HEIL AMT

The Heil AMT (Air Motion Transformer), invented by Dr. Oskar Heil, is one of the most unique and legendary high‑frequency drivers ever made. Instead of pushing a cone forward like a normal speaker, the AMT uses a folded, accordion‑like diaphragm made from ultra‑light PET film with metal traces. When current flows through it, the pleats squeeze and expand, shooting air out at speeds up to five times faster than the motion of the diaphragm itself — which is why it’s called an Air Motion Transformer. The result is extremely fast transients, very low distortion, and a wonderfully open, highly detailed top end that many listeners describe as “effortless” and “electrostatic‑like.”