Beyma's range of Air Motion Transformer (AMT) pleated diaphragm tweeters bring the highest quality audiophile sound reproduction to the world of live music. These high frequency transducers are based on AMT technology invented by German physicist and Nobel prize winner Oskar Heil. The generation of sound takes place in a very different manner from that found in ribbon tweeters or conventional compression drivers. The diaphragm is formed by longitudinal pleated folds, like the folds of an accordion. Within the straight face of each of these folds, there is a printed conductive copper thread, forming the voice coil. These diaphragms are made exclusively by Beyma, from a highly flexible material able to support extreme temperatures. The material is extremely durable, and can also be found in military and aerospace applications for the manufacture of flexible printed circuits.

The operation principle is similar to that seen in a conventional tweeter, but geometry is very different. When an alternating electrical current flows along the copper tracks of the membrane, lateral movement is created in the folds. Sound waves are generated as the air between the folds is compressed. As the displacement of each fold is very small, the air moves at great speed, producing significant sound pressure. The design can be considered an Air Motion Transformer, as it causes an air speed four times greater than that of the folds themselves -effectively creating a 4:1 ratio transformer for the movement of air. This same folded geometry also gives an effective radiation surface four times greater than that of a conventional tweeter or compression driver. As a result, AMT tweeters exhibit enormous dynamics and an exceptional transient response, vastly superior to that of any conventional tweeter, including ribbon tweeters and compression drivers.

These characteristics make the TPL-75 a highly attractive alternative to conventional compression drivers, and contributing an enormous added value to any sound system that incorporates it, equally at home in line array and point source professional sound systems or premium quality audiophile enclosures. The sonic quality, timbre, definition and clarity of this transducer are very simply unsurpassable.