PS Audio was working on an AMT midrange, but was unhappy with the sound. At AXPONA, they will be using a Bohlender Graebener Neo10 planer magnetic driver.
There is a lot of inaccuracy bandied about when talking about ribbon transducers. A ribbon is a piece of very thin corrugated foil suspended in a magnetic field. They are not planar magnetic drivers (the AMT is a folded planar magnetic driver, and the Infinity EMITs and EMIMs were planar magnetics). And although 1930s era ribbon microphones did require matching transformers, modern ribbon drivers, i.e. as used in Apogee speakers, have a long enough ribbon that their DC resistance is near 4 ohms and does not require a transformer. I’m uncertain what Magnepan uses, but my guess is long, thin, planar magnetic drivers. (Though the new LRS may use ribbons - but if the conductor is bonded to a membrane, it isn’t a ribbon).
There is a lot of inaccuracy bandied about when talking about ribbon transducers. A ribbon is a piece of very thin corrugated foil suspended in a magnetic field. They are not planar magnetic drivers (the AMT is a folded planar magnetic driver, and the Infinity EMITs and EMIMs were planar magnetics). And although 1930s era ribbon microphones did require matching transformers, modern ribbon drivers, i.e. as used in Apogee speakers, have a long enough ribbon that their DC resistance is near 4 ohms and does not require a transformer. I’m uncertain what Magnepan uses, but my guess is long, thin, planar magnetic drivers. (Though the new LRS may use ribbons - but if the conductor is bonded to a membrane, it isn’t a ribbon).