L.O.T.S. (Loudspeaker Optimization Techniques for Soundstage)

[Duke]

I just stumbled upon his video and the best ‘magic’ placement ended up being … speakers almost half way of the room’s length … 1.1m from my LP pretty near field listening).
Even though moving the speakers back, closer to the front wall didn’t sound as good, placing them more apart ended up better. I’m curious:

1) How is the placement within the room supposed to influence the soundstage? I can understand how it’d the FR, reflections, etc.
2) Is this method much different from the classic equilateral triangle?
3) What’s the most tried and tested method of speaker/LP placement anyway?

I'll take shot at the first question, "How is the placement within the room supposed to influence the soundstage?"

Imo, in general the greater the time gap between the arrival of the direct sound and the strong onset of reflections, the better the "sense of space". A long time gap tends to disrupt the "small room signature" of the playback room, and if the late-arrival reflections are spectrally correct, they can effectively act as "carriers" for the reverberation tails on the recording, perhaps to the extent that the venue acoustic signature on the recording (whether real or engineered or both) becomes perceptually dominant. When this happens, we get a "you are there" presentation, which imo is more fun than a "they are here" presentation because there are more, and more interesting, "theres" in our music collections.

There is a spatial quality tradeoff involved, at least as far as the soundstage width goes: Fairly strong early same-side-wall reflections tend to broaden the "Apparent Source Width", resulting in sound images appearing wide to the outside of the speakers. This tends to be accompanied by some loss of image precision and soundstage depth, but my understanding is that most listeners prefer to have the wider soundstage despite the presumptive tradeoffs. (Personally I would rather forego the increased Apparent Source Width in favor of the benefits arising from minimizing the first same-side-wall reflections.)

 

[LIΟN]

I think
It's important where you put your speakers, but it's more important where I listen.
Not only in the in-room, but also in performance halls like big halls, and art halls, everything is to taste the sound according to the ratio of direct and reflective sounds.
To control it, we have to move listening point more first...

 

[CauliflowerEars]

Fairly strong early same-side-wall reflections tend to broaden the "Apparent Source Width", resulting in sound images appearing wide to the outside of the speakers. This tends to be accompanied by some loss of image precision and soundstage depth, but my understanding is that most listeners prefer to have the wider soundstage despite the presumptive tradeoffs.

Thank you, I think that is indeed what I am experiencing between the two positions I've mentioned.
1) Would treating and EQ-ing the room be able to compensate the loss of image precision to achieve both image precision and better soundstage?
2) Is there a simple way to experience how a good soundstage sounds?
Either I am doing something wrong or my (fairly) standard room is wrong, but after following the LOTS placement method, I'd say the improvement is in the range of 15%.
Nothing spectacular. Highs are certainly in the middle of the distance between the speakers, but all other frequencies seem to come from very close to either of the speaker.

Elac DBR62 <- Fosi V3 (48V) <- Topping E50 <- Wiim Mini (by optical) <- Tidal HiFi