IHL - Infinite Horn Loading
The requirement for Sopra to be compact meant that as much of the cabinet as possible had to be used for the bass. Our team had to explore a new system for loading the tweeter.
Getting the most out of the Beryllium tweeter
Our Beryllium tweeter features an incredibly light and extremely rigid dome. Its main limitation comes from the compression of air in the cavity behind it. To overcome this, the ideal would be to have a nearly infinite volume.
IHL system (Infinite Horn Loading)
The rear of the Beryllium tweeter is loaded via a small cavity which is connected to the exterior of the enclosure by a horn. The inside of the horn is filled with a damping material. Thus, sound waves from the rear of the tweeter are delicately and gradually absorbed. Its acoustic impedance approaches zero so that no resistance alters the movement of the dome. This pushes definition to its maximum. This system is patented.
The advantage of this set-up is that this only slightly affects the cabinet’s internal volume.
Thus, we can get the most out of the woofers to enhance bass performance while having an ideally-positioned tweeter, and all this in a reasonably-sized cabinet.
Moreover, it was our duty to isolate the tweeter from any interference from vibrations. The injected polyurethane mono-bloc tweeter frame provides the optimal mass and damping in a reduced space.
Comparison of Klippel multi-tone distortion performance between our IAL1 (red trace) and the new IHL (blue trace). A reduction of 30% is achieved between 1.5 and 4kHz.