I don't understand how anyone could claim a single driver BA could possibly sound better than a multi-driver BA. I suppose a person with golden ears might hear more cohesiveness with one driver but that seems kind of a moot point if all the frequencies aren't thoroughly represented.
Perhaps... although the Ortofon e-Q5, which was single driver, was rather well-liked. I guess it wasn't a traditional BA driver though, so I don't know if you'd count that. :)" On the other hand, we should keep in mind that jphonic K2 SP, with only 2 BA, arguably outperforms many other 3 driver and 4 BA driver headphones. But you were only talking about single vs multi; it was just a little side note.
I'm not an expert at this, but I think most agree that BA tends to do a better job with accuracy and timing simply because dynamic moves more air and hence often has a slower response. Manufacturers thus tend to lean more towards multi-BA than less multiple dynamic... that being said, however, Unique Melody's triple dynamic 3DD seems to have gotten an incredibly positive response here on HeadFi (and even from RinChoi). I agree that I'm kind of skeptical of models such as the 8 driver JH16, 10 driver Kaiser 10 (or haha 20 driver Sleek Audio CT20), but not having tried them myself, I'm willing to trust the positive comments other members have said. Maybe it's just a something of a placebo effect, but hey, if it works, it works. ;)