Speaker distance

Never could understand why a person listens with their chair up against the wall. I find an equilateral triangle in the middle of the room works well. 

In which part of the rectangular room the system will be located is pertinent. In an area facing a short wall in a rectangular room, I would first consider the most practical placement of the speakers within this area that minimizes boundary interactions with the front and side walls, as this is usually a limiting factor and ultimately determines ideal listening distance. One should try to get at least 1m of distance between the tweeter and those boundaries if possible. After determining speaker placement with respect to adjacent walls, measure the distance between the tweeters. Multiply that distance by 1.2 as per Jim Smith’s observations mentioned previously, and that should give the distance from tweeter-to-ear on each side. Toe the speakers in as necessary to give the most even response (REW helps tremendously). Mark this position with painter’s tape if further tweaking is desired, but this should get one close to an ideal position.

@polkalover  

Room dimensions and the ratio of direct sound to early reflections are the critical variables here — without those, it's hard to give a definitive answer rather than a preference.

That said, some general principles apply. Sitting farther from speakers increases the ratio of reflected sound to direct sound, which in a typical rectangular room means more interaction with the rear wall and side walls — potentially muddying imaging and adding coloration depending on how live or dead the room is. 

Sitting closer to speakers that are wider apart can preserve a good stereo image while keeping you more in the direct-sound field, but only up to a point: too wide and the center image collapses and you lose coherence.

The equilateral triangle rule — speaker-to-speaker distance roughly equal to listening distance — is a reasonable starting point for most rooms and most speakers, but it's not universal. Speakers with narrow dispersion reward closer, more focused listening; wider-dispersion designs are more forgiving of room interactions.

The deeper issue is that in a rectangular room, certain distances from the front and rear walls will excite bass modes more than others. So the 'better' position often has less to do with near-field vs. far-field preference and more to do with where the room lets you sit without a bass null or boom. Tools like the Room EQ Wizard modal calculator can tell you where the nodes are before you even move a piece of furniture.

^^^ What @hilde45 said! ^^^

Speaker distance see here! 

Mike