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Positive Feedback ISSUE 37
may/june 2008



100asl loudspeakers

as reviewed by Larry Cox






GamuT L-5 speakers and ATC SCM 20-2A powered speakers.

E.A.R. 864 preamplifier both with a mix of NOS tubes.

Apogee Mini DAC, 24/96 DIY DAC. Amazon Model 2 turntable with a Moerch DP6 arm and a vdH retipped Koetsu Rosewood Standard, and a Audiopath 4 tonearm cable.

Ensemble Dynaflux interconnects and speaker cables, Oritek X-2, Silver Audio Silver Bullet 4.0's and Audiopath tonearm cable. Supra EFF-i balanced interconnect between preamp and powered speakers, Supra DAC cable with WBT connectors, Supra Lo-Rad Mains power cords as borrowed cables, Kubala Sosna Emotion power cords and interconnects.

A Lovan Classic Rack, Townshend Seismic Sink, assorted Vibrapods, Final Labs Daruma III isolation bearings, Black Diamond #3 and #4 cones, with Black Diamond Whatchamacallit's, DH Cones, Discsolution, ASC Tube Trap Bass Trap and assorted other stuff. I hear the differences these items make, but only use them to optimize if the review isn't going well. Too much work to swap out a piece and balance it on Darumas and then take that out and repeat the process. Using all these consistently is a pain as what works with one component isn't a welcome addition for another.


I'm ruined, or at least I'm staggered and awash with the aplomb, vibrance, power and finesse of spending a weekend with ATC's 100asl Tower speakers. My bank accounts will not release the $27,000 asking price for these huge, imposing speakers. Nearly four feet tall, 16 inches wide and nearly two feet deep, you can't miss the speakers' imposing size, though with a few days time, they started looking like welcome pillars in our large listening room.

The tower speakers are, I believe, ATCs doffing of a cap to the domestic world where consumers think that speakers, and especially very large speakers, should not be on stands, but should be one piece of wood from top to bottom. I expect, however, ATC believes that their stand mount speakers have tighter bass.

Each is the size of a small refrigerator, sporting 15" low frequency driver, 3" mid-dome and 1" tweeters, coupled with active filtering and amplification of 250, 100, and 50 watts, respectively. ATC delivers a lot of speaker, certainly at about $166.67 a pound for the 150 pounds per side speaker, it's not chopped liver and leaves even the most costly lobster far behind. Unlike said liver and lobster the thrill and joy of listening to 100asls will last long after the recollection of said meal has dissolved and disappeared from your life.

I was serendipitously "loaned" the speakers for a few days, which was either a few too many or, in my estimation, way too few as part of completing my review of my own ATC 20-2asl speakers. Thanks to Will Ritter at In the process, I've left behind aspiration for any other speaker. I can't imagine wanting anything more, well, except for something prettier to look at.

When my wife set eyes on the speakers in our living room her jaw dropped, wind escaped from mouth and she shuddered at the sight of the squat and imposing speakers. Well, if not artistically, finished in a darker walnut wood, they resembled I know not what, except that my wife thought them something that shouldn't be in her living room! After hearing the title track from Mark Knopfler's "Golden Heart" at live volume levels she turned and smiled, saying, wow, maybe they aren't so ugly after all. And after a weekend with them, she repeated that they were a very special speaker. She said ours remained special, too, if just not quite so special. Speakers that are paid for are much easier to enjoy than the variety that requires payments!

With an ease at all frequencies, and a prodigious and unforgettable bottom end these are speakers that end questions about sufficiency, or at least their sufficiency. Listening to Gabriela Lena Frank "Mestizo Waltz" (Keith Lockhart/Utah Symphony) from Reference Recordings (which is hardly a waltz, unless it's a waltz of tectonic plates) put the recorded venue in my listening room, or at least a smaller rendering of it. It was fantastic, absolutely fantastic. While my overachieving 20-2asl speakers deliver bass, they don't fill, pressurize, and massage you with the bass the 100asl's are capable of. I suppose ATC's 150s, 200s or 300s produce more bass or a larger sense of music, but I can't imagine it being meaningfully larger or more valuable.

These speakers are tight, tight, tight. I don't mean pinched, just that they don't add any of their own bloat at any frequency, at least none that I could detect. That lies, I surmise, with the active speaker design. Treble extension and midrange body were very satisfying, though with the deeper foundation, there seemed to be more space for images and instruments. My reference to the "Mestizo Waltz" should not put in your head that every recording suddenly has deep bass, or sounds "full" because they don't. In some instances the bass response was absolutely no different than my reference speaker. For example, Ry Cooder's "Jesus on the Main Line" from Paradise and Lunch, while a typical rock recording just didn't have the bottom end that the "Mestizo Waltz" produced. And, again, perhaps due to the recording, the image size was smaller and less fantastic than the Mestizo.

My listening was far too short to constitute a "review," though it was enormously enjoyable for me. Three days is long enough to have some fun, learn something about my room and system, but not for definitive judgments. I did take a few things away from the experience.

First, ATC speakers all seem to have roughly, if not exactly, the same timbre one speaker to the next. I've listened to or owned ATC's 7s, 10s, 20s (passive and active), 35's, 50's and now 100s. What I conclude is that ATCs are a bit like Lego blocks, they're somewhat interchangeable, with the choice of speakers mandated by the size of your room (to accommodate the bottom end, and have a place to park the speakers), and of course, your pocket book. Our listening room, at 5500 cubic feet, easily accommodated the output of the 100s, even if the size of the speakers was a bit much visually, perhaps a lighter wood would have made the rosewood veneered speakers seem less imposing.

Secondly, for the first time I hear what Dave Clark has been talking about when he said, "small speakers sound small." Awash in 42" of speaker height, and bass down into the 20s, if not teens, my listening experience was immersive, with sound above and below me, akin to a surround system. My 20-2asl speakers instead provide a small window from which the same music emanates, though this is true of every small non-omnidirectional speaker. My wife and I certainly enjoy our speakers, but would prefer to live with the 100s, no question.

There aren't a lot of chances to listen to a speaker like this, and not many reviews to read given the price, weight, and relative scarcity of the speakers. But, if you get the chance, you'll hear why ATC owners usually trade up within the line from smaller to larger speakers. They are simply an unmitigated delight. Thanks to Teresa Kregling at for arranging my time with the speakers. Larry Cox

ATC 100
Retail: $27,000

Flat Earth Audio
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