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

A wise old uncle once told me,  "If you can't dazzle "em with brilliance, baffle  'em wth bulls__t."

...my statement refers to aiming for a perfectly flat measured speaker response as a sonic end point

But the thread is about the time domain performance of a speaker.

One cannot change that too much with DSP. The impulse response can be cleaned up somewhat. But in the edges of the crossover bands it is not really possible to do much in a passive system compared to an active one.

Once the non-time/phase aligned system and the time/phase align systems are in place, then either/both can have the frequency response dialed into what ever is asked for.

And the question then that the OP sort of asked is, "will they sound different?"

Y’all get the crappy lossy cabinet output shows up in the impulse response, and more importantly the waterfall...right ? All easy to hear.

Mijo in 1983 I was using an FFT program on a Commadore PET in the design of loudspeakers.... I feel like Lew... hackles and all

But the thread is about the time domain performance of a speaker.

One cannot change that too much with DSP. 

With my DSP controlled active speakers I can set them to linear phase or low latency the former is delayed 30ms to align the drivers the later turns off linear phase for a 3ms delay. I can't tell a difference but my room isn't an anechoic chamber. 

Ever heard any of John Fuselier’s loudspeakers from "back in the 80’s"? Time and phase aligned, with excellent coherency and pulse response. Soundstaging and imaging were exceptional. Spectral balance varied between different iterations/models, but all had an uncanny ability to sound real. If you are familiar with them, then you should know exactly what I am talking about.