Gauder Akustik (formerly Isophon) is a German company that is relatively new to the U.S. high-end scene, but has been making a considerable sensation, including various glowing mentions in show reports. Gauder makes quite a few models ranging from the small Arcona 40 two-way to the large, multi-driver, floor-standing Berlina RC11. The model under review, called the Cassiano, is somewhere in the middle of the range in size and price.
The Cassianos, like all the Gauder models, use ceramic drivers. (A considerably more expensive version of the Cassianos replaces the ceramic inverted dome tweeter with a diamond tweeter.) Ceramic drivers have been around for a good while now, but it remains striking to see the pure white drivers of the Cassianos arrayed, in the particular version I had, in a pure white cabinet. Ceramic drivers are robust in use but fragile to the touch, and they are each covered here with a rigid open-wire cage to prevent damage.
The Cassianos are moderate in size—about 44" tall—but they make an emphatic if pleasant visual statement, with their white drivers and the gracefully, and one supposes functionally, curved enclosure, which is incidentally filled between its two layers with sand—shades of the Wharfedale 60s of many years ago. (In my youth I built a woofer enclosure that had a two-inch space all around its cabinet surfaces to be filled with sand—but I had to leave it behind when I graduated from college—it was too heavy to move. The Cassianos use less sand, it seems, as the speakers are of rational weight, 66 pounds each.)
Along with the super-dead cabinet and the ceramic drivers, there is another distinctive aspect of the Cassiano’s design that is not visible but is surely audible: They use extremely steep-slope crossovers. Even with pink noise, which is ultra-sensitive to such things, no lobing, no interference effect, to speak of is observable between the midrange and tweeter drivers. This sort of thing is familiar from, for example, Joseph Audio products, but it remains striking, so accustomed is one to a vertical “sweet spot” away from which most multi-driver speakers have a sort of in-and-out interference pattern. As it happens, the Cassianos also have a vertical sweet spot for another reason, but the absence of inter-driver interference effects remains a striking positive point.
The Cassianos have two 7" woofers and a midrange driver of effectively the same size combined with a 3⁄4" inverted dome tweeter. Crossover points are 180Hz and 3.2kHz. One of the potential problems of extremely steep slopes is discontinuity between drivers but in fact the Cassianos sound coherent in spite of the “50dB slopes” (this presumably means >50 dB since passive crossover slopes are necessarily whole number multiples of 6dB). The Cassianos have adjustable bass level, 0 and ±1.5 dB, as they are described. I started with + and ended with –, the + and 0 settings being audibly (and measurably) somewhat bass-heavy in my setup.
In principle, really steep slopes in a passive crossover give rise to extreme phase-angle rotation around the crossover point, but I cannot say I heard anything that I would associate with this with any certainty. Perhaps since they occur over such a narrow band, they are somehow not really observable as such.