3) The CHROMIUM STYLE family’s ribbon tweeter

The classic ribbon tweeters that have been an established feature of loudspeakers for around 80 years are based on the concept of suspending the diaphragm in a fixed magnetic field, where it oscillates accordingly when alternating current passes through this field.
The aluminium strip has always been folded into a zigzag form to allow it to move and to give it a stroke capability and to extend its effective length in the air gap. Given the light moved mass involved, ribbon tweeters achieve frequencies way beyond the upper audible threshold. The fact that the diaphragm is itself electrically conductive precludes the necessity for an attached voice coil; what it does need, on the other hand, is a transformer-like coil that raises the resistance of the aluminium strip to compatible levels.
The fascinating aspect of ribbon tweeters is that the light diaphragm allows the listener to hear that they are responding rapidly and with incredibly accurate acoustic detail. This is because the upper trebles change their frequency and amplitude within thousandths of a second when reproducing music. Its ability to play an immediately active, in other words virtually inertia-free, part in this change process is the exceptional strong point of the ribbon unit.