The Insanity of Marketing Disguised as Science in Loudspeakers

haraldo

haraldo

Audioholic Warlord
Isn't the problem with time coherent speakers is that they are only time coherent in a very narrow listening spot? That said, Vandersteen seems to have a pretty good one with his most expensive speaker but who has those kind of bucks......
yes, it's my experience..... the Dunlavy's are called big headphones for that reason....
because only one person can listen at a time
 
Irvrobinson

Irvrobinson

Audioholic Spartan
Depends what you want.....
Lots of effects and something that blows you away, then the Salon's are probably for you....
If you want genuine music pleasure then Dunlavy's are better perhaps...... (that's just my subjective opinion)

Perhaps the Salon's make recordings better than what they are in real life... :D
I never thought of the Salon 2s that way, but maybe. I'm not brand-loyal or product-loyal, and I came about *this close* to choosing something other than the Revels. On the other hand, if this is what less than "genuine music pleasure" is like, well, I'll just have to admit to liking "lots of effects" a lot better. But I'm not proud; I eat Hershey's chocolate sometimes. ;)
 
Irvrobinson

Irvrobinson

Audioholic Spartan
yes, it's my experience..... the Dunlavy's are called big headphones for that reason....
because only one person can listen at a time
That is what the Legacy Focus was like too. One of the most defined sweet spots I've ever experienced.
 
MinusTheBear

MinusTheBear

Audioholic Ninja
Tragic.

If only they could produce the aesthetics of the B&W 802D with the SQ & measurements of the Dunlavy. 20 layers of beech, 10 coats of lacquer, and 4 days of polishing.:D

If only those damn Stereophile & Soundstage/RC people would review the Salk, Philharmonic, and Ascend.:D
Aren't Salk, Revel, Philharmonic and Ascend all proponents of higher order crossovers?
 
C

cschang

Audioholic Chief
The point is, what is accurate? Is it the duplicate reproduction of a sine wave, or is it what the end user actually hears, and what parameters actually dictate this? Hell, if you want to go all the way with this empirical hypocrisy, who really is your control group? Who do you hold as your norm?

The reproduction of an artist's painting would never be held to empirical verification. Science would never enter the discussion.

DJ
This all goes back to what measurements does the engineer/designer feel most important to replicate, and understanding them.

Accuracy, at a single reference point, can be determined by an FR measurement and time domain measurement. If those are replicated at the reference point (seating position) the listener will hear the same thing.
 
AcuDefTechGuy

AcuDefTechGuy

Audioholic Jedi
No...not in relation to FR, but in terms of time coherency.
So they may sound terrible when sitting horizontally off-axis, but they may still measure very smoothly on their horizontal frequency off-axis?
 
C

cschang

Audioholic Chief
So they may sound terrible when sitting horizontally off-axis, but they may still measure very smoothly on their horizontal frequency off-axis?
You have to quantify terrible.

I have not heard Dunlavys, but my understanding is that have wonderful imaging in the narrow sweet spot, but that it was lost as you moved off axis.
 
C

cschang

Audioholic Chief
Why did Dunlavy go out of business in 2002?
Dunlavy Closes Doors | Stereophile.com

And an interesting quote from one of the speaker reviews:

"DAL firmly believes that a full set of credible measurements, made by qualified engineering staff using state-of-the-art equipment and facilities, can reliably predict the potential of a loudspeaker to accurately reproduce the complex sounds of music."—Dunlavy Audio Labs

http://www.stereophile.com/floorloudspeakers/99dun4/index.html

And a review that has off-axis measurements (that don't look great for that matter):

http://www.stereophile.com/floorloudspeakers/166/index.html
 
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N

Nuance AH

Audioholic General
Isn't the problem with time coherent speakers is that they are only time coherent in a very narrow listening spot? That said, Vandersteen seems to have a pretty good one with his most expensive speaker but who has those kind of bucks......
I certainly don't, but they still remain the best speakers I've ever heard (the Model 7's). I did listen while sitting dead center in the sweet spot, though.

You have to quantify terrible.

I have not heard Dunlavys, but my understanding is that have wonderful imaging in the narrow sweet spot, but that it was lost as you moved off axis.
That's exactly how the Vandersteen's sound to me, although I didn't listen to the Model 7's off-axis; I did with the 5's, though. While they still sounded "good," the sound stage and imaging capabilities suffered. Timbre and tone didn't shift, though, which I place a higher importance on than off-axis imaging and sound stage width/depth.

Getting back to the "reference" discussion, some of us say our reference is live music and reproducing it accurately, but until the industry standardizes the recording methods that'll never be possible IMO. What we probably should be doing is using the actual recording as the reference; i.e. does your music system reproduce as the recording intended?
 
H

Hocky

Full Audioholic
You have to quantify terrible.

I have not heard Dunlavys, but my understanding is that have wonderful imaging in the narrow sweet spot, but that it was lost as you moved off axis.
That is how ML's perform. They sound fine off axis, but a lot of imaging queues are lost. When you're in the sweetspot, you really know it because you're greeted with a massive soundstage and accurate imaging. But seriously, this is a reality of all speakers - you can't possible get an optimum stereo image if you're not in the middle. If your speakers sound the same dead center as they do 3 seats over, then something is wrong.
 
GranteedEV

GranteedEV

Audioholic Ninja
I agree, but then the revel Salon2 are not correct measuring speakers, from what I understand they employ higher order x-overs that just cannot recreate a step response or a square wave, they will not even resemble what goes into a speaker.

This is a step response from a Revel Ultima Salon 2:

Looks horrible....

Compare this to a step response from Dunlavy SC-VI

99% textbook perfect....

So if we say measurements are importane we need to look into all things, also phase coherence and time distortion.... how can a speaker be well measuring if it has a 360 degree phase shift?
Of course the ideal would be no phase shift, but there's no perfect solution, so you have to weigh these things on their audibility relative to other things. In reverberant spaces phase shift is certainly less audible than in anechoic spaces. So if people "enjoy" listening in anechoic spaces I suppose they might prefer designs with less phase shift.

For those that prefer listening in typical or live acoustic spaces, phase shift becomes much less significant, arguably inaudible on the majority of actual source content. A speaker with minimum phase shift, will have other issues. The off-axis response (not only vertical but horizontal), pistonic behaviour, and power handling are all compromised.

I'll say this though, as far as driver interference patterns, as I said earlier I think I would take 360 degrees out of phase over 270 or 90 deg out of phase.

Of course, there exist speakers that avoid these phase shifts for a single microphone (btw, we have two ears though), while drawing many of the benefits of higher order crossovers. The NHT XD comes to mind; it uses DEQX circuitry to get what is akin to 110db/octave slopes, without the accompanying phase shift. Like anything using FIR filters is not a 100% perfect solution, but they're arguably a better one. But as long as the hi fi community is using passive loudspeakers, I don't see that as an option.

Don't forget, cone n dome drivers aren't free from phase shifts either. Or anything with a vent or passive radiator? Even electronics.

Ultimately there's no perfect loudspeaker that i'm aware of, but there are many that are extremely good. You have to weigh each measurement.

Does the step response really matter as much as the off-axis response? Not IMO, in ~95% of listening spaces, to ~90% of source content.

That's where auditions DO come in. You can't decide what a speaker absolute sounds like without hearing it, but you can often get a VERY good idea. Accurate speakers sound more similar than they sound different.

Marketing departments of companies (often with anechoic chambers) making so-called time coherent speakers might want you to think elsewise, but there's a lot more to sound in real rooms than a step response and a 0 degree frequency response. That doesn't mean the measurements don't matter, only that you need to weigh them correctly for their final listening place.
 
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AcuDefTechGuy

AcuDefTechGuy

Audioholic Jedi
If your speakers sound the same dead center as they do 3 seats over, then something is wrong.
What?:D

So it's good to have only 1 person get the sweet optimal sound spot, while the 10 other people hear something not optimal?

But seriously, this is a reality of all speakers - you can't possible get an optimum stereo image if you're not in the middle.
I don't sit in the middle of my room. I like to lie down on my Lounger, relax, and watch movies and listen to music. They sound fantastic whether I sit upright, stand up, lie down, sit centered or to the sides.
 
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H

Hocky

Full Audioholic
What?:D

So it's good to have only 1 person get the sweet optimal sound spot, while the 10 other people hear something not optimal?



I don't sit in the middle of my room. I like to lie down on my Lounger, relax, and watch movies and listen to music. They sound fantastic whether I sit upright, stand up, lie down, sit centered or to the sides.
That is physics. If you hear the same stereo image 6 ft off center as you do in the center, your center image is compromised. You cannot possibly hear both speakers at equal levels unless you're in the middle of them. I can sit whereever and have fantastic sound, too, but the imaging suffers.
 
GranteedEV

GranteedEV

Audioholic Ninja
That is physics. If you hear the same stereo image 6 ft off center as you do in the center, your center image is compromised. You cannot possibly hear both speakers at equal levels unless you're in the middle of them.
Technically, you can. scroll back a page or two where Irv robinson linked a white paper from pi speakers. Controlled, but-highish (but not beaming) directivity + Crossfiring will get you very close to this exact scenario of hearing both speakers at equal levels.

It won't get the timing cues 100% because that's impossible. But that doesn't mean it's not possible to bet the levels extremely close off-axis.

If I could fit a pair of 10" 90 degree crossfired coaxials into my car, i'd do it. I'm actually considering it, when CSS comes out with its new driver. Or maybe KEF's 8" coax makes more sense if I can acquire a pair. Hmm..
 
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AcuDefTechGuy

AcuDefTechGuy

Audioholic Jedi
HTML:
I can sit whereever and have fantastic sound, too, but the imaging suffers.
I suppose there are different levels of "suffering".:D:D

If the imaging subjectively "suffers", but the sound quality is subjectively "fantastic", I suppose most people can live with that.:D
 
GranteedEV

GranteedEV

Audioholic Ninja
HTML:
I suppose there are different levels of "suffering".:D:D

If the imaging subjectively "suffers", but the sound quality is subjectively "fantastic", I suppose most people can live with that.:D
I think hocky uses martin logans. Those things are really beamy at higher frequencies. So the level differences from different seating positions are that much more significant, compared to, say, your Linkwitz Orions.
 
MinusTheBear

MinusTheBear

Audioholic Ninja
Dunlavy Closes Doors | Stereophile.com

And an interesting quote from one of the speaker reviews:

"DAL firmly believes that a full set of credible measurements, made by qualified engineering staff using state-of-the-art equipment and facilities, can reliably predict the potential of a loudspeaker to accurately reproduce the complex sounds of music."—Dunlavy Audio Labs

Dunlavy Audio Laboratories SC-IV loudspeaker | Stereophile.com

And a review that has off-axis measurements (that don't look great for that matter):

Dunlavy Audio Labs SC-IV/A loudspeaker | Stereophile.com

The off-axis response is a total mess. There is no free lunch with time coherency.
 
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