Ascendo The15 Be PRO

The15 Be PRO sits at the top of Ascendo's three tiers, and the difference from the standard PRO is one material. The diaphragm is beryllium, which has the highest stiffness-to-weight ratio of any known metal and carries sound through it roughly two and a half times faster than aluminium or titanium.

What that buys is not loudness but the absence of a specific failure. Every cone eventually stops behaving as a rigid piston and begins to flex in parts of its range — breakup — which shows up as non-linearity in the amplitude response and as energy the driver stores and releases late. Beryllium moves the first breakup so far up that it lands outside what anyone can hear.

Everything else is the 15-inch axisymmetric point source platform: a behind-screen loudspeaker for large and acoustically demanding rooms, taking front left, centre and right, or surround duty where the room is big enough to need it. The passive crossover carries the same flat wound OFC copper air core coils and silver capacitors as the rest of the PRO range.