The Suspension (A)
The problem of getting a moving coil back to its starting position, after an electrical signal has driven it out, has challenged the minds of designer for years. Many types of acoustic and mechanical suspension systems have been developed. But they all had to be designed for mass production. And no device developed to date can match the performance of our patented magnetic suspension. AT 10 cycles per second, conventional voice coils return to their neutral position in about 1/350 of a second. Hartley speaker with magnetic suspension can return in 1 /600 of a second. With the fastest restoring force available on any speakers. Hartley speaker provide a quality of transient response only equaled by a live performance. 

The Voice Coil (B)
Again, innovative engineering and hand building make a difference. In our mid and full range speakers, our voice coil is actually two voice coils. They are physically isolated by a specially prepared compliance only 4 mm thick. The outer coil is made of copper and the inner of aluminum and the physical separation allows the inner aluminum coil to move independently at higher frequencies. Because the total coil is only one inch in diameter,  our cones can be of maximum mass. The Hartley voice coil was patented in 1964 and because of its unique dual design it’s the only voice coil that directs high and low frequency sounds to separate cone sections of the speaker.