soundstaging is not real. when listening to a symphony orchestra from the last row, there is no localization. it is difficult or near impossible to hear individual violinists in the string session. rather one perceives a string ensemble.
regarding resolution. there is a roundness and defocus, when listening to an instrument from a distance. there is such a thing as too much resolution.
as an example, consider a photograph of the human face. 8i am not interested in observing the warts, wrinkles, scars, etc. . i would rather see a smooth face. applying this idea to audio, a defocus control is most useful. it is not a matter of frequency response. it is purely the desire to create a roundness, smoothness and plesantness to the sound of all recordings.
thus, i view a stereo system as an instrument, not a reproducer, just as an artist interprets i want to create a pleasant structure to whatever i hear.
most stereo systems sound very unrealistic and unnatural when compared to live music, and a focus control would be most helpful to redress the discrepancy between live and reproduced music.