It is with this design ideal of concentrating on driver development in both the mechanical and the material domains that the goal of a highly simplified cross-over is achieved. As with our other designs, we begin with a first order cross-over. This we believe allows us to achieve the most seamless integration of all of the drivers into a single, cohesive whole. This is in part why we have chosen to offer only the purest and simplest hook up interface of single-wire terminals. Special care has also been taken with the formulation of the alloys used in these propriety Vienna Acoustics speaker terminals to ensure the quietest connection interface between speaker and speaker wire.
At Vienna Acoustics, only the development and selection of drivers comes close to the time and effort dedicated to crossovers and their homogeneous interaction with the drivers. A crossover contains lots of components, each with its own independent and characteristic sound, which results in countless possible sound combinations. Additionally, every little part that is changed in a loudspeaker affects the whole sound dramatically.
All of our individual crossover components are of the highest quality, chosen exclusively by listening tests. As a result, our designs feature very expensive handpicked capacitors, and metal-oxyd-film resistors with less than 1% tolerance are chosen for their freedom from inductance. The differences in resolution and spaciousness between capacitors that have identical measurements and identical material, but are produced by different manufacturers, can at times be unbelievable! While our crossover components are chosen purely on the basis of their contribution to sound quality, we have identified another area of sonic variance in other designers' speakers. Even the tiniest variations in coil inductance may dramatically affect width and depth reproduction in the soundstage. We have eliminated this issue by winding our special air core inductors using a specially designed robot able to hold a tolerance of only 0.7%. The resulting improvement is decidedly worth the effort.
A further important impact on sound derives from the layout of the pc-board and the method of manufacturing the crossovers.
Regarding the filter design: We create soft sloped filters exclusively, which feature either 6 dB or 12 dB Bessel-characteristics slopes. These filters exhibit the least phase-shifting and obviously, because there are so few components per driver, exert the least influence on sound. In conducting tests of this philosophy, the most striking result we hear is, invariably, superiority in sheer musicality. Soft filters work only with unimpeachable (therefore expensive) drivers. That's a natural match for us at Vienna Acoustics, as we not only devote years to the development of a driver, but also use only the highest grade parts, so critical to the speaker.
A crossover may never be viewed as separate component of a speaker; it is part of a very complex interaction with the drivers connected to it. This can be represented graphically by the diagram of the crossover itself in connection with the alternate circuit diagram of the driver. Looking at that, it´s easy to understand why we only develop a driver and its dedicated crossover together. Our theory has reached its zenith in the WALTZ and the SCHÖNBERG series, in which a special subsonic filter in the crossover was predetermined as a fixed, computer-calculated constituent in the alternate circuit diagram of the special bass-/midrange driver. (To put it in technical terms: the computer-calculated transmission-function of the subsonic filter and desired bass result prescribed the necessary driver parameters.) This kind of outside-the-driver driver part was calculated and fixed before the moving parts of the driver were developed. The new method opens up all kinds of possibilities, especially enabling variations in the volume within the cabinet to produce the desired amount of bass. So it was possible, for example, to create deep and solid bass even out of our small-volume "flatspeakers."