Acoustic Energy AE1 loudspeaker JA Follow-up, July 1992

JA wrote a Follow-up on Acoustic Energy AE1 in July 1992 (Vol.15 No.7):

When I reviewed Acoustic Energy's tiny AE1 minimonitor nearly four years ago (in Vol.11 No.9), I was mightily impressed. Enough so, in fact, that I concluded that review with the rather sweeping statement that the AE1 "redefines the art of miniature speaker design." Four years is a long time in the loudspeaker art, however, and I was interested in hearing how the AE1 stood up to more recent designs. I was also interested to find whether my tastes had changed. The speaker may or may not have changed, but had I? Were my sonic priorities the same as they had been in 1988? The AE1s were making an excellent sound in Audio Alchemy's room at the 1991 SCES; I requested a pair for a "Follow-Up" review, therefore (footnote 1).

The AE1 is now distributed in the US by Panor, who have also resuscitated the Dynaco line (footnote 2). Originally $1500/pair, the AE1 now costs $1899/pair in satin black, $2290/pair in rosewood, or $2460/pair in black lacquer (matching stands cost $900/pair), but is otherwise unchanged. It still features a magnesium-alloy dome tweeter and a woofer with a 4.5" anodized aluminum cone. The bass alignment is reflex, with twin 1.25"-diameter ports positioned on the front of the cabinet, and two sets of 5-way binding posts are provided for bi-wiring, these inconveniently inset on the speaker's rear.

Sound Quality
Acoustic Energy recommends 24" stands for the AE1; I used Celestion Si stands spiked to the floor beneath the rug, their center pillars filled with lead shot and stand. Amplification mainly consisted of Audio Research Classic 120 and Mark Levinson No.20.6 monoblocks, the AE1s bi-wired with 2m lengths of AudioQuest Midnight (bass) and Sterling (treble). Front-end components consisted of a Meridian 602 driving a VTL Reference DAC for CD replay and a fully loaded Linn LP player. Preamplifier was the McCormack Phono Drive EPS and the Melos headphone amplifier—you're never going to find that combination in a retailer's—with AudioQuest Lapis single-ended interconnect linking everything. Everything was plugged into the excellent Power Wedge II.

Right from the start of my auditioning, I was impressed with these tiny gems, just as I had been in 1988. They have the uncanny ability to disappear. Never was I once able to locate the loudspeakers by the sounds they emitted; instead, the listening room between and behind the speaker was suffused with the recorded acoustic. The AE1s are image-meisters of the first water. In addition, instrumental sounds both possessed a pleasing lower-midrange palpability and were reproduced with their tonal qualities intact. Yes, the high treble sounded a little too sweet in absolute terms, and there was a trace of "eee" character—the sound of David Abel's Guarnerius violin on the Wilson Violin Sonatas album (W-8722) was shifted toward how it would sound if it had a mute on the bridge—but these were generally inconsequential.

More important was a residual touch of brilliance in the low treble, brought into relief by the reticent high treble. While this did add excitement to the sound of treble brass instruments like the trumpet and cornet—aiding these instruments' brassy edge—it could tend to become fatiguing with ancillary components that were already a little exaggerated in this area. Of the solid-state amplifiers I had to hand, only the Mark Levinson No.20.6 was sufficiently neutral that this didn't become a problem. In general, I found the tubed Audio Research Classic 120 was a more synergistic match for the AE1.

Something that Martin Colloms has been paying attention to recently in his speaker reviews is the "pace," or "timing," of a speaker's bass. I visited Martin on a recent trip to England and questioned him further on this subject. Basically—with apologies to MC if I misrepresent his position here—he feels that a loudspeaker should not achieve its bass extension and low-frequency authority at the expense of bass articulation; the "speed" of the low frequencies, if you will. Now I know that the oxymoron "fast bass" drives the more pedantic of you up the wall. However, I know of no more illuminating phrase that describes the nature of accurately reproduced bass frequencies: the weight of bass-instrument transients follows the articulate leading edge of the sound in a coherent manner, without there being a time-smeared boominess to muddy the sense of musical timing.

All speakers depart from reality in this regard to some extent, though the best that I have heard, such as the Wilson WATT/Puppy, Spendor S100, and Celestion SL700SE get pretty close to the real thing at times. The worst that I've heard—I won't mention names, but you're welcome to plow through back issues—either reproduce bass instruments so that they always sound like they're playing behind the beat, or add a dominating one-note boominess that disguises the true pitches being played.

It is in this aspect of reproduction that the AE1 falls short of the best. In that wonderful 6/8 blues "Tin Pan Alley" from Stevie Ray Vaughan's Couldn't Stand the Weather (Epic FE 39304), bassist Tommy Shannon plays a deceptively simple line that both underpins and propels the music. The AE1s made him sound slightly less propulsive, as though he was out of touch with what the other two musicians were playing. I suspect that this is a consequence of a low-frequency alignment that slightly exaggerates the upper-bass level in absolute terms in order that the listener might not be continually reminded how small a speaker this is. (This is the old "LS3/5A trick.") Nevertheless, if, like Martin, LF articulation is your ultimate groove thang, the AE1 will not be for you.

But this character certainly rendered orchestral music enjoyable, the low strings having plenty of meat on the bone without their sounds becoming oppressively diffuse. Well-recorded piano, too, had sufficient left-hand weight to become almost totally convincing. At no time during Ivan Davis's excellent Grieg piano recital on Audiofon (CD72022, recorded by Peter McGrath in 1987) did I get the impression that I was listening to anything but a normally sized pair of loudspeakers. In the "Rigaudon" from the Holberg Suite, for example, where the sailor's hornpipe theme concludes with a rousing downward-scale phrase, the sound of the piano seemed fully fleshed out.

This was aided by the Acoustic Energy's dynamic ability. Despite its low sensitivity, the AE1 simply went louder before audible strain set in than any speaker with a 4.5" woofer should. It also proved excellent in resolving dynamic contrasts, by which I mean that individual instruments didn't merge into a blur of sound when things got loud, but retained much of their individuality.

For my final set of listening tests, I compared the AE1 with the Celestion 100 that I reviewed last month (Vol.15 No.6, p.193). The Celestion is somewhat bigger and, at $1200/pair, significantly less expensive. Its balance, however, is leaner than that of the Acoustic Energy's, which is usefully more fleshed out in the upper bass and doesn't lose much in overall low-frequency extension. The Celestion's bass, however, is more articulate but, surprisingly, the smaller speaker sounded more dynamic. It would also play somewhat louder before strain set in. Both designs were excellent imagers, though the AE1 again had the edge when it came to overall clarity.

The next contender in the ring was the ProAc Response Two that I had just finished measuring for Corey Greenberg's review elsewhere in this issue. It was immediately obvious that the ProAc is a high-quality performer. A neutral tonal balance and a tight, articulate bass register are coupled with an ease to the sound that belies the speaker's size. Against the AE1, however, which is only 1dB or so less sensitive, it became apparent that the Response Two was not quite as transparent in the upper midrange, and had a degree of mid-high treble grain. Not much, admittedly, but enough to add a degree of sibilance emphasis to Jennifer Warnes's voice on her Famous Blue Raincoat CD (Cypress 661 111-2).

The ProAc's bass was faster than that of the Acoustic Energy's, but the Fender bass tracks on the second Stereophile Test CD revealed the two speakers to emphasize different components of the instrument's intrinsic sound. While the AE1 was a little too nasal, the Response Two got that right but at the expense of sounding too woody in the lower midrange. The Acoustic Energies outclassed the bigger speakers in ultimate imaging ability, but the ProAcs had an overall rightness to their sound, a palpability that, once heard, proved hard to forget. In this respect, they reminded me of the Spendor S100 I reviewed last December.

Finally, the obvious comparison for the AE1 is the Rogers LS3/5A, the speaker that defined the minimonitor genre. A brief listen to my 1977 pair of LS3/5As (reviewed in Vol.12 Nos.2 & 3), however, revealed them to be completely outclassed by the 15-year-younger but considerably more expensive design when it came to dynamics, transparency, treble smoothness, and bass quality. The AE1 would be my first choice for a location monitor.

To sum up
In a sense, the size of a loudspeaker shouldn't matter; all that makes it a good buy or not is the illusion of music it produces in the listening room. Nevertheless, a speaker as small and as expensive as Acoustic Energy's AE1 faces a considerable uphill struggle.

Does the AE1 still "redefine the art of miniature speaker design"? Yes it does, I feel, as I have yet to hear a miniature that equals its balance of virtues (though the Genesis IM-5200 reviewed by TJN last October comes close in some areas). It is also the best-sounding speaker in the Acoustic Energy line. Its recent rise in price, however, brings it up against some stiff competition. The Celestion 100 has a similar subjective bass extension but is both more articulate and 30% less expensive; the Thiel CS2.2 and Vandersteen 3 (I'm currently working on reviews of both) offer more bass and dynamic range for approximately the same money, while the ProAc Response Two and Spendor S100 are more rounded performers, hence better values overall despite being more expensive. And that's putting to one side the performance offered by panel speakers like Magnepan's excellent MG2.6/R.

Nevertheless, if you have a small room, play mainly classical music rather than high-energy rock, and are not an organ freak, the AE1 will provide a superb degree of musical satisfaction.—John Atkinson

Footnote 1: Serial numbers of the review pair, finished in rosewood, were 01005763 and '64.—John Atkinson

Footnote 2: Corey Greenberg is currently working on a review of the ST-70.—John Atkinson

Acoustic Energy
8709 Castle Park Drive
Indianapolis, IN 46526
(317) 849-5880