Reviews of Attainable Hi-Fi & Home-Theater Equipment

Reviews of Attainable Hi-Fi & Home-Theater Equipment

Note: Measurements taken in the anechoic chamber at Canada's National Research Council can be found through this link.

Definitive Technology ST-LReviewers' ChoiceNot long ago, Definitive Technology made some big splashes -- first with the introduction of their Mythos ST SuperTower loudspeaker, and then of the smaller Mythos STS. These speakers combined high-tech drivers and integral powered subwoofers to provide high-quality sound from gorgeously sculpted aluminum enclosures. Five years ago, when I reviewed the Mythos STS, I was so impressed that I called it “one of the most exciting products that I have come across in a long time.”

Since then I’ve been impressed by other Definitive speakers, including their BP-8000 series of bipolar floorstanders, also with powered subwoofer sections; and the more conventional but extremely high-value StudioMonitor bookshelf models. Based on my experience with those speakers I’ve anticipated getting in for review a pair of Mythos ST-L SuperTowers ($4999.90 USD per pair) more eagerly than I have any product for some time. The Mythos ST-L was first unveiled last September, at the 2013 CEDIA Expo. After an agonizingly long wait, a pair of review samples finally arrived at my door.

Definitive design

So when I first heard that Definitive Technology was working on the new ST-L, I wondered how they could significantly improve on such products as the Mythos ST and STS SuperTower, which included a lot of forward-thinking engineering and were already innovative and excellent. After speaking with acoustical designer Tim Gladwin and reading some of DefTech’s promotional materials, it became clear to me that their approach was to significantly rework every aspect of the Mythos ST in what they describe as a “meticulous rethinking” of the original. Although the Mythos ST-L looks outwardly very similar to the ST, little in the new speaker remains unchanged from the old.

The tweeter has a new 1” magnesium-aluminum dome -- a first for Definitive, whose previous dome tweeters were made of pure aluminum -- and a magnet 59% bigger, with a longer coil gap, than the one in the Mythos ST’s tweeter. The result, DefTech claims, is flatter response and much less distortion. The two new 5.25” midrange drivers are from the third generation of DefTech’s Balanced Double Surround System (BDSS) drivers, with larger motor structures and a mushroom-shaped phase plug, called a Linear Response Waveguide (LRW), designed to smooth the speaker’s off-axis frequency response. DefTech’s BP-8000 and StudioMonitor models have second-generation BDSS midrange drivers, but the iteration used in the Mythos ST-L is further improved, says DefTech, by the inclusion of an LRW made of machined aluminum, to draw heat away from the motor assembly.

Definitive Technology ST-L

The Mythos ST-L’s two midrange drivers are not identical. In one, the surround is convex; in the other, it’s concave. The peaks and valleys in one driver’s spider are, respectively, valleys and peaks in the other’s. One driver’s voice-coil has aluminum wire clad in copper; in the other’s coil, only heavier, all-copper wire is used. DefTech found that this combination performed better than a pair of either type, producing less distortion and a more linear response across a greater bandwidth. The midrange drivers and tweeter are housed in a sealed, injection-molded enclosure, to isolate them from the backwave from the built-in subwoofer. The midranges are crossed over to the tweeter at 2366Hz with a 12dB/octave rolloff via high-quality air-core inductors and Mylar capacitors. The high-pass filter for the midrange drivers is acoustic -- they roll off mechanically within their sealed enclosure at 12dB/octave without the need for electrical filters, which Definitive feels would add distortion.

Definitive Technology ST-L

The built-in subwoofer has also been significantly upgraded from the ST. The 10” x 6” “racetrack” driver has a new cone woven of polymer and carbon composite, and a completely redesigned motor with a larger magnet and longer voice-coil with heavier wire. The new driver has 25% more excursion and is driven by a more powerful 1200W, class-HD amplifier with 56-bit digital signal processing, taken from Definitive’s top-of-the-line subwoofer, the SuperCube 8000. It’s coupled to two planar passive radiators, also 10” x 6”. The bass level is no longer controlled by a volume pot on the rear panel, but with microprocessors: buttons on the rear panel increase or decrease the amount of bass, and a series of blue LEDs on the speaker’s front indicate the level. The lights go out a few seconds after the level has been set, save for one that glows very dimly, to indicate power on. A remote control is supplied so that bass levels can conveniently be adjusted from the listening position -- a nice touch.

The Mythos ST-L weighs 73 pounds and measures 51.5”H x 6.75”W x 9.5”D, with a slanted top and curved sides. Its newly designed base is made of cast aluminum finished to match the speaker, has threaded holes to accept adjustable stainless-steel carpet spikes or plastic-tipped feet, and is available finished in black or graphite silver. The warranties are three years for parts and labor on the electronic components, five years on the drivers and cabinet.

Definitive Technology ST-L

The Mythos ST-L has two sets of gold-plated binding posts, for biwiring or biamping, as well as a low-level LFE input. The IEC power cord required for the powered subwoofer plugs into the ST-L’s bottom plate (which is a little inconvenient), and the grille, which covers most of the speaker’s front, is attached with plastic pins. There is no plastic latticework on the grille directly in front of the tweeter and midrange drivers, to minimize diffraction; I found that the grilles made no difference in the speakers’ sound. With their grilles on, the Mythos ST-Ls, especially in the graphite silver finish I was provided, looked absolutely stunning. Their lines were so clean, their proportions so perfect, that I wanted to tidy up the mess of cables and power cords behind them so that it would not detract from the speakers’ beauty. I had never before been so strongly affected by the appearance of a review product.

Definitive Technology ST-L

While the Mythos ST-L is spectacular to look at, much of the work that went into the advanced design of its drivers and enclosure is not immediately apparent. This work was done using Klippel analysis and advanced laser measurement equipment. I won’t go into the workings of Klippel analysis here; you can read Hans Wetzel’s description of it in our coverage of the 2013 Consumer Electronics Show. But briefly, the DefTech engineers were able to visualize and test the behavior of the Mythos ST-L’s component parts during the design process to help minimize distortion.


The Mythos ST-Ls took up residence in my main listening room, spaced about 8’ apart, 2’ from the sidewalls, and 4’ from the front wall. I angled them slightly inward, but didn’t aim them directly at my listening position in order to achieve optimal imaging. I used my usual review system: Anthem Statement D2 A/V processor, Oppo BDP-105 universal Blu-ray player, Bel Canto Design e.One REF1000 and Axiom Audio ADA-1000 power amplifiers, and a NuForce DDA-100 integrated amplifier.

Definitive Technology ST-L

I found the Mythos ST-L’s remote-controlled level adjustment extremely convenient in dialing in the bass -- I could precisely control the bass levels of both speakers without having to leave my chair. Depending on which amp I used, I found that the “flat” setting, or a couple of positions above that (which was the setting used when the Mythos ST-L was measured in the NRC’s anechoic chamber), sounded best in my room.

Mythical performance

Five years ago, when I first heard the Mythos STS, my expectations of its sound were tempered by a healthy dose of skepticism -- its slim dimensions seemed to indicate a design that favored form over function. How could such a slender if attractive speaker sound any good? I thought, allowing my prejudices to get the better of me. The Mythos STS’s exceptional sound shattered my preconceptions.

With the Mythos ST-L, I found myself in a different position: having to temper expectations raised by what I know of the performance of Definitive’s other Mythos models. But after only a few minutes of listening, I knew that the Mythos ST-L, too, was a very special speaker. It had a very clean midrange with exceptional imaging capabilities, and responsive and extended bass with impressive dynamic capabilities.

Definitive Technology ST-L

I played music through the new Definitives for a couple of weeks before doing much serious listening. Then, like many reviewers, one of the first things I played to test the Mythos ST-L was something highly dynamic: “Save the Last Dance for Me,” from Michael Bublé’s It’s Time (16-bit/44.1kHz FLAC, Reprise). This track is a great example of big-band sound; through the Mythos ST-Ls the horns sounded sufficiently brassy but controlled, with just enough bite to be realistic, and voices were clear and devoid of sibilance or smearing. Lorde’s Pure Heroine (24/48 FLAC, Lava Music/Republic/HDtracks) was even more compelling. The solid synth bass was reproduced with real authority: the very deep, sustained notes in “Tennis Court” were held unwaveringly, while the more explosive beats of “400 Lux” and “Royals” were subterranean and filled the room while remaining extremely taut. Lorde’s mature voice belies her age (she was 16 when she recorded this album), and her confident singing was realistically reproduced by the slim Mythos ST-L, which proved unflappable even when pushed to extremely high levels. The speaker’s high-output abilities throughout the entire audioband, and especially in the bass, were truly outstanding, surpassing that of many larger, more conventional speakers.

The Mythos ST-L’s highs were extremely clear, but it was its entirely natural sound in the critical midband that made voices sound so amazingly realistic and present. Holly Cole’s spectacular rendition of Leroy Anderson and Mitchell Parish’s “Sleigh Ride,” from her Baby, It’s Cold Outside (16/44.1 FLAC, Alert), had not a trace of grit, and her sultry voice was reproduced flawlessly, from the softest humming to the most powerful peaks. With the Mythos ST-L, I was also able to hear more delineation of individual singers in the complex, mostly unaccompanied arrangement of “Satin Summer Nights,” from Paul Simon’s Songs from The Capeman (16/44.1 FLAC, Warner Bros.), than with any other speaker I’ve had in my system. Whether it was Simon’s easygoing lead vocal, the backing baritone and delicate female voices, or Marc Anthony’s soaring vibrato, there was an extreme purity to the harmonies.

Definitive Technology ST-L

As transparent and neutral as the midrange of the Definitive Mythos ST-L was, it was equaled by that of the KEF R900 ($4999.98/pr.). The KEF was not quite as squeaky clean, but its sound was a little richer and more organic. The Mythos ST-Ls’ solidity of center image was striking, and the lead and backing vocals in “Satin Summer Nights” were placed more precisely -- but those same voices were more fleshed out through the KEFs. Holly Cole sounded a little steamier in “Sleigh Ride” with the KEFs, but David Piltch’s double bass didn’t have quite the speed or definition it had through the DefTechs, especially when he uses it as a percussion instrument. When I blasted through the Definitives ZZ Top’s “Sharp Dressed Man,” from Eliminator (24/192 FLAC, Warner Bros./HDtracks), their powered subwoofer sections reproduced Frank Beard’s kick drum with a speed and tautness that were intense. In fact, the dynamics of the Mythos ST-L, and its ability to play effortlessly at extremely high volume levels, were truly remarkable. Not only that, its lack of distortion let me hear much farther into this less-than-pristine recording, which sounds veiled through most speakers.

Definitive Technology ST-L

While both speakers have a very neutral midrange, the KEF was just a tad more airy and open in the highs. With high-resolution recordings such as the Police’s Every Breath You Take (SACD/CD, Universal), the treble had a sparkling quality it lacked through the DefTech. Not that the Mythos ST-L sounded objectionable -- it sounded very good. It was just that it lacked the slightly more relaxed quality in the treble that I heard with the KEF R900 and a few other speakers that excel in that regard.

In terms of dynamic capabilities, the Mythos ST-L rivaled Definitive’s own bipolar BP-8080ST SuperTower ($2999.90/pair), which also has a powered subwoofer section, but with 12.5” bass radiators, a 12” driver, and a 455W amplifier. Both very soft vocals and the loudest orchestral passages were clearly reproduced by both speakers, but the Mythos ST-L’s superior midrange clarity and image focus created a more holographic soundstage than I’ve heard from many more expensive speakers. Sure, the BP-8080ST did provide a little more extreme low bass with Daft Punk’s “Solar Sailer,” from the Tron: Legacy soundtrack (16/44.1 FLAC, Walt Disney), but “Seven Drums,” from Dadawa’s Voices from the Sky (16/44.1 FLAC, Warner Bros.), sounded punchier and more controlled through the Mythos ST-L.


Definitive Technology’s Mythos ST-L SuperTower elevates “lifestyle” speaker design to a new level of performance with its high resolution, clear and neutral midrange, and incredible dynamics. A true high-end design in every respect, it should hold its own against any speaker near its price, and even against some that cost considerably more. Based on its sound alone, the Mythos ST-L is a surefire recommendation. Add its gorgeous styling, and the fact that its built-in subwoofer allows it to fill a room with sound when driven by an amplifier of only modest power, and it’s the complete package -- and a considerable improvement over the lofty standard set by DefTech’s own Mythos ST and STS models.

. . . Roger Kanno

Associated Equipment

  • Speakers -- KEF R900, Definitive Technology BP-8080ST
  • Amplifiers -- Axiom Audio ADA-1000, Bel Canto Design e.One REF1000 and eVo6, NuForce DDA-100
  • A/V processor -- Anthem Statement D2
  • Sources -- Oppo BDP-105 universal Blu-ray player, Asus Aspire One 722 computer running Windows 7 and foobar2000, Bel Canto Design mLink USB converter
  • Cables -- Analysis Plus Solo Crystal Oval interconnects and Black Oval 9 speaker cables, DH Labs Silver Sonic DV-75 digital interconnect, AudioQuest Carbon USB cable
  • Power cords -- Essential Sound Products MusicCord-Pro ES
  • Power conditioners -- Blue Circle Audio Peed Al Sea Thingee, Zero Surge 1MOD15WI

Definitive Technology Mythos ST-L SuperTower Loudspeakers
Price: $4999.90 USD per pair.
Warranties, parts and labor: three years, electronic components; five years, drivers and cabinet.

Definitive Technology
11433 Cronridge Drive, Suite K
Owings Mills, MD
Phone: (800) 228-7148, (410) 363-7148
Fax: (410) 363-9998