Bookshelf Speakers — Martin Logan Motion MP10

The Motion MP10 is a compact multi-purpose speaker in MartinLogan's redesigned Motion series, which the Kansas company describes as its most ambitious acoustic and aesthetic development in its 40-year history. The MP10 is designed to work as a shallow bookshelf speaker, a desktop speaker or a wall-mounted surround, and its angled shape allows it to be mounted upside down so the output tilts toward the listener.

Key specs that matter

Two drivers are used, a Gen2 Obsidian Folded Motion tweeter of 26 x 36 mm with a 59.4 cm2 diaphragm, and a 140 mm (5.5 in) woven fibreglass mid/bass driver, crossed over at 2100 Hz. Response is 81 Hz to 25 kHz (+/-3 dB), sensitivity is 92 dB, impedance is 5 ohms, and MartinLogan specifies 20 W to 200 W of amplification. Tweeter dispersion is 90 x 90 degrees. The cabinet measures 356 x 203 x 127 mm including feet, height first, with a weight of 4.4 kg.

Engineering and use context

The Folded Motion tweeter uses a pleated thin-film diaphragm that moves air by squeezing its folds together, which gives a large radiating area from a small footprint. The Gen2 version has an upgraded motor structure for higher output and lower distortion. MartinLogan evaluated nearly 50 profiles before choosing the Folded Motion waveguide, which matches the tweeter's dispersion to that of the mid/bass driver and limits room reflections. The woven fibreglass cone sits in a cast polymer basket with unibody cone construction and a non-resonant asymmetrical chamber. The Stealth Bass Port, a rear-facing slot, lets the MP10 achieve bass output comparable to conventional bookshelf speakers at half the cabinet depth. Crossovers follow MartinLogan's McCracken-Vojtko approach developed through measurement, simulation and blind listening. Custom five-way binding posts are fitted, and finishes are gloss black, walnut and satin white. The Motion range carries a five-year MartinLogan warranty.

Pairing

The limited bass extension makes the MP10 a natural partner for a subwoofer, crossed over at 80 to 100 Hz, and in home cinema it works as a surround or height speaker behind larger Motion towers. AV receivers of 50 W or more drive it comfortably. On a desk it can lie flat, sit sideways or stand angled, and its shallow depth leaves room in front of a monitor. The shallow body also fits on narrow shelves where a conventional 250 mm deep bookshelf speaker would overhang.

Alternatives

MartinLogan's Motion XT B100 is the conventional two-way bookshelf model of the XT line.