And while some might quibble over whether their system is "flawed," I think a better way to see the picture is that design compromises have been made and time coherence is just one of the compromises. This is especially so when one considers that the "cost" of time coherence may involve ugly sloped speakers, some of which look like insects, and drivers that are being asked to make sound over a wider pass band. Plus, speaker placement can be finicky and I don't like listening to music with my head in a vice.A few corrections, Bruce:
(1) time coherence/in-coherence in a speaker is NOT a design compromise - it's a design paradigm. Pretty much like Ralph of Atma-sphere deciding to manuf a voltage paradigm or power paradigm amplifier. Once the designer chooses the design paradigm then you can make design compromises (quality of components & other mechanical materials, etc).
(2) Drivers that are being asked to operate over a wider bandwidth in a 1st order x-over time-coherent speaker have been very carefully chosen such that these drivers have zero problems operating over that wider bandwidth. That is why most drivers on the market don't qualify. So, if the 1st order x-over time-coherent is correctly designed then the x-over frequencies will be such that these wider bandwidth capable drivers will have almost zero distortion.
(3) Speaker placement of 1st order x-over time-coherent speakers is NOT finicky & you do NOT need to put your head in a vice to listen to music. Speaker placement & listening placement have some special guidelines such as ensuring that your distance from the speakers is such that you give the sound from the various drivers to integrate & that you place you ear at the correct height off the floor. This is not unreasonable - you would do this for almost any other speaker. Yes, the sliding back/forth of the tweeter to get it correctly time-aligned to the listener's particular distance is a little bit of a trial & error thing but once again it's not unreasonable. The factory cannot set this tweeter position as different listeners listen at different distances & the distances can vary anywhere from 9'-15' depending on the speaker & room size. Once this setup is good/verified by the owner, you can shake you head like Stevie Wonder/Ray Charles or like Cerrot you can dance in your seat - sound from the 1st order x-over time-coherent will not vary....
You seem to be misguided on these few points &/or forgot that these points were discussed at length in the "Sloped Baffle" thread. Anyway, here they are again for your reading pleasure. :-) Hope that this clarifies & helps. Thanks.