Полочная акустика — Joseph Audio PULSAR2 Graphene

The Pulsar2 Graphene is the second generation of the Pulsar, the compact two-way that the Melville, New York company Joseph Audio first launched about ten years before its successor arrived. Jeff Joseph announced the new version in April 2019. The original Pulsar was priced at USD 7,000 per pair in 2012, and the Pulsar2 Graphene lists at about USD 8,995 per pair. In the current catalogue it is positioned above the Prism stand-mount.

Key specs that matter

Drive units comprise a tweeter taken from the Pearl3 floorstander and a long-throw woofer with a precision cast magnesium cone coated with graphene, both supplied by SEAS in Norway. They meet at 2 kHz in a parallel two-way network. Frequency response over the listening window stays within 2 dB from 42 Hz to 20 kHz. Rated impedance is 8 ohms nominal, falling to no less than 6 ohms. The enclosure measures 381 mm in height, 229 mm in width and 330 mm in depth, and the packed shipping weight is roughly 16.3 kg per unit. Two sets of patented Cardas binding posts are fitted on the back. Gloss black covers the front and top, with engineered rosewood on the sides, and a Sapele Pommele version has also been pictured by the maker.

Engineering and use context

The main change from the first Pulsar is the woofer. It keeps a cast magnesium cone, but Joseph Audio used Finite Element Analysis to rework the motor system and the suspension, and the graphene coating on the cone led to redesigned filters in the crossover. SEAS applies a graphene-based nanomaterial to its magnesium alloy cones to obtain a light, stiff and well damped diaphragm. The network follows the patented Asymmetrical Infinite Slope principle, uses steep filter slopes and selected parts, and every unit is calibrated to match the design prototype. According to the maker the driver outputs remain in phase across the crossover band, which keeps the balance consistent off axis in both planes. On the first-generation Pulsar the enclosure was MDF with side walls a little under 38 mm thick, the front baffle was bevelled, the internal wiring came from Cardas and the crossover inductors were wound with heavy-gauge wire. The box is bass reflex loaded.

Pairing

Joseph Audio says a true 8 ohm load is less critical of amplifiers and cables and suits most designs, including tube amplifiers. The twin terminal sets allow bi-wiring from one amplifier or bi-amping with separate channels for woofer and tweeter. The earlier Pulsar carried a power handling rating of 25 to 300 W.

Alternatives

The Joseph Audio Prism is the lower-priced stand-mount of the brand, a two-way with an aluminium cone woofer crossed over at 2.5 kHz.