Speaker Placement

Stereo is very different than two mono channels. You should read up on stereo microphone techniques.

While the OP is wrong in his conclusions, there is some truth in his thinking. If you position your speakers as he suggest you would minimize any crosstalk cancellation between the loudspeakers. This is something that Phase Linear/Carver did with their autocorrelator and Polk with their SDA loudspeakers.

If you want to experiment with the concept all you need to do is place absorptive material midway between your speakers and extend the material to the listening position. Your listening space is effectively bisected. Ideally the only sound that reaches your right ear is coming from the right loudspeaker with the same for the left ear/loudspeaker. I listened to a demo of this approach back in the early 90s and it did create a very convincing stereo image without the headphone like hole in the middle.

And even though I disagree with the OP what he suggests cost nothing to try. I further applaud the fact that he didn't label his idea the "Quantum Speaker Placement Theory".

Speaker placement is dictated by the room, not ones ears

When a recording engineer produces a stereo mix from the various tracks, he is attempting to simulate a performance coming from a stage. The sound reaching the ears of a listener in the audience does not come from the side, so the studio monitors are placed out in front of the engineer while he blends the tracks between the channels to simulate the way the sounds reach the ears at different times. In order to reproduce the sound the way it was mixed, it is necessary to set the speakers out in front like the studio monitors.

Placing speakers this way is second nature to us audiophiles, so it always shocks me when I see someone's speakers set up differently, for example, aimed at each other from opposite corners of the room.

I'm sorry if I misunderstood you Roscoe50 but when your reference is 60 degrees off-axis (i.e, an equilateral triangle), 160-170 degrees IS sitting almost directly behind the speakers.

In regards your response to what Manitunc is saying, the nature of stereo may be two point sources, but the nature of hearing is not. What we all (supposedly) are trying to achieve is a reasonable facsimile of the original performance using those two point sources. In my experience headphones do not do that. Although I do occasionally listen to headphones, there is no way I'm giving up my speakers (arranged in a slightly isosceles triangle) for them.

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.