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

@mijostyn ^that^ is all well put.

a few points

flat frequency response is easily obtainable in front of speakers but if the idea is to make a loudspeaker sound good, truly flat frequency response is the wrong goal (google ’bbc dip’)

time coherence is only meaningful if delivered at the listener’s ears, which is not so easy in a domestic listening environment

phase response/inversion has rarely made a major difference in the sound in my own experience (many hifi units allow for remote switching of phase, so it can be very easy to test for oneself)

lots of the things about speakers and what makes them sound good are hard to measure, so as in many things in hifi audio, measurement based criteria are necessary but insufficient conditions for a pleasing result

@jjss49 , flat is always the best place to start. It is a reference point from which adjustments can be made to suit. You can tell me you like your bass boosted 3 dB. 3dB from where? Frequency response and group delays can be easily measured with a $300 microphone and computer program. What can not be measured is the speaker's radiation pattern but this can be determined exactly from the design of the speaker. It is important to remember that the room, the speaker and where the speaker is in the room have to be considered as a unit. Frequency response curves can change dramatically just by moving the speaker a few feet. Identical speakers will have different frequency response curve depending on where they are in the room. Even in what appears to be a symmetrical room they will measure differently. It seems that only people who have no experience measuring loudspeakers in rooms think good sound is hard to measure. Once you know what type of      soundstage you like and choose the appropriate type of speaker, assuming the speaker is well designed you optimize the system in your room by measurement. You can not get to the most accurate sound without it. You start with accuracy then tune it to sound good to you.  If you have a shrill recording and have to ability to punch in a Grundy Curve (BBC curve), wonderful. I have one on a preset if I need it.

It's harder than not so easy to have time coherence at the listener ears in a home environment unless your room is an anechoic chamber. It impossible because of reflections and the inconvenience of having two ears. 

Mijo - measure and listen, not that difficult

you missed the essential point " rest of chain "

time and phase are just part of the magic since 1977....