Question about speaker angle

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.

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.

I think this is application specific. More toe-in will decrease reflections off the wall, so that should help with image placement. Less toe-in will increase reflections from the walls which makes things seem more spacious, but can also confuse your hearing.

If you have no wall reflections, then all toe-in does is change frequency response.

Ultimately, you are constrained by your environment.  Each case is individual and must involve experimenting to find the optimal balance between frequencies and soundstaging.  Away from the wall is generally better, with an unequal distance to the side walls and just enough toe in to achieve center fill and realistic soundstaging.