Ribbon microphones aren't "rotationally symmetrical" because ribbons themselves aren't. There's only one physical orientation in which any ribbon microphone will have the specified pickup pattern--and even that will be in the lateral plane only.
For the Beyer M 160, the manual says to set them up so that the two red dots on the circumference of their "business end" are above one another, i.e. "pointing" up and down. Oddly I don't see any comparable note in the M 130's instruction manual.
By the way, the same thing is true with many shotgun microphones; typically you have to keep the manufacturer's logo facing directly upwards, or the pickup pattern won't be what you paid for. That's not true for all brands and types (e.g. Schoeps), but it is true for many/most.
Topic: MS Stereo Microphone Clamp for Beyerdynamic M130 & M160 — Europ (Read 3391 times)