Hello
@Tim Link,
I essentially agree with you.
Not only
the precision (0.1 msec level) time alignment over all the SP drivers but also
SP facing directions and
sound-deadening space behind the SPs plus behind our listening position would be critically important; I well experienced and implemented these (I designed my house/rooms for these).
Please carefully look at photo of my SP physical arrangements;
View attachment 241242
The SP cabinets and drivers are not directed to my face sitting at listening position, but they are intentionally arranged in parallel with the side walls.
Furthermore, behind the surface plane of SP drivers, we have open air space of our dining room; I believe this is critically important. Although you can see the sliding glass doors behind the main SP cabinet, the Yamaha NS-1000 cabinets are fully sealed ones with
no rear bass-reflex ports. The large heavy sub-woofers, Yamaha YST-SW1000, have open ports in front
not in rear.
I also have fairly large open space (actually another room) behind my ears as you can see in this photo;
View attachment 241243
As wrote in
my post here, the rear room is a Japanese style tatami-mattress-floor room which is acoustically well "dead" and effectively minimizes the sound reflections and resonances. Of course, the sliding doors between the rooms are kept open during the listening sessions as shown in the avobe photo.
I often place sound absorption sponge mattress in front of the white wall and the opend glass door leading to the corridor;
View attachment 241245
As shared
in my post here, I identified "that wall" causes very slight sound reflection and standing waves. Consequenly, in the occasions of my really precise "measurements", including the SP transient characteristics/behavior measurements, I put further intensive insulation/deadening treatments to the wall as shown in this photo;
View attachment 241246
As also shared
here, the ceiling of the listening room is covered by microporous diatom panels carefully selected with proper sound absorption performance. On the wooden floor, we have the large carpet also selected with suitable sound absorption properties.