Speaker Placement

When a recording engineer produces a stereo mix, he is trying to produce a stereo mix. If he wants to simulate what a live audience hears then he would make a mono mix.

To be directly on axis, 160 to 170d is ideal as it is the approx angle of your ear.
The 'nature of hearing' is indeed two point as we have 2 separate ears. Listening is stereo is an attempt to make the most of this.

I prefer headphone like stereo dynamic w/o the headphones.

Abucktwoeighty-- For all practical purposes, all of our ears are indeed designed alike. Have u read up on S-Logic technology by Ultrasone hphones? They caution not to reverse( some like to hear Beatles 2 track records in reverse channels) the earpieces.

The sound live audiences hear is subject to almost infinite variables such as their seating relative to the speakers and performance source, the subsequent sound mix, ambient (reflected) sound, direct sound from the stage, and the hat size of the person in front of them.

the hat size of the person in front of them.

Folks will get a chuckle out of this but it's true.

I'll state again that our ears are not designed alike. My ears do not protrude from my head as far as some others, like Alfred E. Neuman, and others, which makes me hear a little less. As far as "practical purposes", yeah, I guess we all use them to listen with. We just don't hear the same. When I hear yellow, you may be hearing amber.

When you listen to live music the musicians are generally in front. Yes? Isn't that what the recording engineer is trying to replicate? The sound coming from in front of you?