Question about speaker angle

In some cases, you see that because the owner either refuses to compromise the vest look for the best sound, or they simply don’t believe the difference is worth compromising the look (WAF can come into play). Of course, they might have found that what you are questioning, is the best placement for sound. Can’t speculate which case it is, with certainty. 

I have my modestly-sized, stand-mounted Nola Boxers canted very slightly inward. I found the sound a bit sterile and small in image size when the speakers were directly pointing at my ears. The image I get with the speakers just off parallel might not be as sharply, scientifically precise as it could be but it's much more natural-sounding and spacious.

i think perhaps we are making this topic of toe-in angle harder than it needs to be

1) start with manufacturer suggestion

2) if it is a common speaker, note the suggestions of other users, perhaps

3) rotate in or out based on your preference, just do toe in/out each speaker the same degree... try varying increments

speaker maker knows the dispersion pattern of the speaker ...but doesn’t know your room, how reflective the first side bounce is, the dimensions of your listening triangle... so some common sense and experimentation and listening is need to assess what is ’goldilocks’ setting...

Not only is the dispersion pattern important, but also the distance one sits to the speaker-another thing that the designer starts with a particular assumption that might not fit one's particular setup.  High frequency energy dissipates faster than do the lower frequencies, so that if one sits farther back, the highs sound attenuated compared to close in listening.  At an audio show, I once heard a speaker built around a very expensive Voxativ driver that sounded extremely bright when I sat in what appears to be the sweet spot; but, when I went back another fifteen feet (in theory the angle actually put me more directly in line, so highs should increase), the sound became much better balanced.

The high frequency balance can be adjusted somewhat by changing the toe-in to compensate for such effects as distance from speaker, room reflections, etc.  But, to me, the biggest change one can expect is on the focus of the center image (toe-in increases focus) and the left to right spread of the image (toe-in decreases the spread), such that one is trying to find the right compromise.

There are really four basic adjustments.

1. Distance from wall behind speakers.

2. Distance of listening position from speakers (assuming this is adjustable).

3. Distance from side walls (corollary: distance between speakers).

4. Toe-in.

Whenever you make a change to 1, 2, or 3, you need to adjust 4 to keep it the same angle, but in addition if you change 1, 2, or 3, a different toe-in may prove to be optimal.