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Time aligned speakers - do they make sense?

levimax

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Gotcha. Thx.

yeah, a 12" woofer mated to a 3" mid range is bad acoustic design for sure....directivity mismatch train wreck Lol
Not sure how phase fits into a discussion about basic directivity. ...???
A 12" woofer to 3" mid is less of a jump than a 1" dome to a 6" mid-woofer which is probably the number one most common 2 way bookshelf configuration. In the context of driver time alignment / blending / DSP / brick wall crossovers it is a consideration for why brick wall crossovers are not a cure all in all cases. Speaker design is hard.
 

Holmz

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Gotcha. Thx.

yeah, a 12" woofer mated to a 3" mid range is bad acoustic design for sure....directivity mismatch train wreck Lol
Not sure how phase fits into a discussion about basic directivity. ...???

Imagine that the XO slope is 6 or 12 degrees/octave… There is a gradual handover then.
 

gnarly

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A 12" woofer to 3" mid is less of a jump than a 1" dome to a 6" mid-woofer which is probably the number one most common 2 way bookshelf configuration. In the context of driver time alignment / blending / DSP / brick wall crossovers it is a consideration for why brick wall crossovers are not a cure all in all cases. Speaker design is hard.
:) Ok, i don't call a bookshelf a convincing speaker...not even close imho.
I agree most speaker design can look hard...but only because most speakers ignore basic acoustics for some specific purpose...like getting sound from a bookshelf...

and sure, DSP/blending/brick wall/high order vs low order...is all a bunch of yada yada BS, until a decent acoustic design is first in place.
Just they way i see it....

I've found, get the acoustic design right, and the complete speaker design with tuning in place is really easy...especially with todays tuning tools.
 

gnarly

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Imagine that the XO slope is 6 or 12 degrees/octave… There is a gradual handover then.
I think that is necessary if using IIR xovers, to keep a good on-axis impulse/step.
But it comes at the cost of compromising off-axis response, ie smooth directivity.

I've compared low order to high order on a bunch of different designs. Making outdoor polars on a spinorama.
I've yet to find a case where higher order didn't reduce the variation in on and off axis measurements. it simply narrows the potential muck up range. Again, this is with lin phase xovers.

But i don't work with small two-ways and such...maybe they just don't matter....dunno..
 

ernestcarl

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Good question, and one i don't know the answer to.
I'm not a fan of the multiple sub approach.
I use stereo subs closely co-located with stereo mains, such that they are within 1/4 wavelength of each other through the xover summation range.

I expect not. perfect impulse/step will occur only to a specific spot ime.
I think the goal is a reasonably defined impulse/step over as wide an area as possible.

HT is not my gig anymore. I spent about 15 years, 1990-2005, working on it and multi-channel audio. Even built large dedicated room, acoustically designed/treated, using high quality prosound boxes. Great sounding room and setup...far better than my longstanding time with electrostats and planars.
Then i made the mistake of taking the prosound speakers outdoors....broke my heart how much better outdoors sounds....no turning back for ultimate SQ.
Now, I tune DIY speakers outdoors for best quasi-anechoic I can.....and critical listening is outdoors. Truly glorious....worth the effort and wait (most of the time LOL)

I know from exchanges with Geddes, he prefers the sound of speakers and multiple subs indoors. Likes the room envelopment.
For me, it's the exact opposite. Indoors sounds like mud in comparison to outdoors...no matter how good indoors gets..
The mud vs clear distinction, only seems to grow as measurements get better and better. (maybe I have some confirmation bias going on...dunno.)

It probably has a lot to do with our underlying preference for direct vs reflected sound, and what type music we listen too...again, more dunno...

Geddes' approach and understanding is different to yours in many ways it seems -- e.g. we are insensitive to phase above 700 Hz. Though there a few common thoughts like the additional use of co-located subs with mains -- though, rather more so in a pseudo-randomly distributed mono setup and not stereo.

Yeah, he doesn't like an "outdoors" kind of listening setup -- just like Toole, he also thinks room reflections are important. However, he also says bigger rooms are "always better" -- so there's also that...

Regarding time alignment in the bass (below fs) with his multiple subs approach (more distributed low frequency sources, including mains, is "always better") it's not that important to him compared to the inherent absolute phase property of the speakers and measured steady state response in the room.

Besides, he uses large sealed main speakers (but not much forced extension) with no high-pass filter -- so phase is still relatively quite naturally linear enough overall. Not to mention his sub design uses only a first order low pass...
 

Digital_Thor

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I think that is necessary if using IIR xovers, to keep a good on-axis impulse/step.
But it comes at the cost of compromising off-axis response, ie smooth directivity.

I've compared low order to high order on a bunch of different designs. Making outdoor polars on a spinorama.
I've yet to find a case where higher order didn't reduce the variation in on and off axis measurements. it simply narrows the potential muck up range. Again, this is with lin phase xovers.

But i don't work with small two-ways and such...maybe they just don't matter....dunno..
I seems to me, that many people cross the midrange way to high, which in return compromises the directivity. I cross a 5" at 2kHz to a waveguide... because this is where it starts to beam. By doing so... I seem to have a way smoother transition between midrange and tweeter - even at LR24 filters. I measured the midrange alone... and saw that to get good dispersion, I had to cross lower than usual. Also, all the simulations are much more easy to realize, when you let the driver units work well within their limits.
 

levimax

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I seems to me, that many people cross the midrange way to high, which in return compromises the directivity. I cross a 5" at 2kHz to a waveguide
The problem with a lower mid to tweeter cross is SPL / power handling limits of the tweeter at lower frequencies. Everything is a compromise / tradeoff.
 

Digital_Thor

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The problem with a lower mid to tweeter cross is SPL / power handling limits of the tweeter at lower frequencies. Everything is a compromise / tradeoff.
More power mate ;) I have 3 x 200W in 8 ohms for my mains - active. Then 4 x 1000W in 4 ohms. for my subs ( 2 x 12" XXLS and 2 x 15" RS390HF ). Tweeter is SB26ADC, mid MW13TX and woofers are 2 x SB23NRX. Everything is closed.
Listening distance is roughly 3 m, and my room is around 50 sqm.

Remember, the most power hungry part of any system, is the bass. Just try and unplug the woofer and/or subwoofer in any system. There is so little energy up there, that it feels almost silly when you think about it.
But I agree... if it's super extreme party time... you most likely will need some kind of horn system and bigger beefier drivers.
But even one of my half deaf, horn fanatic friends, is pretty happy with my sound system. So I think that I have the SPL I need - without turning all deaf myself :D
Another fun fact.... our hearing turns down - somewhat, when listening too loud... so why listen that loud to begin with?
I aim for a well-balanced, dynamic and detailed system, which is fun to listen to, even with the volume a little lower - even though I do admit, that it's fun to play a little loud, ones in a while :cool:
 

gnarly

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Geddes' approach and understanding is different to yours in many ways it seems -- e.g. we are insensitive to phase above 700 Hz. Though there a few common thoughts like the additional use of co-located subs with mains -- though, rather more so in a pseudo-randomly distributed mono setup and not stereo.

Yeah, he doesn't like an "outdoors" kind of listening setup -- just like Toole, he also thinks room reflections are important. However, he also says bigger rooms are "always better" -- so there's also that...

Regarding time alignment in the bass (below fs) with his multiple subs approach (more distributed low frequency sources, including mains, is "always better") it's not that important to him compared to the inherent absolute phase property of the speakers and measured steady state response in the room.

Besides, he uses large sealed main speakers (but not much forced extension) with no high-pass filter -- so phase is still relatively quite naturally linear enough overall. Not to mention his sub design uses only a first order low pass...
yeah, there are certainly differences in our approaches...

My approach is rooted in the simple experience that a point source like a synergy, along with flat mag and phase , is the best sound I've heard indoors or out, (and best of best out.)
I think the point source concept needs to extend as low in frequency as possible, avoiding multiple sources when possible.

And I think there is as much need to having fully coherent sound below 1kHz, as there is above,
.....which interestingly is about where an OS waveguide quits working...if you get my drift ...;)
 

Dougey_Jones

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Vandersteen gang represent. Time and phase aligned speakers are best speakers.


Our ears evolved the precise ability to parse time and phase irregularities over thousands of years of evading large predators, don't discount the importance of this alignment in sound reproduction. Nowadays correction can be applied via DSP, but in my opinion the less DSP correction the better.
 
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levimax

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Vandersteen gang represent. Time and phase aligned speakers are best speakers.


Our ears evolved the precise ability to parse time and phase irregularities over thousands of years of evading large predators, don't discount the importance of this alignment in sound reproduction. Nowadays correction can be applied via DSP, but in my opinion the less DSP correction the better.
See below from the Vandersteen link, this is a bold claim without any proof:

We enjoy music as an emotional experience. We are drawn into good music, exhilarated by exciting music, relaxed by soothing music, and put-off by bad music. In a listening TEST, people put away their emotions and try to use their analytical mind to evaluate a speaker's performance. It's like trying to evaluate the quality of a classic painting by counting how many different colors are in it. The analytical mind focuses only on the surface, the frequency response, and ignores the reason for music; emotion.

Our opinion is that these evaluations made with the analytical mind have nothing to do with a speaker's true performance on music. They are cited in various circles as proof that time alignment doesn't matter, or that phase doesn't matter, or that all wires sound the same, or that all amps and CD players sound the same, but they all miss the fundamental truth. Listening to music is an emotional event and cannot be accurately evaluated by the analytical mind.
 

Dougey_Jones

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See below from the Vandersteen link, this is a bold claim without any proof:

We enjoy music as an emotional experience. We are drawn into good music, exhilarated by exciting music, relaxed by soothing music, and put-off by bad music. In a listening TEST, people put away their emotions and try to use their analytical mind to evaluate a speaker's performance. It's like trying to evaluate the quality of a classic painting by counting how many different colors are in it. The analytical mind focuses only on the surface, the frequency response, and ignores the reason for music; emotion.

Our opinion is that these evaluations made with the analytical mind have nothing to do with a speaker's true performance on music. They are cited in various circles as proof that time alignment doesn't matter, or that phase doesn't matter, or that all wires sound the same, or that all amps and CD players sound the same, but they all miss the fundamental truth. Listening to music is an emotional event and cannot be accurately evaluated by the analytical mind.
You posting that really doesn't move the needle in any direction at all. Denying that our hearing evolved to allow precise localization of objects based on when the waveform arrives at our ear is just silly. The perceptual differences we're discussing are obviously minute, since most people are sitting <15' from their loudspeaker and the relative incoherence of their dynamic loudspeaker drivers is small. That being said, it doesn't mean that there's nothing to it.
 

fineMen

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Please review the review of the famous Burchar 400, see https://www.audiosciencereview.com/...cal-directivity-audio-measurements-png.60213/

The central lobe (again: https://en.wikipedia.org/wiki/Acous...bination thereof) is not practically possible) is quite narrow. As the comment from the reviewer tells, better not position the ears above the main axis.

If the front baffle wasn't already slanted backwards, the ears were to be positioned below the speaker's main axis! So one could argue, that the slanted baffle only partly compensates for a difficult cross-over design and / or a whole difficult speaker design to begin with.

I suspect, that the "time alignment" for the speaker as a whole wasn't the goal with the baffle design. But only for the narrow band where woofer and tweeter meet and only because of previously made, difficult design decisions. As "time alignment" falls apart when moving in the vertical up or down the main axis just a tiny bit, such an attempt is anyway ill-advised.

I further suspect that many, if not all such designs are crippled by the same problem of a cumbersome cross-over region. It is more an indication of a bad, than for a successful speaker.

Due to the probs they may sound different, hence preferable to the all too focused audio enthusiast. A regular person might not easily warm-up to such a design. Because it presents an avoidable challenge every time it is used.
 

levimax

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You posting that really doesn't move the needle in any direction at all. Denying that our hearing evolved to allow precise localization of objects based on when the waveform arrives at our ear is just silly. The perceptual differences we're discussing are obviously minute, since most people are sitting <15' from their loudspeaker and the relative incoherence of their dynamic loudspeaker drivers is small. That being said, it doesn't mean that there's nothing to it.
My point is Vandersteen is saying listening test are invalid because of the "emotional mind" vs the "analytical mind" when listening. If we evolved to stay safe via sound localization it does not make sense that we have to be in a certain "emotional state" in order to stay safe. My main issue is the dismissal of controlled listening tests as being invalid. If controlled listening can't be used how can anyone say phase is or is not audible?
 

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fineMen

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My point is Vandersteen is saying listening test are invalid because of the "emotional mind" vs the "analytical mind" ...
Same with "energised" water. It naturally fills the thirsty pockets of the impostor with gold, hence leading to best positive feelings. Case proved.

Hate to be the bearer of bad news, but the Vandersteen Model 2 has sold more pairs ...
People wouldn't still be buying a 40 year old design if there was nothing special about it.
For one I mentioned the "special" as being different, which may discriminate the product against the competition, and if singularly so, while being o/k-ish otherwise may render it preferable. Just psychology of marketing. There are strategies that require innovation, but You have to be worse in some field to keep the balance ... they do exist, and generate success (apple - may I tell how preferable the MacOS wrapper around the underlying Linux is?).

For the other the design also exaggerates the diffuse field due to an effectively very small baffle. And may there be more.
 

Dougey_Jones

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My point is Vandersteen is saying listening test are invalid because of the "emotional mind" vs the "analytical mind" when listening. If we evolved to stay safe via sound localization it does not make sense that we have to be in a certain "emotional state" in order to stay safe. My main issue is the dismissal of controlled listening tests as being invalid. If controlled listening can't be used how can anyone say phase is or is not audible?
Richard Vandersteen's blurb that you quoted is a fairly typical sentiment in Audiophilia, I don't begrudge him that point of view. He's far from the only designer to decide that Time/Phase alignment was worth their time.

Thiel, Dunlavy, KEF (Concentric counts), Gallo and literally every manufacturer of planar or electrostatic speakers (Magnepan / Martin Logan, etc).
 

fineMen

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Richard Vandersteen's blurb that you quoted is a fairly typical sentiment in Audiophilia, I don't begrudge him that point of view. He's far from the only designer to decide that Time/Phase alignment was worth their time.

Thiel, Dunlavy, KEF (Concentric counts), Gallo and literally every manufacturer of planar or electrostatic speakers (Magnepan / Martin Logan, etc).
Nope :)

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

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.

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

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

"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.

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/

Regarding slanted baffles see my post => #76 with an example.
 
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Dougey_Jones

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Nope :)

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

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.

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

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

"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.

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 effort never delivered anything! See https://www.audiosciencereview.com/...g-klippel-andrew-jones-and-james-croft.11291/

Regarding slanted baffles see my post => #76 with an example.
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.
 
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