Brochure

Our Beryllium tweeter dome is incredibly light
and extremely rigid. It is essentially only limited
by the air compressed in the cavity behind it.
Ideally, a practically infinite volume would void
that constraint. To keep Sopra compact requires
devoting the cabinet to the bass, forcing us to
explore other options for loading the tweeter.
We developed and
patented the Infinite
Horn Loading system
(IHL). The tweeter
is lodged in a mono-
coque of injected
polyurethane for ideal
mass and damping in
a reduced space.
A small cavity conveys air from the rear of the
tweeter through a horn that extends out the back of
the cabinet. The horn is reinforced with a damping
material that gradually and delicately absorbs
the tweeter’s rear wave. Its acoustic impedance
is negligible, inhibiting resistance that would
otherwise alter the movement of the dome and
enhancing definition.
The advantage of this design is that it not only
isolates the tweeter from invasive vibrations, but
barely reduces the cabinet’s internal volume. We
could therefore retain the majority of the cabinet
for optimal bass performance from the woofers
and ideally position the tweeter, all in a reasonably-
proportioned cabinet.
The requirement for
Sopra to be compact
meant rethinking
tweeter loading
IHL Infinite Horn Loading
Getting the most out of the Beryllium tweeter
The rear wave from the Beryllium tweeter is gradually absorbed in the first chamber, which
in turn transmits to a damped horn that opens onto the rear of the loudspeaker, preventing
any feedback from obscuring the incredible definition of the Beryllium tweeter.