Impressed that you took the time to run a quick test. Spatial compression is a hard problem though, the most expensive sound bars are easily beat by a cheap 2.1 setup. Phones are (mostly) still mono output even though a speaker out the top and bottom (perpendicular to the viewing angle) would be a win for watching videos in landscape, probably because the improvement wouldn’t be noticeably appreciated (enough to be economically feasible, anyway).

Interesting research all the same, of course!