Полочная акустика — McIntosh XR50

The XR50 is a compact three-way bookshelf loudspeaker from McIntosh Laboratory of Binghamton, New York, developed at the company's speaker centre in that city, which includes a full-size anechoic chamber. McIntosh lists the MAC7200 stereo receiver, the MA252 integrated amplifier and the MCD350 SACD/CD player among its logical companions, and the enclosure comes in Gloss Black or Red Walnut high-gloss wood.

Key specs that matter

A single 6 inch woofer with a polypropylene cone in a cast frame handles the bass, two 2 inch inverted titanium domes cover the midrange, and a 3/4 inch titanium dome works as the super tweeter. Crossover points are 500 Hz and 8 kHz. McIntosh quotes an anechoic response of 40 Hz to 45 kHz, a nominal impedance of 8 ohms, a sensitivity of 81 dB for one watt at one metre and power handling of 300 W. The cabinet is 20.3 cm wide, 43 cm tall and 29.85 cm deep and weighs 8.9 kg net, or 11 kg when boxed.

Engineering and use context

McIntosh fits the woofer with its patented LD/HP magnetic circuit, where a pair of aluminium shorting sleeves reduces the effect of the moving voice-coil field on the permanent magnet. McIntosh credits this with more linear flux in the gap, less compression from heat and a cooler voice coil, and states ten times lower distortion than its earlier designs. The driver also has a rear vent through the magnet, an open area under the spider to prevent displacement noise, a rubber surround and a copper voice coil wound in four layers. The two midranges and the super tweeter use neodymium-iron-boron magnets, which keep the drivers small enough to be mounted close together, and the super tweeter sits between the two midranges for a symmetrical polar pattern. The second-order crossover uses low-DCR inductors and low-ESR capacitors, with self-resetting PTC fuses as protection. Inside, front-to-back and side-to-side bracing stiffens a cabinet with non-parallel walls, and a vertical port vents at the rear.

Pairing

McIntosh rates the XR50 for amplifiers from 75 W upward, and the low sensitivity figure makes that lower limit sensible. Gold-plated Solid Cinch binding posts accept the speaker cables, and Power Control jacks let a McIntosh preamplifier switch on the illuminated front logo through a 3.5 mm mini plug.

Alternatives

The McIntosh ML1 Loudspeaker Mk II is a larger stand-mount model with a 12 inch woofer in a four-way, five-driver layout, supplied with its own matching stand.