MartinLogan Motion 15 Bookshelf Speaker
The Motion 15 is in my listening room partly because I've wanted to hear it ever since I first saw it about a year ago, and partly because I mistakenly ordered it for our massive "Clash of the Minispeakers" test. That test was for speakers in the $250/pair to $400/pair range, but the Motion 15, while it's the same size as the other minispeakers, costs $799/pair. Clearly I couldn't pit a speaker costing twice the price against a field of budget-focused models.
Although the Motion 15 might not look much different from the <$400/pair minispeakers we tested, it is. The cabinet's sturdier, and covered in a gorgeous, real cherrywood veneer rather than fake wood plastic vinyl wrap. (It's available in gloss black or gloss white, too.) The binding posts are substantial thumbscrew types that permit a super-tight connection if you're using speaker cables tipped with spade lugs. MartinLogan's Folded Motion tweeter handles the highs; it's essentially the same Heil-type folded ribbon design we've seen on other MartinLogan Motion-series speakers and on models from GoldenEar Technology and others.
Besides that folded-ribbon tweeter, there's also a 5.5-inch aluminum-cone woofer in a ported enclosure. The speaker measures 11.4 inches high.
Although I didn't have a chance to include the Motion 15 in the listening panel tests we did for the <$400/pair minispeakers, I did have a chance to plug it into the same testing setup and perform a blind test myself using my custom-designed testing switcher. I shot it out against the Paradigm Atom Monitor and the Hsu Research HB-1 MK2.
To my ears, the Motion 15 sounds like it was designed to appeal to the tastes of audiophiles, and I mean the more purist-type audiophiles rather than just people who enjoy good audio systems. As we've heard in other speakers with folded-ribbon tweeters, the treble is silky and nearly sibilance-free. My favorite sibilance test track, "Shower the People" from James Taylor's Live at the Beacon Theatre, sounded smooth, smooth, smooth. "I like it," I wrote in my notes, and that's not something I often write after playing this track through a speaker or headphone under review.
In fact, I'd call the Motion 15 a voice speaker. I think it's best for vocal-oriented music, such as folk, light pop, etc. Here's another example: Meshell Ndegeocello's poppy, almost danceable version of Leonard Cohen's "Suzanne" sounded fantastic, with no noticeable coloration in the treble-heavy vocals and clean reproduction of the tune's insistent, high-pitched keyboard parts. Through the Motion 15, this pop tune sounded vivid, whereas through the others it sounded a tad lifeless (Atom Monitor) or a bit too zippy (HB-1 MK2). However, at the same time I noticed that the lower midrange didn't sound quite as open and spacious as it did with the Paradigm and Hsu speakers.
I'd probably prefer to use a pair of Motion 15s with a small subwoofer, and with a crossover in the mix to filter the mid- and lower bass out of the speaker. The reason why? The Motion 15 apparently uses a fairly high-Q bass tuning, intended to get the most output from its small cabinet. Possibly as a result, the bass sometimes sounded a little bloated and compressed to me. While it did handle the hard-slapping bottom-end lines in jazz/R&B bassist Jamaladeen Tacuma's "Lopsy Lu" without distorting, the bass never really sounded full and natural to me.
To me, the Motion 15 is something of a genre-specific speaker. I think it sounds best on material that makes the best use of its great folded-ribbon tweeter, and doesn't focus too much on the bottom end.
Frequency response of the Motion 15 measures 80 Hz to 20 kHz ±2.9 dB on-axis, ±2.6 dB avg 0°-30°, which is flatter than any of the minispeakers I measured, and which makes the Motion 15 one of the few dozen or so best-measuring speakers I've encountered (although I wonder if that slight dip in the midrange between 500 and 800 Hz is the cause of the sometimes not-so-open sound I heard) . Measured impedance is 2.9 ohms minimum, 4 ohms average. (That low point is at 1,920 Hz/-9° phase angle; the overall impedance is low enough that I have to caution against using the Motion 15 with cheap A/V receivers; they might shut down if you really push them.) Sensitivity from 300 Hz to 10 kHz, fortunately, is fairly high at 87.1 dB.