Air Motion Transformer Principle Loudspeaker Drives
The paper describes new high- and mid-frequency loudspeaker drive units, based on the air motion transformer idea of Dr. Oskar Heil. Improvements concern geometrical layout as well as the use of new materials like capton-aluminium diaphragms and neodyme magnets. The membranes are made of very thin and especially folded diaphragms that are mounted in a strong magnetic field. They do not move air in a piston like action in a 7:7 ratio, but with a 4:7 diaphragm to air velocity transformation, thus improving transient response and dynamics of the system. Design details and measurement results are presented.
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