Patent Review: Air Motion Transformer Passive Radiator for Loudspeaker

In the August 2018 issue of Voice Coil, James Croft combined the review of two important independent patents, having in common the fact that they try to address the shortcomings of the work of Dr. Oskar Heil with his Air Motion Transformer (AMT) woofer system. Following a review of a Tymphany patent, Croft reviewed a related patent for an Air Motion Transformer Passive Radiator, invented by and awarded to Eugene Julius Christensen (Aspen, CO).

After successfully rebooting tube production in the US with the relaunch of the 300B, and introducing the stunning new 91E Integrated Amplifier, Western Electric has been busy in other areas. Charles Whitener, the entrepreneur and current president and CEO is determined to take Western Electric to a leading market position in home audio and is investing also in new speaker technologies. The first results will be visible at High End Munich 2022 with the presentation of the new 777 rAMT Midrange Driver.