Acoustic Energy AE3 loudspeaker

Back in the Spring of 1988, I was sent a pair of diminutive two-way speakers that totally redefined for me what miniature loudspeakers were supposed to be about. That model, Acoustic Energy's AE1, may have offered short measure in the low-bass department, but its apparently effortless dynamics, musically natural balance, and tangible imaging made it a winner. It also broke the mold of modern audiophile speaker design by featuring a 4.5" woofer with a metal cone just 3.5" in diameter. (Various companies have experimented with metal-cone drive-units in the past, only Ohm and pro-sound company Hartke having had any previous commercial success, though Monitor Audio now also offers a range of speakers with metal-cone woofers, their Studio line.) Since that time, Acoustic Energy has tried to produce a full-range speaker that built on the success of the AE1, but with only limited success, in my opinion. While their AE2 added a second identical woofer, and offered useful increases in bass extension and dynamic range, I felt it to be too colored in the midrange to be a real audiophile contender (see Vol.13 No.2, February 1990, p.134.)

Now we have the AE3 ($3500/pair), which marries a 7.5" metal-cone woofer (with a radiating diameter of 6") to what appears to be the AE1's drive-units in a considerably larger enclosure. This new driver, carrying the range below 300Hz, uses a 40mm-diameter edgewound, long-throw voice-coil, and is reflex-loaded with four small ports, each 5.5" deep and 1" in diameter. The exterior edges of these ports are gently radiused to reduce wind noise. The midrange unit, which covers the decade from 300Hz to 3kHz, is different from the AE1's mid/woofer, however, having a very low-mass, edgewound, short-throw 32mm voice-coil, which is cooled with ferrofluid. The metal-dome tweeter is also cooled with ferrofluid. All three drive-units are mounted vertically in-line, rabbeted into the baffle.

The 21-element crossover uses audiophile-grade parts, including iron-dust and air-cored inductors, polyester capacitors in the 3kHz filters, and low-loss electrolytics in the woofer filter. Three sets of gold-plated 4mm terminal posts are provided on the rear panel, to allow tri-wiring if desired, while the internal wiring is via 24-strand, 0.4mm-diameter silver-plated oxygen-free copper cable insulated with PTFE. The enclosure is made from 28mm MDF with an internal lining of acoustic foam. The review samples were finished in a knubbly cream paint, as were the matching stands. Twin-pillar designs, with an attractive fluted styling, these can be filled with lead shot. Tapped for carpet-piercing spikes, they support the speakers with four upward-facing spikes, each adjustable in height.

Sound
The AE3s, their bulky grilles left off for the serious auditioning, proved to work best in my room in the positions where the Spendor S100s had done well, 2' from the LPs lining the rear wall and 5' from the side walls. The speakers were initially hooked up to the amplifier with custom-made 5' bi-wire sets of AudioQuest Midnight and Sterling. Halfway through the listening, I obtained a 2m length of AudioQuest's top Dragon Hyperlitz speaker cable, which enabled me to tri-wire the speakers. The increase in midrange transparency was great enough that I advise all those thinking of purchasing these speakers to budget for three runs of good cable. All my comments refer to the sound of the AE3 when tri-wired.

I initially found the sound too mellow. My listening chair places my ears 36" from the ground, which meant that I was level with the AE3's midrange unit. Sitting up so that I was on or just above the tweeter brought up the top octave of highs, so I tilted the speakers forward by placing German Acoustics brass cones under the rear feet of the stands. Pink noise revealed the extreme highs still to sound slightly rolled-off, leading to a mellow balance, though there was very little "vertical venetian blind" effect as I moved my head from side to side, suggesting even HF dispersion. Further down in frequency, the low treble sounded peaky and somewhat bright, though not to any great degree, while there also seemed to be a trace of "aww" coloration in the midrange. The low frequencies were rich and full, with good extension.

The diagnostic soundstage tracks on the Chesky Sampler CD (JD 37) reproduced with good precision, though the out-of-phase image positions didn't sound as phasey as I'm used to. The depth tracks also reproduced well, although the LEDR "Up" track, which is supposed to reproduce as a mono source rising from the speaker position, actually started well above the speaker, presumably due to the speaker response adding to the equalization already present in the recording.

Turning to music recordings, Britten's own 1964 recording of The Young Person's Guide to the Orchestra (London 417 509-2) offers a rich, typically Decca, Kingsway Hall sound courtesy of engineer Gordon Parry. The Acoustic Energies slightly exaggerated the recording's already a-little-too-vibrant treble balance, lending bowed violins rather too much of a wiry character, but otherwise presented the individual instrumental sounds in a most satisfyingly real-sounding way. When a speaker adds resonant colorations in the midrange, the differences between instrumental sounds become diluted. Instead of sounding like discrete entities, separate acoustic objects if you will, they sound more like different flavors of one sound, here acquiring something of a clarinet nature, there something of an oboe nature, but remaining homogeneous. The AE3s passed this test in a mainly excellent manner. The timpani on the Britten recording, for example, both sounded discrete in space and had well-defined pitch centers. As with the violins, however, there was a trace of character in the low treble, which accentuated the metallic nature of trumpets and added a trace of the same color to clarinets in their upper register, though it didn't seem to have the same effect on the xylophone, the individual notes not running together.

If the acoustic models that the brain constructs of reproduced instrumental sounds are fragile, then how much more fragile is the model of the original space in which those instruments played. There are only secondary clues to its nature captured on a recording, these often destroyed by most microphone techniques. What impressed me most with this recording, therefore, was the sense of space thrown by these speakers. Though in absolute terms the image's depth dimension was rather restricted, there seemed to be a wealth of ambient detail apparent, to the benefit of the illusion. Similarly on J. Gordon Holt's recording of the Järnefelt Praeludium on the Stereophile Test CD, the well-decoded ambient detail threw an excellent sense of space around the orchestral instruments, the sound of the trumpet in particular allowing you to "hear the walls" of the recording site.

This combination of the preservation of individual sonic textures and excellent decoding of ambient detail added to the music's ability to absorb the listener. I found the opening of Act III of Tosca—Puccini's most Wagnerian opera, more through-composed than Butterfly or Bohème (except that Wagner could never write a tune at once so beautiful and so tragic as Cavaradossi's "E lucevan le stelle")—to be realistically captivating on the Philips Covent Garden set (412 885-2). Sheep bells and a shepherd's song give way to the encroaching dawn heralded by the clocks of Rome (a spatial effect borrowed by Robert Zemeckis for the opening scene of Back to the Future), every chime presented by the AE3s with its own tone color intact, its acoustic model discrete.

I mentioned earlier that the AE3's bass was full and extended. Subjectively, it appeared to be flat down to below 40Hz, though sub-bass detail—the subway car accompanying the clarinet at the start of that Cavaradossi aria on the Philips Tosca, for example—was readily audible. Organ recordings, too, reproduced with a good sense of the instrument's acoustic low-frequency power. Quantity is one thing, but quality is another. The bass overall seemed somewhat exaggerated in level, which in itself can be quite pleasant, but this was accompanied by a feeling of detachment from the lower midrange that emphasized the disparity in level.

On my Chopin recording on the Stereophile Test CD, for example, the Steinway's left-hand register was too thickened, too heavy to sound real, despite the beautifully palpable, otherwise tonally accurate piano image hanging between and behind the speakers. Some bass notes also seemed to smear across from the right (where they belong) to the left. Sam Tellig's speaking voice on the Stereophile CD also acquired too much chest tone, though that of J. Gordon Holt, which is less dark-chocolate in flavor, came over very naturally.

In my experience, this aspect of reproduction is something which some people are more bothered by than others, who consider it a reasonable tradeoff to make to get a realistic proportion of bass frequencies. But when Guy Lemcoe auditioned the AE3s, though he commented on the wealth of detail made audible by the speakers, he too was bothered by their lack of clarity in the upper bass. In fact, his first comment after sitting in the listening chair concerned the fact that some bass notes on Blandine Verlet's harpsichord on the Astrée sampler offered extra ripeness while at least one other lacked body, leading to a sense of discontinuity between the mid/low bass and the midrange.

Summary
Acoustic Energy's AE3 offers a balance that is both rather bright in the low treble and rather mellow in the high treble, with relatively low levels of midrange coloration and bass that is extended if rather exaggerated in level and somewhat disconnected from the lower midrange. It offers very good, if not excellent lateral soundstaging, with reasonable image depth, and will play at high levels without producing much distortion or listener fatigue. What it does best, however, is offer a superbly transparent, almost full-range view into the stereo soundstage which I found most enjoyable. While expensive with the mandatory stands, not even considering the benefits I found tri-wiring to confer, the AE3 deserves a serious recommendation.

COMPANY INFO
Acoustic Energy North America Inc.
111 Lenox Street, Suite 106
Box 314, Norwood, MA 02062
(508) 695-8090
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