"If you don't have a $200k [speaker]..."

[Audiohertz2]

Well, according to Stereophile step response data…they failed. He should have followed after Jim Thiel or Jon Dunlavy if he had wanted to minimize timing differences or introduced a digital processor.

The alignment could look off due to mic proximity , what is obvious is that its not phase coherent with opposite polarity being used for tweeter but it is time coherent after ..!

So no this one test is not a full test on time alignement IMO

 

[Ron Resnick]

Physical time-alignment[edit]​

In this technique the drivers are physically offset such that their acoustic centres lie in the same physical plane. This technique is used when no other means of time alignment are available or meant to be used. It simplifies setup for the end user in that they do not need any special electronics to align the drivers. However, this technique requires that the exact depths of the acoustic centres be known at design time, so that the physical offset may be introduced in the front panel of the speaker where the drivers mount.[6]

A common way to do this is so that the front-panel has a "step" (as shown in the above image) where the tweeter mounts at some distance behind the woofer. This step can cause more errors in summing than the time delay between the drivers due to the diffraction of the tweeter's sound waves around the step.[7] Sloping and rounding the edges of the step helps in reducing diffraction, but it cannot be eliminated completely. Also, the more gradual the slope, greater is the vertical separation between the drivers, which in turn again causes thinning of the lobe (i.e., increase in vertical directivity) at the crossover frequency.

Another way to introduce physical time-alignment without having to physically shift the tweeter backwards is to tilt the speaker itself upwards (or have the front-panel sloping instead of vertical). This method will cause the physical on-axis plane itself to be tilted upwards - so it virtually brings the physical plane in line with the required on-axis plane. However, now the listening position is off-axis relative to either driver at all frequencies.[7] This is the simplest of all methods (especially tilting the speaker itself upwards) in that it can be done for any speaker and lends itself more easily to setting up the speakers by trial-and-error.

I am certainly not a technical person and I never stay in a holiday inn, can someone explain the difference that is being discussed to me Please?

I dont know if this has anything to do with what I heard in so many cases and I know that one for sure does not require a 200k speaker to play great music and get incredible sound.
I do know that the larger the speaker (normally more expensive as well) the more exacting it is to get the performance and room matching correct. I have heard many large speakers and most of what I have experienced is to be honest mediocre, however this is always or almost always becuase of bad set up ( wide area to discuss for some other place). There are bad speakers, there are not great sources and electronics however more often than not its the room and the set up withing that space that is the issue.
I have heard Wilson large speakers sound good, not often btw but I have, the smaller speakers they make which are less complicated to set up and IMO are more ususable in "normal" spaces are popular and people get good results and like them. They may not be my choice but one size never fits all. I want to say this one more time becasue I love taking shit from people if you have not experienced a really well set up and calibrated system in a purpose built room that is established and dialed in then you are missing something in your audio knowledge and experience. One does not know what one is missing until.........
IN the case of these huge multi driver, multi adjustment type speakers they are universally a pain to set up and IMO in the Wilson case there are far more variables than most.
This IMO is why there are such wide swings of opinions, experiences and even "facts" spewed around.

Thank you, Elliot.

I can use Google to find Wikipedia also. But I was very careful to ask of a Wilson owner what is his understanding of what Wilson Audio specifically means by this term.

 

[Elliot G.]

Thank you, Elliot.

I can use Google to find Wikipedia also. But I was very careful to ask of a Wilson owner what is his understanding of what Wilson Audio specifically means by this term.

Ron , there are three terms being kicked around and I don't understand the differences I looked up the actual definition to try to get a baseline.
I am not questioning btw just want t understand the parameters in the discussion.
I'm a listener not a scientist but I have a basic understanding and thought that mechanically aligning the drivers was trying to time align.
Dahlquist had an TA example and what I learned form that is what I used to comprehend this. I just wanted to see if there was stuff I was missing.
I owned them a million years aga and JD was a constant visitor and friend.

 

[Ron Resnick]

Ron , there are three terms being kicked around and I don't understand the differences I looked up the actual definition to try to get a baseline.
I am not questioning btw just want t understand the parameters in the discussion.
I'm a listener not a scientist but I have a basic understanding and thought that mechanically aligning the drivers was trying to time align.
Dahlquist had an TA example and what I learned form that is what I used to comprehend this. I just wanted to see if there was stuff I was missing.
I owned them a million years aga and JD was a constant visitor and friend.

I understand on all points. I don't understand the differences either exactly.

But I am curious to know what Wilson Audio itself specifically means by "time-aligned" -- how Wilson Audio itself defines this term.

Perhaps WBF member metaphacts can tell us.

 

[andromedaaudio]

I cant speak for Metaphacts , but i think wilson is trying to achieve that the sound from all drivers reach the listener at the same time , hence all the adjustment possibilities
Its widely accepted sound travels basically at the same speed at all freqs through a certain medium , in our case air.

(Ps In my personal view all units being electrically in phase is far more important though , if the above was that important placing a sub in the corner would be totally unacceptable
)

Quote:
One of the more important properties of sound is that its speed is nearly independent of frequency. If this were not the case, and high-frequency sounds traveled faster, for example, then the farther you were from a band in a football stadium, the more the sound from the low-pitch instruments would lag behind the high-pitch ones. But the music from all instruments arrives in cadence independent of distance, and so all frequencies must travel at nearly the same speed.

14.1 Speed of Sound, Frequency, and Wavelength - Physics | OpenStax

Sound is a wave. More specifically, sound is defined to be a disturbance of matter that is transmitted from its source outward. A disturbance is anythin...

openstax.org

 

[andromedaaudio]

Speaking as a designer the way wilson makes their speakers makes them more costly to make off course .
Many little boxes which need to be spray painted with adjustment facilities and extra cables / connectors etc
Its also possible you loose to a certain extent the rigidity of a monocoque design
All about trade offs

 

[morricab]

The alignment could look off due to mic proximity , what is obvious is that its not phase coherent with opposite polarity being used for tweeter but it is time coherent after ..!

So no this one test is not a full test on time alignement IMO

Yes, the step response is THE test for time coherence. If it fails this it’s not time coherent/aligned or coincident…

 

[microstrip]

Yes, in the Alexx V review and what he has done is invent his own terms to try to justify bogus claims of time alignment by Wilson and a few others.

What he calls time coherent is where on driver starts, stops and then the next driver starts, stops and then on to the next driver.
Wilson Audio Specialties Alexx V loudspeaker Measurements | Stereophile.com

View attachment 114232


As can be seen the midrange starting about 0.2 ms after the tweeter and the lower mid about 0.75 ms after the tweeter and the woofer about 1.0 ms after the tweeter. While this is not a lot of time delay compared to some speakers, it is not time coherent, coincident or whatever else JA wants to call it.

A time aligned speaker will have all of these drivers moving in the same phase (either all positive or all negative) and all will start AT THE SAME TIME as the tweeter so as to make a right triangle, like this one from the Vandersteen Treo, a quite good sounding, if inefficient, speaker I have heard at a show with an all Brinkmann system. Given the speaker was I think the cheapest part of the system, it presented itself very nicely indeed. The next year they used a YG Caramel, which is probably 3x the price in the same room with same gear and it sounded distinctly worse.

View attachment 114233

The question is not whether one can hear this difference or not but why a company would claim time alignment (and even allow a bunch of very expensive adjustments) when the data shows demonstrably that they are not time aligned. I think JA is running cover for Wilson and some others who make these bogus time alignment claims by coming up with confusing terminology. Everyone USED to know what time alignment means...JA has now invented two terms that muddy the water.

View attachment 114240

Dunlavy SC-IV
"Look at the SC-IV's step response in fig.4. Pretty ideal—the outputs of all the drive-units arrive at the microphone at pretty much the same time. This, by definition, is time coherence. As a result, the SC-IV is one of the only two loudspeakers I've encountered that can produce a good squarewave shape. "

Here we see, in an old Dunlavy review, JA using the term time coherence in a very different way from what he uses it in the Alexx V review. He now would call this time coincidence but in the older review he is still using the accepted terminology and has yet to invent his own. As this review is from 1994, I guess Wilson had not yet taken over the audio world...

From the Alexx V review:
"But other than those admittedly minor issues, the Alexx V's step response is time-coherent on this axis (footnote 2), implying optimal crossover implementation."

" I should clear up some readers' confusion about my use of the terms "time-coherent" and "time-coincident" with multiway loudspeakers. The latter means that the outputs of the drive-units arrive at the nominal listening/microphone position at the same time. The step response is therefore a right triangle—a vertical rise from zero with then a slow decay to the timeline. This is very difficult to arrange—the only dynamic speakers I have measured that were truly time-coincident have been various Spicas, Thiels, Dunlavys, and Vandersteens. By "time-coherent," I mean that when the crossover's phase shift in the crossover region and the different distances of the acoustic centers of the drive-units from the listening/microphone position are taken into account, the result is a step response where the decay of each unit's step smoothly blends with the start of the step of the next lower in frequency. To the ear, the difference between perfect time-coincidence and perfect time coherence is relatively minor."

See, he has changed the definition rather dramatically from the, more correct, usage with the Dunlavy, Thiel and Vandersteen reviews.

I for one think it matters and I heard a convincing demo once with Dali Speakers where they first played the speaker with its normal non-phase/time aligned crossover. Then they performed digital correction only on the impulse response (no equalization of drivers FR) and it made an already decent speaker dramatically better. If one had a digital only system, I think that as long as you can choose your own DAC (the TACT system used at that time only had analog out) most speakers would significantly benefit from such a time alignment.

I also heard an earlier demo with B&W Nautilus 800 speakers, which used high order slopes and were far from time coherent, where they had done the digital correction to the digital recording (this was before real-time processors were commercially available). They played the recording as it was originally and then with the time compensated recording. The transformation in the speaker was astonishing.

Thanks for your time. What is described is accepted practice in this industry, accepted by many manufacturers - it was also discussed in interviews in TAS including audio designers others than David Wilson - JA wrote it long ago before the Alexia V - he was now just summarizing it in your fast google quote.

Feel free to go with your personnel anti Wilson Audio crusade - we know success always attracts negative comments, it is part of life.

 

[Lee]

Similarly related, I recall not that long ago where it was purported that, when it came to digital and timing errors, or lack of continuity of timing where it was believed that humans' ear / brain was not capable of discerning such minute differences. Yet, when engineers and consumers started experimenting with pro - audio clocks (Antelope Audio comes to mind) the benefits were indisputable. Now, here we are with oven - baked crystals and uber - accurate clocks in any DAC worth its salt.

Excellent point!

 

[chuck]

But this is my point. You get less precision in soundstaging and other sound characteristics when you cannot adjust the drivers.

I can't go along with that statement. I had Wilson Alexandrias (X2S2 then XLF) for several years then traded for YG Sonja XVs when they proved a bit better than the Wilsons on precision soundstaging and other sound characteristics. The YGs do not have separately adjustable drivers.

 

[Lee]

I can't go along with that statement. I had Wilson Alexandrias (X2S2 then XLF) for several years then traded for YG Sonja XVs when they proved a bit better than the Wilsons on precision soundstaging and other sound characteristics. The YGs do not have separately adjustable drivers.

How do the Sonja XVs handle time alignment? What’s the rest of your system?

 

[sbo6]

I can't go along with that statement. I had Wilson Alexandrias (X2S2 then XLF) for several years then traded for YG Sonja XVs when they proved a bit better than the Wilsons on precision soundstaging and other sound characteristics. The YGs do not have separately adjustable drivers.

FWIW - I like Wilsons, they're clearly a top - notch brand, but they've simply never been my flavor, if you will. However, the best, most pinpoint imaging and spacial cue definition in all three dimensions I've ever heard came out of a very high - quality system driving XLFs. And I, like many of you have heard quite a few very high - end systems.

 

[chuck]

How do the Sonja XVs handle time alignment? What’s the rest of your system?

I won't speak for YG. I asked YG that question and will let you know if they answer. The closest answer I could find on their website is: https://www.yg-acoustics.com/wp-content/uploads/2022/04/YG_DualCoherent_20.pdf

Rest of system: currently Boulder 1110 and 3060; Playback Designs MPT8 and MPD8. At the time I switched from Wilsons: ARC Ref40 instead of Boulder 1110.

 

[morricab]

Thanks for your time. What is described is accepted practice in this industry, accepted by many manufacturers - it was also discussed in interviews in TAS including audio designers others than David Wilson - JA wrote it long ago before the Alexia V - he was now just summarizing it in your fast google quote.

Feel free to go with your personnel anti Wilson Audio crusade - we know success always attracts negative comments, it is part of life.

I am only anti-BS…if Wilson peddles that well…

Also, I don’t let some audio journalists dictate physics to me.

One might surmise that JA’s change of view on time coherence has been influenced by something other than physics over time.

 

[Al M.]

FWIW - I like Wilsons, they're clearly a top - notch brand, but they've simply never been my flavor, if you will. However, the best, most pinpoint imaging and spacial cue definition in all three dimensions I've ever heard came out of a very high - quality system driving XLFs. And I, like many of you have heard quite a few very high - end systems.

Who wants pinpoint imaging? Live music images are not pinpoint, even though localizable. At least as long as you are within a range from the performers where direct sound still is a larger factor than reflected sound.

 

[Alrainbow]

Great imaging to me is a hallmark very much needed. not all recordings have it but all systems need it. same on tone and timbre it’s a system as such should be all in place. I love live stuff why it hides flaws Ina system not setup properly lol.

 

[microstrip]

Who wants pinpoint imaging? Live music images are not pinpoint, even though localizable. At least as long as you are within a range from the performers where direct sound still is a larger factor than reflected sound.

Unfortunately people misuse the words pinpoint - in general audiophile language used by many reviewers since long pinpoint means ability to be localized, not small size point like images.

And sorry, live music becomes pinpoint mostly because of the visual stimulus - sound reprodcution aims to recreate it. Sound engineers and sound reproduction scholars wrote a lot about it.

 

[sbo6]

Who wants pinpoint imaging? Live music images are not pinpoint, even though localizable. At least as long as you are within a range from the performers where direct sound still is a larger factor than reflected sound.

If it's what's on the source material, don't we all want it?

 

[microstrip]

Dear Francisco, Lee, Marty:

I see in the Wilson Audio manual for the Alexia V the terms "time alignment" and "time domain alignment." What is your understanding as to Wilson Audio's official definition of "time alignment"?

Dear Ron,

Since long Wilson Audio claimed time alignment to their Aspherical Group Delay technology . John Atkinson explanations in Stereophile were extremely clear since long - I remember reading about it by the time I got my X2. Little to add about the subject. Also since long reviewers and Wislon Audio focused on the "good integration of the drive-units' outputs through the crossover regions in the frequency domain."

 

[microstrip]

If it's what's on the source material, don't we all want it?

In fact a bit more sophisticated than that. Anechoic stereo, by definition is physically extremely pinpoint. When we add room reflections and the spectral manipulations carried during recording and mastering it can become subjectively more diffuse. In fact, within some limitations, audiophiles can "tailor" the soundstage according to their preference. But as you say the recording can have a strong influence on it.

If we want to know of the artist or sound engineer intentions with exactitude we have to ask him! Fortunately some sound engineers gave us their perspectives on the subject.