I've had a couple of recording opportunities in the last few weeks. In both cases I used a pair of Beyerdynamic M88TG mics aimed outward ala ORTF. No measurement of spacing or angles, but keeping in mind the hyper-cardioid-ness of the mics and what I've read in the Stereo Zoom article. Mics feed a Mix-Pre, the tape-out of that goes to the line-in of a PMD-660.
Session 1 was a flute/cello duo in a medium sized living room with high vaulted wood-paneled ceilings. An area rug on the wood floor under the musicians extended nearly to the mic stand. The mics were about 4 feet above the floor. I had a second 660 that I ran a pair of AT 3032 (omni) spaced about 4 feet apart, All mics were within 8 feet of the musicians. The omnis were a backup pair, I was not mixing, and the two 660s were not synchronized. I was somewhat surprised how similar the primary and the backup recordings sound. The microphones were very different. The omni pair went to an Oade Advanced Mod 660. The primary pair (hypers) went to a Basic mod 660, but I think there is not much of that mod in the line-in path. The goal here was a demo recording for the musicians.
Session 2 was four performers on a Japanese flute, two solo, one with shamisen, one with koto, and then all four flutes with bass koto. The concert performance was in a dome shaped auditorium that seats about 400, maybe 70 in the audience. The mics (M88s) were closer to the floor than session 1, more like 12 inches off the floor, aimed up slightly. The audience was very quiet. I only hear audience noise in one or two places. I've recorded here before with less directional mics and audience noise and chair creaks were more audible. This was primarily a concert performance so the mics were kept low, out of the main sight lines.
I think the results were pretty good with relatively modest equipment by professional recording standards. Session 1 required no balance tweaking. In Session 2, I gave about 3dB more to the left channel (koto side) in the Koto/flute duo. The final with all four flutes and bass koto has a bit more emphasis on the koto than is optimal, the koto was front and center. This arrangement was for the concert audience, not the recording.
I can probably get some short clips together...