Полочная акустика — Martin Logan Motion XT B100

The Motion XT B100 is the bookshelf model of MartinLogan's Motion XT series, and the company calls it its best bookshelf speaker for buyers who want maximum performance without moving to a tower. Motion XT, short for eXTreme, is the highest performance tier of the Motion family, which MartinLogan redesigned from the inside out and presented in February 2023. The four XT models are the F200 and F100 floorstanders, the B100 and the C100 centre. MartinLogan lists the B100 at USD 849.99 per speaker.

Key specs that matter

This two-way speaker uses the Gen2 Obsidian Folded Motion XT tweeter, measuring 3.2 x 6.1 cm with a diaphragm area of 79.8 cm2, over a 16.5 cm woofer with a Nomex-reinforced Kevlar cone. The crossover frequency is 2,600 Hz. Tweeter dispersion is 90 degrees horizontally and 45 degrees vertically. Frequency response is 45 Hz to 25 kHz within plus or minus 3 dB, and sensitivity is 93 dB measured at 2.83 volts and 1 m. Impedance is 4 ohm, and MartinLogan rates the speaker as compatible with amplifiers specified for 4, 6 or 8 ohm. The rear-ported cabinet measures 36.8 x 20.3 x 31.8 cm (height, width, depth, including feet, terminals and grille) and weighs 9.3 kg. Gloss Black, Walnut and Satin White are the finish options.

Engineering and use context

The XT variant is the highest-performance version of MartinLogan's Folded Motion tweeter technology, offering a 40 percent larger surface than the regular FMT, and its Gen2 upgrade brings a larger motor that raises output and cuts distortion. MartinLogan chose the waveguide profile after evaluating nearly 50 design options, aiming to align the tweeter output with the dispersion of the woofer. The Kevlar cone is described as strong and light, with properties that absorb resonance and ringing, and it is mounted in a cast aluminium basket with an asymmetrical non-resonant chamber behind it. The McCracken-Vojtko crossover, named after the brand's acoustic engineers, was designed with proprietary measurement and simulation software and tuned in double-blind listening tests. Secure-Lock grilles attach with stealth tabs and can be rotated. The custom 5-way binding posts are doubled, so the B100 can be bi-wired or bi-amplified. The base is threaded for the matching STAND25, which comes with interchangeable colour trim pieces.

Pairing

The recommended amplifier power is 20 to 250 watts. MartinLogan names 2-channel and home theater systems as uses, particularly with a subwoofer, and the C100 centre and the F100 and F200 towers complete a multichannel setup in the same finishes.

Alternatives

MartinLogan's Motion B10 is the bookshelf model of the standard Motion series, with a 14 cm woven fiberglass woofer, a 2,370 Hz crossover and 92 dB sensitivity.