Time coherence - how important and what speakers?

http://sound.westhost.com/ptd.htm

"Do think this is an important issue?"
Its certainly something to strive for and can be easily attained. However, when price becomes a factor it may not be something one should get hung up on- as there are other things to the speakers performance that are also important. Ozfly says it right in the next to last sentence of the second paragraph.

"What speakers are time coherent?"
Any speaker with a sloped or staggerd baffle has the voice coils (acoustic centers) of the drivers lined up and this is time-aligned, a starting point (assuming the xover also keeps the drivers in phase--fortunately they usually don't go through the trouble of staggering their baffles and then ignoring the xover). Full-range loudspeakers are also time-aligned by default. And to a lesser extent in population, systems with the tweeter below the mid/woof but still on the same plane are also physically time-aligned. Thiel, Wilson, Dunlavy, Biro Technology, Spica, Vandersteen, Avalon acoustics (pretty sure), Audio Physic, Lowther, Full-range Electrostats, Martin-Logan above the bass driver (not sure what they do w/ xovers), Vienna acoustics (pretty sure) etc. to name a few off hand. Drivers can still be time-delayed electronically too, so the speaker may look conventional but still compensate for it.

Sure time and phase coherence are important, but these are only two aspects of many that go into how a speaker sounds. If a manufacturer achieves time/phase coherence but botches the crossover or driver integration, cabinet, etc. the result will not be pleasing. Gotta look(& listen) at the whole package, cause that's what you're ultimately hearing. I definitely hear something a little different when listening to Thiel speakers in terms of image specificity and a sense of dimension, but I don't know how much of that is due to their time/phase coherent design. Along with those mentioned above, Meadowlark is another company the adheres strongly to this design philosophy and much can be read about it on their website.

Just because a speaker system has a sloping baffle does not mean it is time aligned. There are a few manufacturers who would like for you to think there speakers are time aligned. This has been noted in Stereophile's reviews of speakers from time to time. Also, there is the phase issue which can undue the alignment regardless of the physical alignment of the drivers. Take a look at the impulse response of speakers and it gives you a pretty good picture. Sometimes the midrange is wired out of phase to the tweeter or woofer(pick your order)This effects when the sounds arrive. I have said in many posts that accuracy is not that big of an issue it seems. Electrostatic speakers have a terrible frequency response in general. Just look at some test results. But people like them. Don't take my word, look up the test results. They also have issues similiar to what was mentioned in a post above in regards to a 6db filter requiring a broader overlap of frequencies for its drivers except the electrostatic is trying to make a diaphragm work at most frequencies equally well which it won't.
We ALL like our colorations. Pick your poison. It appears that no design has a market edge on another. Each design has its camp. However, I personally believe in time and phase coherent speakers. If you have a speaker that produces overtones that are out of phase and not arriving at the same time as the fundamentals of the sound---they call that distortion---it distorts the original waveform. I still ask the question, who has heard perfection to know what a sound should be on any speaker unless you were in the studio for the original. Even then, most of the recorded music is mixed down and altered until it is some small piece of what it started out to be.
Hell, you've got a bunch of people who like Bose cubes with a sub. Who am I to say there wrong? Man, this argument will go on until the end of time. To phase or not to phase---to time align or not time align.
Richard Hardesty has his views that have developed over many years of listening along with most people who believe in time aligned, phase perfect speakers. Technically, there is a strong argument for this. It takes a lot more to design these speakers. More is put into the drivers for the very reason mentioned above. Compare Vandersteen's frequency response curve (or any other spec for that matter) with any speaker you want and they will hold their ground easily. Any time aligned and phase perfect speaker specs out very, very well.
My bottom line here is specs and design must not be the only issue for us audiophiles chasing our tails!

Far fewer speakers are really time-aligned than you might think. For example, the Wilson Sophia has a slanted baffle, but one look at the Stereophile review's impulse response tells you that it is not even close to being aligned in either time or phase! Speakers that really come close are the Dunlavys, Meadowlarks, Thiels, and Vandersteens. The impulse response is extremely easy to measure and tells you almost everything you need to know.

And yes, it is very important, it is the difference between merely a good-sounding speaker and one that sounds like real music.

Some consider time and phase coherent extremely important especially Richard Vandersteen.

But then you hear people rant and rave about the Hyperions, the Dynaudio Evidence Master and Temptation, the Krell LAT-1 all of which are not (I believe). From what I've read and heard from others, I would probably lean toward a speaker that was time and phase coherent in design.

Don't know about the Joseph's but the Meadowlark Blue Herrons selling for $9k are also time and phase coherent. Much effort appears to have been put into the the BH's, much like the Vandersteen Model 5's.

But on paper (I've not listened to either), the Vandersteen's appear to be over the top when it comes to design and detail. And they're only $1k more than the Blue Herons.

-IMO