stand alone attribute. I'm not sure I can honestly answer the question because Larry corrected both attributes on his first pass: time alignment AND room EQ.

I'll defer to Andrew (Drewan77). Andrew is super facile with his DEQX and can probably speak to the importance of time alignment as a stand alone attribute. I imagine he would have to do a "with" and "without" comparison.

My bottom line is this: my system sounds better WITH the DEQX in place. Larry "tamed" my speaker's time alignment shortcomings and room EQ effects. Perfect -- NO. Better - YES.

Personally, I think a "DEQX-type" unit is a must for a serious hobbyist who dropped a lot of bucks into their rig and who cares about the sound of the music playback.

I question out loud how folks who spend a small fortune on top of the line speakers can even know how good their speakers sound if they have a screwed up room. So, even if one owned time aligned speakers like Vandies or GMAs, all the time alignment in the world will not fix a screwed up room.

FYI:

Just got a letter to Marc Mickelson of The Audio Beat published, here:

http://www.theaudiobeat.com/letters.htm

I hope Marc gets around to reviewing the DEQX.

I can't overstate how important and decently priced this piece of kit is for one's audio toolbox. Considering what some are willing to pay for cables and other tweaks, when one considers what the DEQXC can do, it's a no-brainer decision, IMO.

Bruce

Ozzy ... hard to say what new technology will bring. At this time, unless one is very tech savvy, I think to get the most of the DEQX, one will need the help of the DEQXPert. Just too many variables and judgments in play.

Kal, you just reviewed the PreMATE. Does it have any auto adjust feature that you can push a button and the DEQX does its thing?

Even if it does, you still gotta move the speakers and mic around in order to time align your speakers.

Ozzy ... right now I admit set-up is tedious. But it only takes about 3 hours and then your done. IMO, the initial inconvenience is worth the gain.

Kal ... your thoughts??

Kal, I reread your review. Your comments are consistent with my anecdotal experience.

DEQX really needs to do a better job with a user-friendly instruction manual. Perhaps, even default "(recommended)" settings and promsst for the non-tech user.

Even still .. a great addition to the audiophile's tool box.

Roscoe, an A'gon audio pal is thinking about picking up a DEQX. I'm sure he'll be quite interested in reading your comments.

I bought the PreMATE in September and am satisfied with the results.

Btw, as I am sure you know, the DEQX does BOTH room correction and time coherence alignment.

Are you planning on using the DEXPert service. I recommend that you do ... unless you are very, very technical.

Roscoe ... any other early impressions?

Ptss and Roscoe ... double agree. I've worked with Larry Owen, the DEXPert, on a couple of occasions setting up my PreMate. 3 hours "ain't nuthin." Larry knows all the tricks to get the most out of the DEQX. In for a penny ... in for a pound.

Roscoe ... how are you making out with your DEQX?

Roscoe ... sorry but your response is not adequate. Tech experts like Al (Almarg) need more specific data. Please elaborate on your reactions. LOL ;-)

Are you giving any thought about asking Larry, the DEXPert, to help you fine tune the set up? Larry and I did two set up sessions and it made a real difference.

And yes, drop the $25 bucks and buy a mic stand.

Al. did Nyal mention whether the revisions would be made to the rest of the product line. As you know, I bought the Premate in September. I wonder if the revisions affect the Premate. Also, did Nyal tell you what the revisions are?

This reminds me of the early days of PCs when Intel was constantly upgrading its CPU chips from the 286 to the 386 to the 486 to the Pentium and so forth. By analogy, I think DEQX is still in its early development stage and who can say where it will wind up.