More than Beryllium

Due to its incredible rigidity, Beryllium represents the ultimate material for a tweeter dome. Where soft domes turn choirs into grain, hard rock into noise, Beryllium can separate the complex harmonics with ease and keep the music clean and precise, also at high listening levels. But only if applied correctly. With the very narrow surround on our tweeter, the "soft dome" coloration is kept to a minimum. And with a moving mass of only 0.1 gram and a magnetic flux density of 2.0 Tesla, we are right at the theoretical limit. To translate these extreme specifications into extreme performance, the application needs to be optimal too. With the dedicated cross-over, movement of the dome is kept to a minimum, thereby eliminating distortion in the lower treble, often referred to as the undesired "bite". And by lavishly rounding the baffle, the uniquely flush mounted dome can unobstructed deliver its wide off-axis response, essential for an open sound.

A Metamodal Membrane

The Swedish company Oxeon invented a unique process to produce a very flat uni-directonal fiber tape. A weave made with this tape can be very flat and therefore requires less resin and weighs less compared to a traditional fiber weave. In other words, more carbon fibers can be used for the same weight. In fact, Textreme as it is called, is so stiff that the familiar edge resonance around 1-2 kHz is eliminated. This stiffness usually comes at the cost of severe resonances at higher frequencies which limits the operating range. But by optimising the thickness and stiffness, the Textreme membrane is engineered for a controlled resonant behaviour by distributing the break up modes, a metamodal membrane. These distributed modes, or resonances, are far less severe and the useable frequency range is increased. It is the perfect membrane for a midrange loudspeaker and it allows us to use a higher cross over between mid range and tweeter. The sound is resonant free and wonderfully clean, neutral and fast.

Fast and Powerful

Even the untrained eye will be able to see that this is not just another 10" woofer. It is purpose built for large deflection with minimal energy storage. In other words, it is powerful, fast and detailed. The strikingly large double magnet is mounted on a very stiff cast aluminum chassis and both magnet and chassis are designed for optimum airflow and ventilation. This minimises unwanted energy storage, just like the non-conducting vented voice coil and low damping rubber surround. The large surround and long voice coil allow a very high mechanical deflection of 22mm and a special designed spider limits the mechanical excursion when the woofer reaches the maximum deflection. The very high currents needed to bring this woofer close to its maximum require the large area of the 3” voice coil for sufficient cooling.

Internal Acoustics

Internal resonances can become audible through the speaker membranes. A myriad of counter measures has been applied in the Reference One. The baffle edge behind the mid range driver is chamfered to prevent the cavity resonance of the speaker cut out. There are two internal Helmholtz absorbers. One to absorbs the standing wave between cabinet bottom and top and the other to absorb the bass reflex port resonance. The bass reflex port inlet is located in an area where sound pressure of the remaining internal resonances is low. Not only on the inside, but also at the outside. The opening at the top prevents the excitation of the listening room resonance between the floor and ceiling. This seemingly simple measure will be of great benefit in many listening rooms because this room resonance is often not well controlled. And last but not least we chose a corner-less design for the bass port with a large area of 30% of the woofer membrane to prevent port turbulence and to have a linear output also at high signal levels.