MartinLogan (ML) has long been associated with the design and manufacture of electrostatic loudspeakers (ESL). And while ML considers itself “a loudspeaker ‘technology’ company and not just an ‘electrostatic’ company,” its hybrid ESL models continue to be the products that music lovers are most familiar with. Nevertheless, following the introduction of the Descent subwoofer in 2001, the company introduced the Design Series (2003)—its first non-electrostatic, full-range speakers.
The current Motion Series of non-ESL (dynamic-driver) speakers from ML encompasses some thirteen models ranging from bookshelf to floorstander, with the 60XT the premium offering. In addition to three floorstanders, the series includes the ultra-slim (less than 2" thick), SLM models, as well as dedicated center-channel and sound-bar speakers targeted at home theater.
Cosmetics and Setup
In size, the Motion 60XT is substantial, though not a monster at 48" in height and 66 pounds in weight. (The assistance of a friend would be a wise precaution during setup, especially when unpacking the loudspeakers from their shipping containers and placing them in the room.)
The flawless black cherrywood finish (the speaker is also available in piano black) of my review samples was visually stunning, their rich-grain finish work exquisite. Taking a styling cue from its ESL relatives, the satin-black, perforated-steel grille covers are magnetically attached, and flat except for a series of embossed louvers physically located over the tweeter. The black, anodized outrigger feet, provided to minimize the chance of speaker tip-over, are constructed from solid aluminum billet and come with both rubber footers and floor spikes. The richness of the speakers’ appearance is rounded out by beautiful, yet functional binding posts that will accommodate anything from bare wires to spade lugs to banana plugs.
Initially, I used the excellent and specific placement guidelines in the user’s manual to set up the 60XTs. The accompanying diagrams, with both dimensional and pictorial overviews of listening rooms and the speakers’ placement within, were most helpful. I referred to them frequently.
Compared to its other floorstanding stablemates, the 60XT and its siblings are more than just skin-deep “dimensional upgrades” (i.e., bigger boxes equipped with larger drivers). For example, though all Motion Series woofer cones (as well as midranges, in three-way models) are anodized aluminum, only the 60XT’s dual 8" woofers are constructed with extra-rigid cast-aluminum baskets, rather than the cast-polymer baskets used in lesser models.
The 6½" midrange driver, like the woofer, utilizes an anodized-aluminum cone with a cast-polymer rather than an aluminum basket. In the 60XT, the midrange is located on a virtual plane with the listener’s ears, maximizing its output and dispersion characteristics, while maintaining overall tonal balance where it bridges the gap between the woofers and the tweeter. (This is very important as many of the spatial cues present in a recording reside in the midrange.) The midrange driver’s placement, combined with the tonal balance it shares with the tweeter and woofer, greatly enhances the speaker’s overall uniformity of timbre.
ML’s Folded Motion tweeters are derived from the Oskar Heil air motion transformer (AMT) design first patented in 1972. Compared to conventional dome tweeters, AMTs typically have more extended bandwidth, faster transient response, lower distortion, and greater output capability. According to MartinLogan, a single accordion-like Folded Motion driver is equivalent in surface area to eight (ten, in the case of the Folded MotionXT version) typical 1" dome tweeters. The XT variant tweeter (used only in the 60XT and 35XT bookshelf models) has specified dispersion characteristics of 80 degrees x 30 degrees (horizontal/vertical), giving it a projection closer to that of ML electrostatic panels rather than to that of a conventional dome tweeter. The combination of the XT tweeter’s dispersion characteristics with its physical location results in excellent synergy between it and the midrange, adding life and air to the frequencies within their combined range.
Following unpacking and initial setup, I first connected the 60XTs in a single-wire configuration to the voltage output of my Sunfire 300~two power amplifier, using the speaker HF input terminals linked to the LF terminals via ML’s supplied bars. In this configuration, Linda Ronstadt’s vocals on “A Different Drum” from the Stone Poneys’ Mellow Sixties [CD, Warner] sounded forward, with excessive treble energy. When I moved the input connections from the 60XT HF terminals to its LF terminals, the excessive treble energy all but vanished, as did the forwardness of Ronstadt’s vocals. I then switched to a bi-wire configuration, connecting the Sunfire’s voltage output to the loudspeaker LF terminals and its current output to the 60XT HF terminals. The sonic differences between it and the single-wire configuration were subtle but significant; Ms. Ronstadt’s voice was better placed in the soundstage, exhibiting other incremental improvements overall.