Speakers with the most detailed midrange? (non-ESL/planar)

Monitor Audio Studio.
Standmounts. Borrowed over the weekend. May be the most clear and revealing dynamic speaker I’ve heard. Sold in hifi shops but this is more a working tool for the studio. Easy to integrate with subs while they don’t give you much below 80 Hz. New technology from top end MA range. Good on Bjork recordings (which are not easy). You hear and see every layer of sound. Extremely fast transients (folded ribbon tweeter). Try Garrett Brennan "These knees". Probably miss warmth in voices you’re used to. Yes, you will hear every recorded sibling. And every.....everything. Rather inexpensive.

Bose 901 vI 18 31/2" drivers per pair add a couple subs and supertweeters and call it a day. lol

I think the OP is asking about detail - not necessarily the most neutral/accurate (Harbeth)
What's your amp. If its a flea powered amp - then you need an easy load such as an Avantgarde Horn - but by the same token very sensitive speakers pick up and play amp noise. Something like MAgico's need power but the amps that drive them have low noise - from that you tend to have more 'blackness' from which more details emerge (that is in-simplicita) 

@gosta 

Interesting. I have tried to like Monitor Audio. Certainly the detail is there but the lack of driver integration makes them sound so artificial. Just so obvious that you are listening to two or more drivers.

@shadorne

My ears are becoming more and more accustomed to the MA Studio. Or am I burning in the speakers? Well, I believe the first.. Listening to Charlie Musselwhite tonight "One night in America" (Telarc) and "Sanctuary" and I think the Studio’s doing a great job. His harmonica sounds just fine. Great imaging. It might be that MA eventually have succeeded here to part the very fast tweeter with two small 4" woofers in a d’appolito setting. The woofers are "free". Not screwed in the front baffle. Technique taken directly from their top model. One thing is clear. With these ribbons you hear more percussion and cymbals on some records than you possibly want. Listening nearfield at my desk at 1,20 meters. DSPeaker Anti-mode 2.0 to reduce interference from the desk (also DAC), Crossed 80hz to two JBL 310 subs, XTZ edge2 amp 300w d-class driving the Studios, no-name cables. Not a bad experience for rather low cost!