Sloped baffle

07-05-14: Kiddman
Yes, I do doubt your experience and you sure sound like a guy with no technical education and little technical aptitude. Anyone who is fixated on one aspect of design and thinks it guarantees something is usually one who has little technical experience or knowledge. Someone who has experience and physics and engineering in his background always knows designs never hinge on one parameter or feature.

listen, Kidboy, if you think that I have no technical education or background then you are deeply negative in that area! I had a good laugh when I read the above...
the more you write, the more you put your foot into your mouth. At this point you've swallowed your 1st foot & your 2nd foot is well on its way down. Like I wrote before, you are totally clueless on this subject matter.
Time-coherence is not a "parameter or feature" of speaker design; it's a speaker design philiosophy. The designer 1st decides if his/her speaker is going to be time-coherent or not. Based on this decision, he/she selects drivers, x-over topology & then determines to solve all the other issues in designing that speaker under the umbrella of time-coherence.
You are far from getting that this concept. I suggest that you change your moniker to 'more_than_clueless' (BTW, you are the one who started insulting various Audiogon members & I'm just returning the favour as I wont sit back & take your sh$$. you are a most unsavoury fellow who doesn't know how to debate a topic without insulting people. That's why I wrote - if you are going to uncivil, go find another place to waste your time. Other Audiogon members do have disagreements but we all try our best to remain civil).

the Vandersteen 2 are time and phase conherent.

And that surely does not make it a state of the art speaker, like it makes no speaker state of the art.

And, look at your depth of knowledge on display here to the rest of the A'gon community! Your writings repeatedly say that just because the Vandersteen 2 model sounds bad that selecting time-cohrerent as a design "parameter" will not make any speaker sound its best. Wow! diffident mentality here. The Vandy 2 is a really old model speaker & it's very possible that Vandersteen was limited by the driver technology available back then. It's only recently that he started drivers made to his spec - maybe he realized the limitations of what was available to him commercially? I know that a lot of the manuf who make very good drivers have stopped selling them to the public. I had a friend who owned a pair of Vandy 2 which I heard for a short period of time & long ago & not enough to make a judgement on their sound.
Once again, time-coherence is design philosophy & not a design parameter. have you heard any other time-coherent speaker? Or, are you basing all this on the Vandy 2 speaker?

Time coherent speakers are not easy to make esp. with cone drivers that's why you have very few manuf in this arena. Your pee-wee brain has informed you that it's because time-coherent speakers don't sound good so manuf have dropped the idea. Wow! Perhaps it could be these speaker manuf incompetence in understanding time-coherence & translating that to a product that can be sold that has prevented them from manuf a time-coherence speaker?? Nah, that possibly cannot be the case, right??

Lewinskih01,
it appears that you are going down the path of (Boothroyd-Stuart) Meridian (the UK-based company). If you were able to stuff your amps into your speaker, you'd have an active loudspeaker like Meridian's along with your DSP x-over. OK, so now your are not listening to passive x-over components; you are now listening to the sound of your DSP software which is processing your music signal & creating delays to align the sonics at your ear/destination.
when it comes to using a DSP x-over another company called Emerald Physics is also using this concept. I've listening to their CS2 & CS3 speakers quite a bit - both at shows & at a dealer's place. Somehow I never took to their sonics. It also did not help that a new revision of the DSP x-over arrived every week or every couple of weeks with the pledge that it was an improvement over the prev rev.
IMO, with DSP x-over you sonics will be heavily influenced by the software (very much akin to having an oversampled/upsampled DAC - here again, the quality of the sonics is heavily dependent on the upsampling/oversampling algorithm. You already know for yourself that there are some oversampling/upsampling DACs you like & others you do not).
I personally think that it's much easier to overcome the sonic short-comings of passive x-over components than it is of the DSP software.
At any rate this post was to cite the trade-offs (which I'm sure you already know).
I applaud your effort, which is a big one - biamping or triamping & getting all delays & phase of the music signal correctly lined up. I sincerely wish you all the best. Do keep us Audiogon members posted on your progress.

It seems premium driver (top Raal, Accuton, scanspeak, etc) can be had for relative low prices (compared to speakers that carry them).

what is your definition of "premium drivers"? Cost of the driver? Cost of a commercial speaker using this driver? The marketing hype surrounding that driver that makes you believe it must be the best?
From the little I know, some Scanspeak drivers are very good performance that would qualify for time-coherence.
Accuton drivers need not apply for time-coherence.
I don't know much about Raal.
Be careful how you choose your drivers - don't let cost be the judge - look at their freq bandwidth & where you intend to cross them over. FWIW.

Proving that even those who totally believe in time and phase correct speakers can love a non-coherent speaker, read the following.

The Tannoys are not time and phase coherent. The higher order crossover prevents phase coherency, and that they are not time correct shows in every review where there is an impulse test, such as the review that these comments by John Atkinson were in:

"In the time domain, the Tannoy's impulse response (fig.6) looks typical of a design that uses a high-order crossover. Indeed, the step response (fig.7) confirms my suspicion from the impulse response that the Churchill is not time-coherent, despite its use of a coaxial drive-unit that places the tweeter diaphragm close to the acoustic center of the woofer. The tweeter output arrives at the measuring microphone first, followed by the woofer output."

Note that guy who argues heavily for time and phase correctness, Lewinskih, previously wrote, on this forum:

" the Tannoy studio monitors sound simply superb. They sound cohesive like the sound is cut from a single piece of cloth. The concentric horn-loaded tweeter is superbly integrated with regular cone woofer. The sound is very real. I've paired it with a tube amp & this combination seems to be a winner to my ears. The dispersion pattern of the speaker is 90 degrees the way the woofer is made & because of the horn loaded tweeter. Hence these speaker care much less whether they are mounted high up or sitting on the floor. I've actually tested this when they sat on the floor - the images were all up at my seated ear level!
I've tried these speakers with my s.s amp as well & they sound very good there as well. Realistic sound, excellent imaging, extended highs"

Since he waxes poetic about a design that has never time nor phase alignment / coherency, one can only conclude that these characteristics are not the "be all, end all" that many espouse.

I'm a fan of time-and-phase coherent speakers (and a GMA owner). Just want to throw that out there...

One correction to the conversation - single-driver speakers are NOT time-and-phase coherent. They would be if the speaker operates as a perfect-piston over the entire frequency range, but this is not reality. At certain frequencies, the driver can't respond as quickly as a perfect-piston, and the phase starts to lag.

Lewinski... great post. I was impressed by the various digital analyses and corrections that the software was able to effect. Hopefully, speaker manufacturers will be able to achieve greater time and phase alignment, driver linearity and low distortion by designing better X-overs. It may be that the best solution will be an active crossover that can effect the various functionalities that were the subject of your post.

I realize that Richard Vandersteen does this on his high end speakers to some degree, but it sure would be nice if it would be more plug and play. After all, not everybody is a former NASA rocket scientist or a Steven Jobs/Bill Gates computer genius.

Thanks.