Speaker distance

Wilson Sophia 3's -- positioned according to the 'Golden Triangle'  - an equilateral triangle between speakers and listening position. Magic.

It seems to me that the ideal distance between the speakers varies from one recording to another depending on the mix and the instrumentation. I notice with solo piano and with string quartets that no one setup satisfies every recording. So I try to find a position that works most of the time. Maybe we need moving sidewalks with remote controls that would allow us to easily place the speakers close together for say, a solo guitar and far apart for an orchestra or big band.  

I agree. My listening chair is on wheels and I can easily move a little forwards/backwards (whilst seated) to achieve the best position. 

Dedicated room: use the 1/3 methodology, 1/3 length of room for distance of speaker to back wall; 1/3 length of room for distance of chair to wall. Then I used cardas calculations for distance from side walls. Fine tune toe in.
room tuning devices applied as well as bass traps in corners 

Audiophile nearfield desktop....  about 38 inches apart.   Audience 1+1V2's. What I hear does not sound small...  Just to scale. 

Spendor sp100s, 6 feet apart, my ears around 3 feet in front, strong toe in so I can just see the inside plane of the speakers. The Spendor’s are way out in the room, with about 8 feet behind them to the back wall. REL G1 sub in the right back corner. I have been listening near field like this for the past 15 years, and it’s great. On good recordings, they disappear and project sound all around me, even behind me.