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Dynaudio Accent 3 powered loudspeaker
When it comes to loudspeaker drivers, Dynaudio has earned an enviable reputation for quality and reliability. To use an automotive analogy, they are the Mercedes Benz of the driver universe. If you're a speaker builder, the odds are that you have already experimented with these drivers. And even if you're not a speaker builder, it's quite possible that your speakers use Dynaudio drivers. After all, some of the finest speaker systems in the world do. A case in point is the Duntech Sovereign, which single-handedly embodies almost the entire Dynaudio catalog.
Surprisingly, Dynaudio's line of assembled speakers has never cracked the US market. This, I think, is a reflection of poor marketing rather than product quality. Their kits have been popular in Europe, and according to Madisound's Larry Hitch, Dynaudio's new line of kits is now available in the US (contact Madisound for details).
The Accent 3 is the product of a long gestation period: over four years of research and development. I first ran into an early prototype at a CES about two years ago. Based on a very short listen, I found the tonal balance and dynamics to my liking, and expressed interest in pursuing a full review. Finally, at the 1989 winter CES, Dynaudio's Gerhard Richter declared the Accent 3 ready for prime time, and the show samples were shipped to Santa Fe for review. As far as I know, the review pair represents the only existing samples of this speaker on US soil. Please note also that there is no domestic distribution for this model. The Accent 3s, however, may be purchased factory-direct from Dynaudio through Madisound.
As with other active designs, one of the Accent 3's goals is to control the amplifier/driver interface. In a traditional passive loudspeaker, the designer must make certain assumptions concerning the cable and the amplifier the speaker will be used with. Just how closely these assumptions are satisfied in practice determines the final driver damping, bass alignment, and crossover frequencies. For example, a significant change in speaker-cable impedance from the nominal design value can cause a small shift in crossover points. This is because the frequency response of a passive filter is sensitive to the source as well as the load impedances.
An active speaker represents a scenario where the electronics are by definition intimately mated with a driver complement. In the case of the Accent 3, what you have essentially is a tri-amped speaker system, the requisite amps and crossovers being part and parcel of the electronics interface. Thus, you may indulge in a tri-amped design without the need to purchase external crossovers and additional amplifiers. And best of all—you don't need any speaker cable! In this day and age of "phase noise" and BS-plated esoteric conductors, this item alone could save you a bundle of bucks.
The potential of active designs is, however, dampened by increased complexity. Simply put: there's more possibility for the designer to screw up. A successful design has to master the nuances of driver and amplifier integration. Rarely does a manufacturer possess the in-house expertise to solve both parts of the equation. Either you have an electronics specialist, who regards drive-units as mysterious black boxes, or a driver specialist attempting to bridge the "knowledge" gap. And even if the synthesis is a success, the patient may still die. An active design locks you in to a particular amplifier. You're stuck with its sound quality without the option of upgrading it in the future.
This lack of flexibility may not prove to be a deterrent if you belong to the all-amplifiers-sound-alike school. But having heard the Quad US Monitors recently with Quad's own amplification, I can tell you that for me the mere thought of the Quad '63s being offered "strictly active" with Quad's own electronics is sufficient to induce nightmares. (I hope Freddy Kruger isn't reading this.) This is a clear case of a great speaker being dominated by mediocre amplification, and an example of what could happen in the case of an active design.
Seeing is believing!?
With a modest footprint, sensible mini-tower cabinet proportions, and a stunning rosewood veneer finish, the total visual impact of the Active 3 is modern and elegant. The only obvious indication that this is an active design comes from the heatsink façade located on the bottom of the cabinet's front baffle. The electronics module includes a power supply with a capacity of 500,000µF, and an active crossover network feeding three 150W amplifiers—one per driver. The three channels are said to be "decoupled," and the crossover uses low-noise operational amplifiers. Other than that, I have no additional information concerning the circuitry. However, I presume that, because of space and heat-dissipation constraints, the power amps are biased in class-AB.
Provisions are made for both balanced (4-pin Cannon) and unbalanced (gold-plated RCA jacks) input connections. Slight (±1.5dB) control over the bass and treble is available via a rear-panel switch. The bass is affected over a narrow range from about 30 to 80Hz, while the treble boost or cut operates progressively from 8kHz to 15kHz, reaching a maximum of 1.5dB at about 15kHz. The level of control offered is quite minimal and of questionable utility. I find it much more useful to control the treble balance by adjusting the speaker toe-in angle; increasing or decreasing the amount of off-axis radiation. In the deep bass, a 1.5dB change in output level is on the threshold of audibility, and pales in significance when compared with the effect of room modes, which may be as large as ±10dB.
The driver complement is mounted on the front baffle in a vertical array, but its order is inverted from that of a typical three-way. The woofer is on top, followed by the midrange and the tweeter on the bottom. This places the tweeter below ear level, where, at 22" off the floor, it would typically fire at the listener's kneecaps. I'm not sure I understand the rationale for this geometrical inversion, and hope that Dynaudio can shed some light on the subject in their "Manufacturer's Comment."
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