Floorstanding loudspeakers — Verity Audio Sarastro IIS

The Sarastro IIS is a three-way floorstanding speaker made by Verity Audio in Quebec City. It succeeds the original Sarastro and belongs to Verity's eXR (Extended Range) line alongside the larger Lohengrin IIS, a series designed for high efficiency, wide bandwidth and high dynamic capability. Although it is a full-range design, it looks like a monitor on a matching stand, because the woofer faces the rear and no driver is visible on the lower section.

Key specs that matter

The Sarastro IIS uses Verity's own aluminium-foil ribbon tweeter, a 150mm (6-inch) midrange and a 280mm (11-inch) woofer with a 100mm (4-inch) voice-coil former. The woofer crosses to the midrange at 150Hz with a first-order (6dB/octave) slope, and a third-order filter divides the midrange and tweeter at 6.5kHz. Bandwidth is 20Hz to 60kHz, sensitivity is 93dB at 2.83V/1m and nominal impedance is 8 ohms. Amplifiers from about 7W upward can drive it. Each speaker measures 34.8 x 50.5 x 127.5cm and weighs 168kg, and it stands on a constrained-layer Floor Isolation Platform with adjustable feet.

Engineering and use context

Verity's tweeter is a true ribbon rather than a planar-magnetic unit - its diaphragm is a thin aluminium foil, suspended in a magnetic field, that also carries the signal current as the conductor. After supply problems with its earlier American source, Verity began assembling these ribbons by hand in Canada from European parts, and the same tweeter appears in the Lohengrin and Monsalvat. Because a ribbon has very low impedance, it is driven through a matching transformer, which contributes to the high sensitivity of the speaker. Audio Technology in Denmark builds the midrange and woofer to Verity's specifications. As in most Verity models, the woofer fires to the rear from a cabinet that widens toward the back, and the non-parallel sides prevent standing waves inside the enclosure. The rear bass-reflex port is machined from aluminium specially for Verity after standard ports showed noise problems. The crossover uses film capacitors made for the company by a French specialist, and the gold-plated soft-copper terminals have been a Verity fixture almost since the firm was founded.

Pairing

Thanks to its efficiency and easy load, the Sarastro IIS can be driven by low-output single-ended valve designs and equally by powerful solid-state amplifiers.

Alternatives

The Lohengrin IIS is Verity Audio's larger eXR floorstander, designed for big rooms and offering even higher sensitivity.