Does Time alignment and Phase coherency make for a better loudspeaker?

Certainly it makes for better sound staging and imaging.

...however, there are varying degrees of what the industry describes, for example, as "time alignment" out there. It can sometimes strike me as more of just a marketing thing...as though either the makers think that at least half the buyers don't really understand what a proper time alignment can attain...or that half the makers don't understand it...or both maybe, IDK. 

Everybody has their own way of making and selling speakers, or choosing them FTM. But IME when you technically do this topic justice, you do get some pretty good rewards.

Eric - yes and as you no doubt aware, there are lots of other fundamental design principles at work; pistonic drivers, matching of drivers to within .25 db, testing the assembly in aneochic chamber against the reference, cabinet within a cabinat, high pass filtered midbass and up, same transfer function for main amp as sub amp, 11 bands of EQ below 120 hz for best image placement vs eliminate bass issues and live w image....the list goes on, since 1977

Not for everyone 

This is what some DIYers are saying  might affect my new dual FR design speakers,, that running a  pair of FR, one FR might be slightly nearer my listening field and thus reaches my ear BEFORE the other FR,, this a  bunch of muddled fq's. 

I say not so.

I've experiemented with this Duo design and had no issues with time/p incoherency.

 

Its all a  myth. 

Sure if you have 1 driver 1 foot behind the other,, the its possible, but all drivers at same distance, there is no such thing as 1 driver faster than the other due to one milli second slower/faster vs the other driver.... thus distortion,, its all baloney.

, matching of drivers to within .25 db ~~~~~~~~~~~~~~~~~~~~~~~~ All my drivers are completely dif sensitivity. 87, 91, 95 and about to add a 93. Sounds wonderful.

I'm afraid that while much is made of it ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Yep,