Floorstanding loudspeakers — Kaiser Acoustics Kawero! Vivace

Kaiser Acoustics designs the Kawero! Vivace as a German three-way tower with reflex loading on both the midrange and the woofer. It is 120.5 cm tall, 33 cm wide and 49.5 cm deep, and each speaker weighs 82 kg. Its bass-midrange section and its woofer each work in their own reflex-loaded volume, and the Relevator woofer takes over from the Illuminator unit in the low bass.

Key specs that matter

The maker quotes a bandwidth of 29 Hz to 26 kHz within 1.5 dB, a tighter window than the 3 dB tolerance many brands use. Sensitivity is 88 dB at 2.83 V and 1 m. The impedance curve reaches a minimum of 3.41 ohm at 140 Hz, and Kaiser asks for at least 50 W of amplifier power. That low point falls in the upper bass, where music carries much of its energy, so the amplifier sees its hardest load in a busy part of the spectrum.

Engineering and use context

Treble is handled by a Mundorf AMT tweeter built in a customised version for Kaiser. The bass-midrange unit is a custom carbon-paper sandwich cone from the Scan-Speak Illuminator series, made in Denmark. Behind it, a rear-firing passive radiator, also a custom Illuminator unit but with an aluminium cone, gives the bass-midrange section a 4th order alignment. The lowest frequencies go to a 22 cm Scan-Speak Relevator bass driver with a hard paper cone. Kaiser describes the crossover as time and phase optimised. Its capacitors and coils are Duelund CAST Cu types, and each crossover part is individually bonded to Panzerholz to absorb energy. Wiring runs point to point throughout with no printed circuit boards. As with other Kawero! models, the enclosure is built from Panzerholz, a dense German wood-based laminate, so the mass comes largely from the cabinet material rather than from bracing added later.

Pairing

With its low impedance dip, the Vivace suits solid-state amplifiers whose rated power rises as the load drops toward 4 ohm and below, or valve amplifiers with a 4 ohm tap and generous output transformers. The stated power figure is a minimum, and headroom above it helps with the modest sensitivity in a room of around 20 m2. Because the passive radiator fires rearward, leaving space behind the cabinet is sensible. Speaker cables should be sized for current, with a low resistance over the run length.

Alternatives

The Kawero! Classic is the sibling tower in the range, rated at 92 dB with a RAAL ribbon tweeter and Audio Technology drivers in a 99 kg cabinet.