So thats basically a confirmation that were not talking about a level playing field here .
Any person with some sort of a brain should be very skeptic regarding those reviews.
"If you don't have a $200k [speaker]..."
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So thats basically a confirmation that were not talking about a level playing field here .
Any person with some sort of a brain should be very skeptic regarding those reviews.
BS and you are wrong. What Wilson claims and what they measure don’t match. They are not time aligned or time coherent. They are mechanically aligned …nothing more
John Atkinson addressed this aspect in footnotes in some of his "measurement" sections of Wilson Audio speakers in a long text. Our readers that have interest can find it easily and decide for themselves, I am not going to re-write it.
I'm not sure I completely follow, there is a relationship between mechanically aligning (drivers aligned) and time aligned, no? What am I missing, if anything?
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
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.
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.
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.
Altec 817 can be made with a first order series crossover at 500 hz, two way. But then the two driver is matched at 8ohm and 105ish db sensitivity to the woofers to keep consistency, unlike Wilson with multiple out of sync drivers.
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Kinda what i hear when listening to a lot of horns like the drivers are out of sync, but i have also heard a few where they had good sync mostly when all the drivers were all Horn loaded ..
Yes a lot of them are out of sync especially where they use hybrid designs. Most horns are bad, no doubt. Duos are a great example of a bad hybrid
Altec 817 everything is front firing, horn loaded down to 100ish hz, Same high sensitivity and 8 ohm impedance top and bottom, first order series crossover
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This is great research, Brad! Thank you.
In your view does "time-aligned" mean "time-coincident?" Or does "time-aligned" have a third (different than "time-coherent" and different than "time-coincident") meaning?
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"?
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"?
The way Daryl Wilson has explained it to me is the ability for an impulse wave to arrive precisely at the listener's ear. Much of his father's work was focused on eliminating timing differences.
Just as a gentle reminder of how precise the human ear can hear timing differences...in digital audio a trained ear can hear differences down to the single digit picosecond level based on recent tests. Academically, Julian Dunn established in his research that it definitely occurred down to single digit nanosecond level but he sadly passed at an early age and other researchers continued his work.
Audio is a bit like comedy. Timing is everything.
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.
Elliot G.
Industry Expert
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.
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I use time aligned, time coherent interchangeably…I have never used time coincident before. And I mean it in the sense of what JA did back when he reviewed the Dunlavy speakers…all drivers sounds hit your ears at the same time.
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