Bruce Thigpen invented his Eminent Technology LFT driver in response to the original, single-ended Magnepan planar-magnetic drivers, still found in most Magnepan models. I own a pair of Magnepan’s Tympani T-IVa, which features single-ended bass and midrange planar-magnetic drivers, with a push-pull true ribbon tweeter.
Single ended means magnets on only one side of the Mylar diaphram; as the conductive wire glued onto the Mylar moves away from the magnet, control of the movement of the Mylar decreases with distance. For that reason the more expensive Magnepans (for example the MG20) contain push-pull drivers, with magnets on both sides of the Mylar diaphram. In a push-pull design, the conductive element of the driver remains within the magnetic field at all excursion distances.
ALL Eminent Technology LFT drivers are push-pull, for lowest distortion magnetic-planar performance. The push-pull LFT-8b retails for $2499/pr, only slightly more than the single-ended Magnepan MG1.7i. I’ve compared the two; have you? In his Absolute Sound review of the LFT-8b, Robert Greene remarked on the very evident low distortion nature of the sound the 8b creates. A ridiculously-overlooked hi-fi bargain. All parts made in house, in Florida U.S.A.
