"magneplaner" doesn’t make it’s own drivers. Magnepan does though, for its Magneplanar loudspeakers. If one wishes to give a U.S.A. company props, getting the company and product name correct, spelling them correctly, and using an upper case letter at the beginning of each would be a good start.
Another U.S.A. company making its own planar-magnetic drivers is Eminent Technology. ETs LFT (Linear Field Transducer) driver is, unlike most Magnepan drivers, of push-pull design, with magnets on both sides of the Mylar diaphram. That Mylar is attached to a substantial metal frame, and may have its tension adjusted. The Mylar in Magnepans is glued and stapled onto the outer MDF frame, no adjustment possible. In spite of those instances of superiority, audiophiles continue to ignore the ET LFT-8b, priced ($2499/pr) surprisingly close to the Magnepan MG1.7i.