MARTINLOGAN MOTION 60XT REVIEW: REFERENCE QUALITY
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 (dynamicdriver) 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 satinblack, 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.
After initial break-in, I adjusted the speaker placement to obtain the deepest, smoothest, and most natural-sounding bass, obtaining best results with the speaker face approximately 32” from the rear wall. Regarding toe-in, the manual states that “superior stereo imaging” is achieved when the speakers are aimed toward the “primary listening position.” Loudspeakers utilizing planar magnetic drivers can sometimes be susceptible to beaming or glare, and given the tremendous output that the AMTs in the 60XT are capable of, I started by gradually increasing toe-in outward from my ears until the soundstage began to collapse, then slightly inward until I got the best compromise between tonal balance and soundstage width and depth.
A final question was whether the speakers sounded better with or without their grille covers. To that end, I listened to “Brite Nightgown” from Donald Fagen’s Morph the Cat, and noted that the differences with and without grilles were similar to those between an airbrushed photograph and its original—dynamic transitions (edges) became softer and somewhat less distinct with a slightly rounded texture with the covers installed. Preferring the naked speakers, I listened to the speakers sans grilles for the remainder of the review.
Once the break-in period had elapsed, my curiosity and interest whetted, I chose Patricia Barber’s
“Inch Worm” from Café Blue [HDCD, Premonition] for my initial close-listening test. Immediately,
I was taken aback; the broad, sharply defined soundstage extended well beyond the width of the speakers, the vocals sounded eerily lifelike, and the instrumental timbre natural, with a depth so palpable I could practically reach my hands into it. I followed that with Leon Russell’s Stop All That Jazz [CD, Shelter], a stark musical contrast to Café Blue, and perhaps one of Leon’s greatest albums.
Listening to “If I were a Carpenter,” Leon’s textured, raspy voice possessed a realism, presence, and sonic texture reminiscent of a recent, live concert performance. “Spanish Harlem,” an instrumental track, begins with bongo-like percussion deep in the left channel, sequentially adding individual percussive instruments, layered on top of one another and alternating between the right and left channels. With the 60XT, this layering was phenomenal. Transparent and deep, each percussive addition overlaid its predecessor cleanly without smothering it, with the placement of every instrument pinpointed in the soundstage.
The AMT tweeter’s fast transient response and dispersion characteristics, coupled with its precise crossover with the midrange, reminded me of an ESL, though with a tad less delicacy. Perhaps the best example of the tweeter’s transient response was “Unsquare Dance” from Dave Brubeck’s
Time Further Out [CD, Columbia/Legacy], with the 60XT capturing the crisp, near-live, stick-on-steel of Joe Morello’s drumstick rimshots as few speakers can. The simultaneous juxtaposition of Eugene Wright’s upright bass in the lowermidrange/upper-bass region was coherent and solid—producing a realistic representation of all but the deepest octaves. From top to bottom, the matching of the drivers and crossover was excellent, resulting in a very live and lifelike-sounding performance.
According to the manufacturer, the minimization of floor bounce was a design goal for the Motion Series models, with the dual 8” woofers of the 60XT vertically positioned to “fill in the 200Hz– 300Hz area.” Another benefit of the woofers’ positioning (their centerline is approximately at abdomen level when seated), combined with the rear ports, is enhanced visceral and dynamic midbass impact, belying the speaker’s frequency roll-off in the bottom octaves.
Curious how the loudspeakers handled more energetic content, I listened to Rare Earth’s Ma [CD, Motown]. The instrumental “Hum and Dance Along” absolutely rocked! On “Big John Is My Name,” the vocals were audacious, realistic, and moving, and the bass quite good though not earthshaking. Cranking up the volume, however, I suddenly became aware of how much treble energy the tweeters were able to produce.
As mentioned earlier, the owner’s manual makes no specific mention during setup of the wall behind the listener, but the air motion transformer tweeters used in the Motion 60XT are capable of producing such significant output levels that the presence of a nearby and/or undamped wall can cause reflections, making the speaker sound overly hot, and distorting its true tonal character. Choosing a better seating position or using appropriate sound-absorption material on that wall can minimize, if not alleviate, the impact of this effect.
Shifting source material, this time to classical music, I listened to Erich Kunzel and the Cincinnati Symphony’s rendition of Tchaikovsky’s 1812 Overture [CD, Telarc]. Perhaps one of the most dynamic recordings of this (or any) symphonic work, with levels ranging from the delicate ringing of a triangle to the explosive melee of artillery at the work’s conclusion, the recording is a test of any loudspeaker’s ability to reproduce extreme dynamics. During the work’s climax, the 60XT fell short of making the earth move, but it was nonetheless enjoyable.
A characteristic noted repeatedly throughout my listening, regardless of source material, was the resolution of these speakers, both in definition and amplitude, and the resultant width and depth of the soundstage it conveyed. Whatever the recording, the sense of depth—in some cases previously unnoticed even on very familiar recordings—was startlingly realistic.
A loudspeaker is a transducer, converting applied electrical energy into acoustic energy, and when it comes to evaluating a transducer, perhaps no single component can affect that conversion, and ultimately, the loudspeaker’s performance, more than the power amplifier that drives it. Loudspeakers present complex and sometimes difficult demands on amplifiers, due to many factors, such as input-impedance and crossover anomalies. To evaluate the impact the 60XT’s nominal 4-ohm input impedance on different amplifiers, I listened to it with several power amplifiers of various construction, quality, and output power.
I first replaced my reference (solid-state) Sunfire amplifier with a Bob Carver Silver Seven 700 tube amplifier (current production, not to be confused with the legacy Carver model with a similar name). While certainly not requiring the massive power (700Wpc) that this tour-de-force, four-chassis tube amplifier can produce, especially in light of the 60XT’s 94dB/2.83V/1m (91dB/1W/1m) sensitivity, the MartinLogan nonetheless responded beautifully to the amplifier’s sonic character, excellent dynamic range, and low noise floor.
The Silver Seven 700 has dedicated output taps for 8, 4, and 2-ohm loads. Given the Motion
60XT’s nominal 4-ohm input impedance, I initially connected the speakers to the amplifiers’ 4-ohm taps. Listening again to the Stone Poneys’ A Different Drum, I found Linda Ronstadt’s vocals sounding easy and lifelike. When I switched to the amplifier’s 8-ohm tap and replayed the same song, the performance seemed thin and lacking in dynamics. Repeating the sequence once more, this time with the 2-ohm taps, resulted in a dull sound and a muddy performance. I used the 4-ohm tap for the remainder of my listening session.
With the prerequisites out of the way, I began assessing the combined performance of the Silver Seven 700 amplifier and the Motion 60XT. Though the speakers already sounded exceptional driven by the Sunfire amp, it didn’t take long to hear differences in the presentation with the Silver Seven. The ESL-like delicacy of the treble that, when using the Sunfire, sometimes became slightly edgy when played loud, was softened, remaining light and delicate even at higher volumes, until the AMT tweeter output finally began to beam a bit. The bass, already well presented with the Sunfire, took on a character and depth previously unheard, with 3-D spatiality perhaps the most improved sonic characteristics I noted. Although the Sunfire amplifier had previously raised the bar for Fleetwood Mac’s “Woman of a Thousand Years” from Future Games [CD, Warner] to the highest level in my experience, the Silver Seven 700 revealed a never-before-experienced depth and dreaminess in the recording.
The manufacturer specifies that the 60XTs are “compatible with 4-, 6-, or 8-ohm rated amplifiers.” To test that claim, I replaced the Silver Seven 700 in my system with an available Kenwood KM-209 stereo power amplifier (150Wpc into 8 ohms)—a mass-market model from a few years back—using the previously described bi-wire connections. It became readily apparent that the necessary drive current for the 60XT’s 4-ohm load was not available from this amplifier, which sounded weak and flat no matter the source material. Given the speaker’s efficiency, a suitable amplifier need not be exceptionally powerful, but must be able to provide adequate drive current into lower-impedance loads, and have a slew rate fast enough to satisfy the transient-response characteristics of its AMT tweeter. If one has any concerns about an amplifier’s ability to satisfy such demands with this or any other loudspeaker, it is a good idea to arrange a demo using the amplifier in question prior to purchase.
Finally, returning to the Sunfire amplifier, I integrated my Sunfire TSEQ-10 subwoofer into the system, adjusting it to complement the 60XT’s response. On the 1812 Overture, this time with the subwoofer connected, the cannon fire left me blown away! Listening to “Flight of the Cosmic Hippo” from Bela Fleck’s album of the same name [CD, Warner Bros.], Victor Wooten’s low, low bass was amazingly matched, both tonally and in output, with Fleck’s electric banjo, sounding almost as if they were in my listening room. Rounding (or perhaps I should say, bottoming) out the already superb sound of the speakers with an appropriate subwoofer makes these speakers outstanding performers overall, regardless of cost.
The Motion 60XT does many things not only right, but magnificently, provided a suitable amplifier is used to drive them. I can’t remember when I enjoyed listening to a speaker as much as I did these. As they were designed in Lawrence, Kansas, by the same team that creates the company’s electrostatic models, it should be no surprise that the upper midrange and treble are similarly voiced to ML’s ESL models, though with slightly less finesse in the upper frequencies. Vocals are lifelike, engaging, and captivating, whether you’re listening to the silky sound of your favorite chanteuse or the gravelly voice of a screaming rock star. An added benefit of the excellent driver and crossover matching is the realistic lower-midrange/upper-bass performance, further enhanced by the woofers’ vertical location in the cabinet. The 60XT produces a broad soundstage that exceeds the width of the loudspeakers’ placement, with pinpoint imaging and amazing, three-dimensional depth, even when the source material is of average sonic quality. The twin 8” woofers produce bass extension that will satisfy all but hard-core pipe organ and electric-bass aficionados (or lovers of the 1812 Overture’s artillery fire). If these heavyweight genres of music are your thing, the addition of a subwoofer of your choice (MartinLogan offers several) can easily satisfy you, too.
To enjoy the full performance that these speakers can produce, you have to be patient; the 60XT appears to require every bit of the specified 72-hour break-in period to really sing. Nevertheless, the wait is well worthwhile, rewarding the listener with sonic performance that is nothing short of unbelievably realistic compared with other speakers in this price range, as well as more expensive models.
At the outset, my expectations for a “conventional” loudspeaker designed and produced by a manufacturer whose products have historically been electrostatic designs were undefined. After living with these speakers, however, I no longer have any doubts; the 60XTs are so impressive I could easily adopt them as my reference. Listening to the them was tantamount to a physical addiction for me! They are a “must audition” for anyone interested in natural and realistic sound that will continue to satisfy and impress for a very long time. Highly recommended.