Time aligned speakers - do they make sense?

[fineMen]

Is English your second or third language? I don't mean this as an insult, I'm just having a difficult time in this thread comprehending exactly what you're talking about.

I know. No bad feelings. It is a technical topic and it seems You are not on my wavelength. Your argument regarding the "sentiment" took me one whole minute to debunk. Because of Your eloquent English.

Translated by DeepL:

The advantage of concentric aka coaxial designs is to avoid these nasty dip around the crossover area when you go off the axis.

With "planar" many myths have arisen from incoherent technical speculations. For example, the moving pattern of a plan's membrane is literally chaotic in space, meaning that the phase correlation between parts of the membrane is simply lost, also known as "breaking up," but extremely (see DML speakers). The electrostatic speaker experiences a positive feedback through mirror charges ... and many problems more.

Who is Gallo? Is there a place in technology for misleading sentiment? Is the majority right?

Not to say that all these examples didn't even deliver!

Today, "time accuracy" is only achieved to a certain extent by digital, frequency-dependent phase shift - as an aftermath. This is the only way to possibly have a "time alignment" that can be spoken of. (So that it can be measured reasonably, mind you.) The examples show only unsuccessful attempts, storytelling, no actual realizations.

So, with modern tools, it was found that all the "time alignment" wasn't worth the effort at all – again, not to mention that all the legacy stuff never delivered anything! See https://www.audiosciencereview.com/...g-klippel-andrew-jones-and-james-croft.11291/

For inclined walls see my post => #76 with an example.

 

[Dougey_Jones]

I know. No bad feelings. It is a technical topic and it seems You are not on my wavelength. Your argument regarding the "sentiment" took me one whole minute to debunk. Because of Your eloquent English.

Yep, not on your level

 

[tuga]

Hate to be the bearer of bad news, but the Vandersteen Model 2 has sold more pairs than any other audiophile speaker in history.

TAS Legacy: Vandersteen Audio Model 2 Loudspeaker - The Absolute Sound

TAS Legacy: Vandersteen Audio Model 2 Loudspeaker -

www.theabsolutesound.com

People wouldn't still be buying a 40 year old design if there was nothing special about it.

They are quite cheap / good value for money.

 

[dualazmak]

Recently, I objectively measured and established 0.1 msec precision time alignment over all the SP drivers, i.e. sub-woofers, woofers, midrange-squawkers, tweeters and super-tweeters, in my multichannel multi-driver multi-way multi-amplifier stereo setup.

If you would be interested, please visit my posts on my project thread;

- Precision measurement and adjustment of time alignment for speaker (SP) units: Part-1_ Precision pulse wave matching method: #493
- Precision measurement and adjustment of time alignment for speaker (SP) units: Part-2_ Energy peak matching method: #494
- Precision measurement and adjustment of time alignment for speaker (SP) units: Part-3_ Precision single sine wave matching method in 0.1 msec accuracy: #504, #507

As I wrote here (#520), perfect (0.1 msec precision) time alignment of all the SP drivers greatly contributes to amazing disappearance of SPs, tightness and cleanliness of the sound, and superior 3D sound stage.

Please simply PM me, if you would be interested in performing the same measurements using the test tone burst signals I prepared for the above measurements. I can also share the test tone signals prepared for the following measurements;

- Measurement of transient characteristics of Yamaha 30 cm woofer JA-3058 in sealed cabinet and Yamaha active sub-woofer YST-SW1000: #495, #497
- Identification of sound reflecting plane/wall by strong excitation of SP unit and room acoustics: #498

 

[Dougey_Jones]

Recently, I objectively measured and established 0.1 msec precision time alignment over all the SP drivers, i.e. sub-woofers, woofers, midrange-squawkers, tweeters and super-tweeters, in my multichannel multi-driver multi-way multi-amplifier stereo setup.

If you would be interested, please visit my posts in my project thread;

- Precision measurement and adjustment of time alignment for speaker (SP) units: Part-1_ Precision pulse wave matching method: #493
- Precision measurement and adjustment of time alignment for speaker (SP) units: Part-2_ Energy peak matching method: #494
- Precision measurement and adjustment of time alignment for speaker (SP) units: Part-3_ Precision single sine wave matching method in 0.1 msec accuracy: #504, #507

As I wrote here (#520), perfect (0.1 msec precision) time alignment of all the SP drivers greatly contributes to amazing disappearance of SPs, tightness and cleanliness of the sound, and superior 3D sound stage.

You don't have to convince me, I already know how much it matters. I think it's great that you can accomplish the driver time alignment in DSP nowadays, which wasn't an option at all when the most prominent time-aligned speakers were first introduced. It opens the door to *adding* this benefit to otherwise unaligned speakers, which is awesome.

On a personal note, I'm jealous of your Accuphase E-460

 

[dc655321]

The benefit of concentric aka coaxial designs is to avoid that nasty dip around the cross over region when going off-axis.

At least some coaxial designs (KEF, Genelec) are time-aligned. Hard to believe that’s serendipitous.

 

[Dougey_Jones]

Hard to believe that’s serendipitous.

It's not

 

[dualazmak]

You don't have to convince me, I already know how much it matters. I think it's great that you can accomplish the driver time alignment in DSP nowadays, which wasn't an option at all when the most prominent time-aligned speakers were first introduced. It opens the door to *adding* this benefit to otherwise unaligned speakers, which is awesome.

Yes, I fully agree!

I also believe it is critically important having reliable reproducible objective method to "measure" the time alignment (or "relative" delays) between all the SP drivers by using only the recorded room air sound; no "black-box type" procedure should be involved in the method.

It is also important that we always need to establish objective "validation" procedures plus evidences for any of the sound measurement methods (including time alignment) we would like to apply in our audio system tuning.

Accordingly, I developed/established my rather primitive but simple straightforward methods for objective time alignment tuning in my multichannel audio system.

I believe the methods I established can be easily applied in many other audio setup, if you have measurement microphone plus audio interface (ADC) and Adobe Audition (or AudaCity) for analysis. I am more than happy to share the test tone signal tracks I prepared for the time alignment measurements as well as SP transient characteristics measurements.

Actually, several people have already contacted me by PM, and I shared the test tone signals with them, just like @zergxia posted here in my thread.

 

[gnarly]

Ladies and gentlemen, don't you feel like you're going in circles?

What tell the science (no the sci-fi )?

Remember!

Linear Phase in Studio Monitors - the responses of Dr. Floyd Toole, Dr. Wolfgang Klippel, Andrew Jones, and James Croft

Imho quite a good read. https://audioxpress.com/article/zero-phase-in-studio-monitors

www.audiosciencereview.com

Haha ..Yes...the end all, be all truth....isn't it obvious?

Let us all baaaah along!

 

[pseudoid]

...best speakers.

I know at least one speaker that is bester!

Hate to be the bearer of bad news, but the Vandersteen Model 2 has sold more pairs than any other audiophile speaker in history.
People wouldn't still be buying a 40 year old design if there was nothing special about it.

Have you considered that the purchase decision could mainly be due to the fact that there really is "nothing special" about Vandie-2s?

 

[MattHooper]

With non-coincident drivers, any speaker can only be phase- or time-aligned at one particular axis, regardless of whether the alignment is done electronically or physically. This is why the vertical off-axis frequency response looks so bad. I consider a speaker to be phase-aligned on the axis where the frequency response through the crossover region is smoothest. As mentioned above, it is time-aligned when the step response is optimized. I have time-aligned speakers using electronic crossovers, and I think there is subtle, but noticeable improvement, which I notice mostly as improved imaging.

As I've mentioned before, having owned a number of Thiel's time/phase coherent speakers and many other brands, the thing that always stuck out to me about the Thiels was the precision and density of the imaging. Whenever I used other speakers, all of which seemed on their own to image very well, switching back to the Thiels was a bit like re-focusing a slightly out of focus image. The Thiels just locked things in and tended to make other speakers sound a little vague and "swimmy" in comparison.

 

[Dougey_Jones]

I know at least one speaker that is bester!

Have you considered that the purchase decision could mainly be due to the fact that there really is "nothing special" about Vandie-2s?

Have you listened to 2CE’s?

Are you actually exposing yourself as a clown right now?

 

[dc655321]

Have you listened to 2CE’s?

Are you actually exposing yourself as a clown right now?

No skin in this game, but objectively they’re a solid “meh”. At best.

 

[Dougey_Jones]

No skin in this game, but objectively they’re a solid “meh”. At best.

From the review you linked, what about +/- 5db are you taking issue with?

 

[fineMen]

Yep, not on your level

So, this got into an argument on an audiophile level, personal accuses off topic included.

You mess up driver alignment for proper frequency response (but only on axis), with speakerbox versus speakerbox alignment in a X.1 setup, with zero group delay for a whole single speaker box.

You already gave irrelevant, other gave incorrect "hints" on what to expect from whimsical designs. Sentiment was mentioned as a trustworthy attitude, and emotions were pulled to the forefront.

I'm not a twit.

 

[dualazmak]

Looks many people here would be interested in not only "time alignment" but also "Fq response".

Just for your reference, therefore, present best tuned (for my ears and brain) Fq response at listening position of my perfectly (0.1 msec precision) time-aligned (see my above posts #86 and #90) multichannel multi-driver multi-way multi-amplifier (5-way 10-channel) stereo audio system:

The slightly upward Fq response above ca. 6 kHz is intending to compensate a faint age-dependent hearing decline. Please visit my posts here and here for interesting discussion on the flexible adjustment of the "upward slope" in the high Fq zone.

Sorry to be a little bit out of the scope of this thread.

 

[gnarly]

The benefit of concentric aka coaxial designs is to avoid that nasty dip around the cross over region when going off-axis.

Hmmm...guess what causes that nasty dip in non-coaxial designs....?
It's the varying time alignments, phase summations/cancellations, reaching the ear/mic.......from separated drivers in non-coaxial designs coproducing the xover freq range

With "planar" many myths have sprouted from incoherent technical speculation. For instance the moving pattern of a planar's membrane is literally chaotic in space, means phase correlation between parts of the membrane is just lost, aka "break up", but to the extreme (see DML speaker).. An electrostatic experiences positive feedback due to mirror charges ... many more.

Well, many many measurements of commercial electrostats, planars, and ribbons, ....both at the speaker level and at tha driver level...........certainly dispute that idea.
Where did you get that "chaotic" idea? Thought i'd heard every ESL myth out there ...

"Time accuracy" is achieved only today to some degree by digital, frequency dependent phase shifting--as an aftermath. This is the only way to possibly have some "time alignment" to speak of. (So that it can be measured reasonably, mind You.) Your examples only show unsuccessful attempts, story telling, no actual realisations.

No, time accuracy is primarily a function of good acoustic design...and has been for 100 years. Before out FFT analyzers, what was the most revealing measurement technique for evaluating speakers? Square waves..... which display both magnitude and phase (collectively termed frequency response).

Why have low -order IIR xovers been overwhelming preferred historically? It's because they warp the phase relationship between frequencies the least.
Why have drivers with wide frequency overlap been used as much as possible? They are more time and phase accurate? It's because the have less phase rolloff to try to blend together through xover.

Time accuracy has always been a goal of excellent design.
It's just a little easier today.

Oh, btw digital frequency dependent phase shifting --as an aftermath is not good design, ime/imo.
Folks who have tried it and been disappointed (as they should be), appear to be the main sources of myths about linear phase.

So, with modern tools is was found that all the "time alignment" wasn't worth the effort in the first place--again not to forget that all the legacy stuff never delivered anything! See https://www.audiosciencereview.com/...g-klippel-andrew-jones-and-james-croft.11291/

One man pulls some respected folks comments, in a way to support his predisposition.....imho.
There are many respected folks with differing conclusions...(and perhaps with their own opposite biases.)

Personally, i feel getting an acoustic design and adding the electrical processing needed to make a speaker that has flat magnitude and phase.......is hard work, and takes effort. (which are the requirements for "time alignment")
It's hard work for just on-axis, and certainly hard work for off-axis too.
Most will find excuses to keep from having to go there.....

 

[dc655321]

From the review you linked, what about +/- 5db are you taking issue with?

The mid scoop, the elevating upper registers, the awful vertical directivity, the 82 dB/2.83V sensitivity. But step response looks good, so there’s that. I’m

As I said, “meh”. I’m sure it was all that 25 yrs ago.

 

[fineMen]

... (which are the requirements for "time alignment") ...

This dispute became unexpectedly rude in tone and content. By "content" I mean the lack of focus typical of an "audiophile" uninformed forum. Mixed with tons of hearsay, mostly from advertising and the supporting xx-mags, online and printed, seasoned by a complete ignorance of math and physics, stirs into a poisonous witch brew.

So, what is "time alignment" actually? What is this all about except wanting to be right? Why is it, that a 'scientific' forum seems to even more attract the cream of the bunch?

Three independent, highly regarded and successful speaker specialists from within and from the side of the industry, a professor of acoustics included, already closed the case. Nothing to be gained here, me thinks. 'Looked into the void for long enough now.

Here is it, done:

Linear Phase in Studio Monitors - the responses of Dr. Floyd Toole, Dr. Wolfgang Klippel, Andrew Jones, and James Croft

Imho quite a good read. https://audioxpress.com/article/zero-phase-in-studio-monitors

www.audiosciencereview.com

 

[gnarly]

This dispute became unexpectedly rude in tone and content. By "content" I mean the lack of focus typical of an "audiophile" uninformed forum. Mixed with tons of hearsay, mostly from advertising and the supporting xx-mags, online and printed, seasoned by a complete ignorance of math and physics, stirs into a poisonous witch brew.

Sorry if i came off rude...

I simply get sick of all the uniformed "audiophile type" BS....
But i get more sick of the "we are informed" "science type BS", that gets parroted just as much as audiophile crap.


Just cause research or an opinion came from a professor, or an "industry expert" doesn't make it good science.
And often, even if it was perfectly good science originally (for the limited claims made by the original researchers), it amazes me how folks find ways to extrapolate the original work to prove their particular totally inapplicable points.

So, what is "time alignment" actually? What is this all about except wanting to be right? Why is it, that a 'scientific' forum seems to even more attract the cream of the bunch?

Perfect time alignment is simply.....flat frequency response (magnitude) and flat phase response. That simple.
Which also equals perfect impulse, perfect step, yada yada.

If that's achieved both on and off axis, you get a perfect speaker (to the limits of its frequency response extension and SPL)

Who doesn't want that from a speaker?
It's becoming ever more possible ime. Even as some folks say we don't need it!