Recently we published our first review of a product by well-known speaker manufacturer MartinLogan: the Forte wasn’t a speaker, but an amplifier with streaming capabilities. Despite our odd start, we’re back on track with a pair of MartinLogan’s Motion 15 bookshelf speakers. They’re beautiful, and they sound as good as they look.
Though MartinLogan may be best known for their ethereal electrostatic speakers, they also offer a line of speakers that use more traditional drivers. The company’s Motion series includes everything from floorstanding to bookshelf and home theater speakers, each with a mix of dynamic drivers and their Folded Motion tweeter (more on that later). We received the Motion 15 for review, which features a single 5.25-inch aluminum-cone dynamic driver and a 1” x 1.4” tweeter in a relatively small (11.4” x 6.8” x 9.5”, 12 lbs.) rear-ported MDF cabinet. The Motion 15 is available in three finishes: piano black, gloss white, and black cherrywood. Our review samples came in the latter option, with a gooey gloss maroon wood veneer that looks amazing; we only regret that our apartment doesn’t have any luxury furniture to make them look more at home.
In contrast to the rest of the cabinet, the baffle of each Motion 15 is flat black, with a small “MartinLogan” logo on the front; optional magnetic metal grilles are included. Around the back of each Motion 15 are a single set of 5-way binding posts.
MartinLogan’s Folded Motion tweeter may be the most interesting feature of the Motion series. unlike a traditional dome tweeter, the Folded Motion tweeter uses a thin, low-mass diaphragm with embedded electrical traces controlled by strong magnets, not unlike planar magnetic headphones. As current flows through the traces, the diaphragm expands and contracts like an accordion, forcing air outwards. According to MartinLogan, the folds of the Folded Motion tweeter give it far more surface area than a dome tweeter, which means that it can move more air with far less excursion, producing sound with less distortion.
The tweeters are rectangular, which means that their dispersion is far narrower than that of a circular dynamic driver — normally we’d see a narrow dispersion called a disadvantage, but MartinLogan says this helps reduce unwanted reflections on the ceiling and floor. The Motion 15’s tweeter offers 80 degrees of vertical and horizontal dispersion; the other bookshelf speaker in MartinLogan’s Motion line, the 35XT, has a slightly taller tweeter for tighter vertical dispersion and a larger woofer, giving it a bit more bass extension.
MartinLogan recommends 20-200W to drive the Motion 15; we found them plenty easy to drive with our more low-powered testing amplifiers.
After many hours of listening, we can say that the Folded Motion tweeters are the real deal — vocals and acoustic music came through extremely clear. We were also struck by how smooth the Motion 15 sound, even with tracks that we know can be sibilant in headphones and other speakers. As expected, however, the sweet spot of the Motion 15 seems a bit narrower than some other speakers we’ve tested, as their sound did audibly change when we sat too far off-axis. Also, the Motion 15’s low end did sound a little odd on some hip-hop tracks; we found things more enjoyable when we set our crossover a little higher to shift more duty to a subwoofer. If you’re a rap fanatic, these might not be the best for you. We like the Motion 15 for many other genres, though, as its smooth-but-detailed sound pairs extremely well with less-artificial genres like rock and orchestral music, where its control really shines.
When we were offered a chance to review the Motion 15, we were excited — not only because they’re a speaker from a high-end speaker manufacturer, but also because they feature an alternate, interesting technology for sound reproduction. We are, after all, tech nerds at heart.
