Time coherence - how important and what speakers?

In response:

Unsound: Please allow me to expand on your comments one by one:

1. I've heard this said before regarding imaging and soundstaging. But I must tell you that as I've examined different topologies, I've found that other things such as
the dispersion characteristics, smoothness of power response, and clean decay corellate more powerfully with imaging and driver integration. Indeed, our designs are almost always singled out for praise in these areas. A very steep cutoff has real advantages because the overlap between the drivers is better controlled, so you avoid the large dips and peaks in response that upset the smoothness of the power response in slow slope crossovers. If you allow the drivers to overlap over a broad range, they may add in phase at a single point in front of the system (and this can be a very very tiny point!) but they will have sharp nulls and peaks
at different points in space. This is why such systems have trouble in three dimensional space. These interdriver cancellations actually make the transition between drivers
easier to spot, at least in my experience.

2. Which leads to my larger point. There are SO many variables in loudspeaker design, from drivers to boxes to
crossover slopes to veneers . Change any of these, and the sound changes, (okay, maybe not the veneer.) Why harp on crossover design as the focal point? It's hopelessy myopic since as you admit, the speakers within the group are all different from one another.

3. Do you seriously believe that? I suppose Dr Floyd Toole, now at Harman International, formerly at Canada's NRC, must lack the resources or talent to create low order crossover based designs because his work corellates well with ours. You can read about the Harman intl facility in Stereophile, and other places.

4. Perhaps yes!

5. I didn't say everyone voted us Best Sound. You're entitled to vote for whatever system you truly loved.
However, more seasoned audiophiles voted for us at that show
than any other system.

Your belief in low order crossovers is just that. And once you've embraced a certain mode of thought, it's difficult to
consider a different one. There's a lack of supporting evidence as to the audibility of the small degree of delay associated with steep slope designs. In fact, the research seems to indicate that it needs to be 3 times the delay that exists in high order networks before it can be barely detected.
But once you believe that you can hear, it will tend to influence your opinion of whatever speakers you listen to.
And thus the belief itself can become the overiding factor in your assesment of a given system's sound.

In response:

Karl,

It's possible for higher order crossover systems to sound "natural". This is one of the litmus tests for me when I'm working on a design. When you've created a system you must be hypercritical of it, and uncover any potential flaw in its sound before it goes out to the rest of the world. When I can sit in front of one of our creations, and forget about the balance, the crossover transitions, the boxes, and just IMMERSE myself in the music, I know we've done it. That, for me is the magic of this endeavor- it's like an audio seance!
You're bringing back some very talented ghosts. That's what I miss on most modern recordings - no ghosts. everything is
synthetic and processed with a plastic sheen to the sound.
Put on a simply miked recording of an orchestra with Heifitz
or a jazz ensemble with Miles or Pops, and the ghosts come back to life! It ain't the time domain, it's the whole reanimation that matters!

Man, I'd like to see Richard Vandersteen and Joseph Audio get in the ring! It's what makes this "Hobby" so great. My design is better than your design. I believe Vandersteen, Jim Thiel and a few others would debate his points. I've owned a lot of speakers over 40 years of this and maybe my ears are going bad but I never cared for the Joseph Audio sound. Once I was exposed to the time aligned and phase coherent systems, I will not be going back. But I guess there are so many speakers for the same reason there are so many cars---to be different.
By the way, I bought my first pair of Vandersteen's before I saw any specs,graphs or even knew what phase and timing were. They just sounded better to me. Isn't that what is important? I do listen to speakers every so often when I'm in a different city and stop in a store. I still don't like the Joseph Audio sound and I don't care how many "Shows" they win! Nice veneer though.

Josephaud, let me return the favor,
(1) The fact that you seem to have heard this before suggests that there is consistent consensus in this regard. I was not comparing these designs to yours or any other particular ones.
(2) I think we agree on some level here. It was however the impetus of this thread. I think that cabinet design is also a common consideration in these designs. We are now seeing drivers designed with these considerations as well. As such I don't think that were talking about a preoccupation with cross-overs. In my earlier post I mentioned that I was consistently attracted to speakers that shared this design principle. Considering the variety of speakers available and the limited time we have on this planet it would be foolish for me to ignore this consistent attraction.
(3) I believe that it's possible that some one with an extensive laboratory to miss opportunities for a variety of reasons. With the exception of the original PSB Alpha (considering it's very modest price point)I have yet to hear a product from this famed laboratory that I've enjoyed. Toole is not God and Canadas NRC isn't the only church.
(4) Perhaps is the operative word.
(5) You have no way of knowing just how "seasoned" an audiophile I am. I would venture to say that in the real voting world where votes are backed by real money on real purchases that the designers of "time coherent" speakers are enjoying greater sales and profits than you are. You state that I embrace a belief in low order cross overs despite the fact that in my earlier posts I mentioned that I enjoyed speakers that didn't confrom to these parameters and mentioned that it has been reported that one has claimed success with time coherence with a higher order cross over.

I don't pretend to have your expertise or the means and know how to actually tests the claims of of time coherence. I merely pointed out that I consistently find speakers making these claims most enjoyable.

Mr. Joseph wrote: "I've found that other things such as the dispersion characteristics, smoothness of power response, and clean decay corellate more powerfully with imaging and driver integration."

As an amateur speakerbuilder for about 20 years (who tried it all, even my own version of an ultra-high-slope crossover), and now as a dealer, I have to agree with Mr. Joseph's emphasis on radiation pattern and decay characteristics. I personally would trade off phase coherency in exchange for good radiation and decay characteristics.

I once built a speaker with true a first-order acoustic crossover (which is a helluva lot harder than it sounds). Yes it imaged quite well from the sweet spot, but the timbre wasn't very good. Recombining the same drivers (a Jordan module and an Audax woofer) with a higher-slope crossover at a much lower frequency sounded much better overall.

Ya'll remember the legendary Dahlquist DQ-10? Well, Jon Dahlquist found that he could either align the leading edge of the waveform, or the trailing edge, but not both. After listening tests, he chose to align the trailing edge, as he found that getting the decay right was more beneficial than getting the initial attack right.

Just for the record, I don't sell Jeff Joseph's speakers; he's a competitor. And a damn fine one at that.