Gershman rates the Black Swan at 88 dB/W/m with a 6 ohm nominal impedance and a frequency response from 18 Hz to 24 kHz. That sensitivity and load put no unusual strain on an amplifier, so a solid-state stereo amplifier or monoblocks of moderate power, or a capable valve design, can drive it. The bass reaching 18 Hz is the part that asks for reserves, since deep low notes at realistic levels draw current. The patented Separate Sub Alignment System places the woofer in its own enclosure on metal cones, while the upper cabinet with a 1 inch soft-dome tweeter and a 5.25 inch midrange straddles it on long double-layer extensions resting on IsoAcoustics feet. The bass box can be moved by a few centimetres to fine-tune the time alignment between the two sections, and its energy cannot travel into the upper enclosure. Both boxes use two 51 mm layers of high density board under piano lacquer, and the anniversary version adds upgraded drivers, an internal bass trap and a revised crossover. Black is standard and other colours are made to order.
How it sounds
Because the bass box is mechanically decoupled, low notes do not shake the cabinet that holds the midrange, so voices and piano keep a clean outline while organ pedals and synth bass extend deep. The adjustable alignment between the two boxes lets the drivers arrive in step at the listening seat, which helps the stage hold a stable width and depth in a large room.
The case consists of two completely separate cases, located one above the other in such a way that they smoothly merge into one. Each speaker has a low-frequency driver housing mounted on metal diffusers and an A-shaped housing suspended above it to accommodate midrange and high-frequency drivers.