GOODSOUND!GoodSound! "Equipment" Archives

Published February 1, 2002


Axiom Audio Epicenter EP125 Subwoofer

Subwoofers may just be the most misunderstood components of them all. When the uninitiated think of subwoofers, they probably conjure up visions of adolescents gyrating to the throbbing thump-thump offered up by poorly designed speakers with exceedingly large and under-damped woofers. But savvy listeners know that this is not what good bass is all about. While bass may rank low on the priorities lists of snobbish audiophiles (clean, detailed midrange and smooth, extended treble top their lists), they also know that no audio system is complete without good bass, and that there is more to good bass than the feeling of being kicked in the gut. Much more.

Contained within deep-bass frequencies are spatial cues that can lend a truly three-dimensional quality to the soundstage. Without low bass, music can sound as though it was being performed in a high school cafeteria: flat, acoustically dead, and constricted. Add the proper amount of bass and the apparent size and specificity of the recorded venue can expand exponentially.

Most listeners have experienced the effects of poorly defined bass. Bass that is too loud or seemingly loose and ill-defined blurs the intricacies of the rhythm and thus bogs down and obscures the music's timing. Taut, well-controlled, articulate bass is quite another thing. It increases the dynamic contrasts of the music and gives it a sense of liveliness and a heightened sense of timing, along with more highly differentiated dynamic shadings.

The Axiom EP125

Selling for $380 and rated down to 35Hz, the Axiom EP125 is a small, powered woofer module designed to augment the bass reproduction of Axiom’s smaller speakers or to add bass excitement to home theaters. While not rated down to the 20Hz range of music's bottom octave, the EP125 does extend far enough to flesh out the output from most stand-mounted speakers and even some floorstanding ones.

Designed to squeeze into any system and any room, the diminutive EP125 (15.25"H x 11.75"W x 12.5"D) weighs in at only 20.5 pounds. Enclosed in the black-oak wood-grained vinyl-finished enclosure is an amplifier rated at 125W and an 8" aluminum-cone woofer. Located under the woofer are two of Axiom’s signature corrugated Vortex Ports.

On the enclosure's rear panel are the amplifier controls and inputs. It is with this control center that I encountered my only real quibble with the EP125. Though it does feature two speaker-level inputs, there is only one low-level RCA input (as well as an RCA output -- intended, I suppose, for daisy-chaining multiple subs). I guess Axiom has geared the EP125 toward the home-theater crowd who will only require one low-level input (connected from their processor’s LFE output), but as a music-first guy, I would have preferred two RCA inputs that can be fed directly from my preamplifier outputs. Filling out the rest of the amplifier's control plate is a continually adjustable low-pass filter (labeled at the control’s extremes of 30Hz and 150Hz), a volume control, a two-position phase switch indicating 0 and 180 degrees, a power on/off switch, a line fuse, and an IEC connector for the power cord.

I have to acknowledge that the two speaker-level inputs did accomplish their mission, and the two lengths of speaker wire I used to connect the EP125 to the outputs on my power amplifier did come in at a lower price than would a pair of RCA interconnects of appropriate length. I used the Axiom EP125 with the company’s M22Ti SE speakers, a Yamaha DSP-A1 receiver, and a Pioneer DV-525 DVD player.

And the band played on

GRP Live In Session [GRP-D-9532], a studio-recorded live CD, is filled with good music, well-recorded drums, and powerful electric-bass lines, which made it a good demo disc for the EP125. All of the previously mentioned benefits of subwoofing came through on "Oasis." Switching in the EP125 did indeed give the music a more highly defined character. Where before the presentation was somewhat bleached-out and vague, the EP125 gave it newfound life, detail, and presence. Even microdynamic detail was increased. Music had a greatly heightened sense of texture. This dynamically charged presentation also featured a more highly contrasted resolution. Without the subwoofer, Abe Laboriels’ bass lines were merely hinted at; with the EP125's addition, they fleshed out to the point of being visceral. At 5:47 into the song, the drum kit is featured front and center, and the EP125 gave it a more commanding presence on stage with a newfound authority and size. The trapset actually seemed to occupy more space on stage.

The opening bass notes on "Rit Variations" were impressive for both their weight and detail. Here the bass drum and the bass guitar seemed to vie for control of the song’s rhythm, and the EP125 did a pretty darned good job keeping up. While not quite as detailed or clean as larger and more expensive subs can be (but not always are), it formed a union with the M22Ti SEs for a top-to-bottom wholeness that was greater than anything I’ve heard from floorstanding speakers in this price range. In addition to the added weight and authority, the Axiom sub offers greater adjustability to the equation than any similarly priced floorstanding system is likely to provide.

"The Beat Goes On" from Patricia Barber's Companion CD [Blue Note/Premonition 7243 5 22963 2 3] demonstrated something that perplexed me. The song is structured around a very strong and prominent acoustic bass, and it took the EP125 to fully bring that bass to its intended prominence. But what surprised me was how the greater bass extension, weight, and power actually brought into greater relief the sound of the bass strings slapping against the neck of the instrument. These "clicks" were well above the range of the EP125, but without the sub they just didn’t seem as there.

Just as with the GRP disc, the performers on the stage were more three-dimensional as each performer occupied a more focused position on stage. Activating the EP125 had the effect of increasing tonal delineations by sharpening them. And even where deep bass was not present, dynamic contrasts were again heightened.

At the end of the listening session I couldn’t help but throw the EP125 to the wolves. Knowing full well that I was asking too much from the diminutive woofer, I put on James Horner’s Casper soundtrack [MCAD-11240]. The opening "No Sign of Ghosts" contains some deep synthetic bass. The EP125 surprised me with how well it hung in there. In direct comparison to larger, more expensive subs, it did lack somewhat, but most listeners would have to be impressed at what this does at its price. There was a little bass doubling (overloading) at some points, but most of the time the bass-drum strikes were rendered so cleanly that I could sense the tautness of the drum skin (which is not too tight!) and the room was traversed with wave after wave of bass. The rest of the disc is chock-full of bass events that lend a dark-and-ghastly, foreboding character to the music, and the EP125 did a very good job of conveying that mood.


Axiom has scored yet again with the EP125 subwoofer. Yes, even from within Axiom’s own line you can find subwoofers that go louder and lower, but if you are just looking to fill in some of the more important bass frequencies that your main speakers omit, the EP125 does a very fine job. With an emphasis on tight and musical, the EP125 will lend a surprising amount of weight to most affordable stand-mounted speakers, while it also delivers the other goodies that bass fanatics crave.

Price of equipment reviewed

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