Sloped baffle

Kiddman,

You are absolutely right. Solving one issue (If at all, in this case) , while creating many others is a far cry from good engineering, or good sounding loudspeakers. People who get stuck behind “critical” issues, usually do not see the entire forest. Move on, you are wasting good ink.

Bifwynne, yes, I think you have the list.
Single-driver speakers are also time coherent (since they dont have a x-over to begin with) but they might not have the freq range extension you are looking for.

Some of the latest generation Martin-Logans might also be time-coherent (they claim to have made big strides in integrating their woofer with their ESL panel) & the full-range CLX.

Quad speakers are also time-coherent such as the ESL-2085 & they might other models (ESL-989?)

Another brand is Eminent Technology LFT 8. They might have a latter rev of this model, not sure.

Yet another brand would be Sanders Sound Systems 10C & 11 ESLs. You'll find measurements of the Innersound Kaya & Eros Mk3 speakers on Stereophile if you search. Innersound speakers were basically made by the same person who owns Sanders Sound Systems today. I realize that I'm extrapolating since Innersound Kayas were time-coherent that Sanders Sound Systems 10C/11 will also be. This is based on a reasonable assumption that the same designer has not changed his philosophy when he started his new company. Atleast I did not get this impression when I spoke to him in Dec 2013/Jan 2014.

I'm almost willing to say that SoundLab ESLs are also time-coherent but I might be wrong here. Not sure.

That's all I can think of right now. If I think of more brands/models I shall post. Thanks.

Bombaywanker, 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.

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.

Usermanual and some others have it right, they recognize that this thread is only talking about one aspect of speaker design.

Just saw this thread. Wonderful to have so many knowledgeable folks chime in, plus the links to very good past discussions.

I'm certainly not up to par with my two cents here, but Psag might find it useful. Uli Brueggemann, the man behind Acourate DSP/DRC software, wrote this article on crossovers you are likely to find enlightening. It is in layman's terms: http://files.computeraudiophile.com/2013/1202/XOWhitePaper.pdf

Not sure what your system configuration is. Mine is based 100% on a computer server as source, which allows a neat approach - in my view, of course:

One way to achieve time and phase alignment is to use a multi-amped system (someone already said this above), having one amp directly driving a driver (no passive crossover used), and having a multichannel DAC and DSP software such as Acourate. Acourate allows to set digital crossovers and set time delays. So you can achieve time alignment without a sloped baffle.
Here's a great setup article http://www.computeraudiophile.com/content/556-advanced-acourate-digital-xo-time-alignment-driver-linearization-walkthrough/

I'm starting to go down this route, although I'm still coming to terms with the notion of the benefits of a time and phase aligned system where the amps are driven directly by a DAC (with the drawbacks of the latter) outdoing the benefits of my Lamm preamp driving the amp.

BTW, would like to ask a side question taking the advantage of so many knowledgeable guys reading this thread: following the above, my thoughts are of eventually replacing my speakers with DIY speakers using premium drivers, without passive XO, and enclosed in a DIY cabinet (I'm rather skilled at that). It seems premium driver (top Raal, Accuton, scanspeak, etc) can be had for relative low prices (compared to speakers that carry them). Does this sound like a good plan, or am I missing a significant issue??

Great thread!

Lewinskih01, your plan is great. There is so much info about making speakers in real texts, you will be surprised that it is not magic. First thing, yes, use the best drivers you can. Check out Audio Technology, they are some of the absolute best.

And sure, the prices are low compared to finished speakers.

Cabinets are time consuming, finishing is time consuming, this labor has to be accounted for to the tune of $100 per hour or so, all parts have to have markups, there is dealer markup. Without any gouging, prices escalate quickly.

You will learn so much in a diy endeavor, and you will end up with a good set of speakers if you research and execute well.

Start reading the DIY forum. You will find a number of folks who really know what they are talking about. Fewer "know it alls", But lots of guys who really do things.