Darko: Active Loudspeakers
Across town at Hansa we’d almost certainly find active loudspeakers perched above the mixing desk. You don’t have to go too deep into Google to find photographic evidence of active speakers from Dynaudio, PMC, Yamaha or ATC being used in recording studios around the world.
And yet at Hifi Im Hinterhof in Kreuzberg, one of Berlin’s most prestigious audio and home cinema retail outlets, we find active offerings from Genelec and Sonos drowned out by a chorus of passives from the likes of Audio Physic, B&W, Cambridge Audio, Dali, Harbeth, KEF and Monitor Audio - all of which require outboard amplification and loudspeaker cable.
This scenario isn’t atypical. Active loudspeakers are few and far between in the audiophile world. Audioengine are well-known as stalwarts of the audio show circuit despite the vast majority of their customer base living outside of the audiophile ghetto.
Making more upmarket in-roads are Dynaudio’s Xeo 2 - a terrific all-in-one solution for smaller rooms. For those wanting to drive a slightly larger space and prioritise imaging and layer separation, the KEF X300A Wireless are a terrific starting point.
Teufel are Germany’s biggest loudspeaker manufacturer. From their flagship store and online, they sell a range of loudspeakers, predominantly at more affordable price points, the majority of which are active designs. Also commonly seen in Germany’s big box retailers are active loudspeakers from Canton and Magnat.
Move beyond entry-level territory in the audiophile world and the active loudspeaker herd quickly thins: Dynaudio’s Xeo 4 and Xeo 6; Genelec 8351A, Manger S1; Avant Garde Zero 1; PMC AML-2, the latter skirting the pro audio world where talk of forensic listening might be a priority.
But not all active designs trade in down to the bone analysis of music. Many are most enjoyable, especially if/when EQ-d according to taste and one’s room. Perhaps the audiophile world needs to take another look actives?
Back at my apartment in Mitte, I sit in front of a pair of Genelec G Two (US$700/pair) fed by an AURALiC Aries Mini (also in white) and pull up some Grant Lee Buffalo with an iPhone app. With the amplifiers sitting inside the loudspeakers, this is a three box hifi system for small rooms. No outboard amplifier or loudspeaker cable required. (Side note: Hifi im Hinterhof recommend pairing the G Two with a Bluesound NODE 2).
It shouldn’t escape us that the Genelec/AURALiC pairing sells for a shade more than the 6m run of AudioQuest Rocket 88 wire that joins the neighbouring ELAC Uni-Fi F5 to a pair of PS Audio BHK monoblocks—amplifiers designed for optimal full bandwidth performance irrespective of the loudspeaker attached: planar or dynamic, ported or sealed. The PS Audios, like all standalone amplifiers, are a one size fits all design in which the audio signal is amplified before it is divvied up by the loudspeaker’s passive crossover network.
The baby Genelecs do it differently. It’s crossover first, amplification second. Each loudspeaker’s crossover is implemented with active (powered) components. It sends the split signal to a pair of amplifiers—one for the tweeter, one for the mid/bass—whose outputs are wired directly to the driver’s voice coil. With no interceding passive components, each amplifier’s raw power need not (necessarily) be so high. Many loudspeaker engineers also point to active crossovers being less prone to phase errors than their passive counterparts.
Furthermore, sitting post-crossover, each amplifier need only take care of a limited frequency range and—this is a biggie—its output can be tailored specifically to the driver’s impedance as it varies with frequency. This kind of optimisation just isn’t possible with a passive + outboard amplifier setup because the loudspeaker isn’t known.
Then comes EQ. On the rear of each Genelec loudspeaker dip switches accommodate adjustments to bass and treble according to taste and/or room/desk positioning.
KEF’s all-new LS50 Wireless (US$2200) offer similar EQ options via a smartphone control app: “How big is your room?” and “Are the speakers sitting on stands or a desk?” it asks; but perhaps the most compelling reason to go for the LS50 Wireless is financial prudence. The activated version gives us a hi-res network streamer and D/A conversion on top of bespoke amplification. It’s a high-end hifi system in a box.
We’d have to spend thousands (not hundreds) on an outboard amplifier to land the passive LS50 inside the same zip code as the active equivalent. And that’s before we even ask ourselves “Which DAC?” and “Which streamer?” KEF’s premium for going all-in on active? US$700. The KEF implementation differs from Genelec’s in that its crossover and loudspeaker optimisation are executed in the digital domain. Only after EQ is applied and the signal is digitally divvied up between drivers is it handed off to the D/A converters that precede each amplifier module: 30 watts Class A/B for the tweeter, 200 watt Class D for the mid/bass driver.
The Genelec and KEF argument for active loudspeakers could hardly be more compelling....
...and yet audiophiles continue to resist their charms. Why ride the agony and ecstasy of matching an outboard amplifier to one’s loudspeaker of choice when we know that, all other things being equal, it won’t perform as well as an equivalent active implementation?
We might liken the audiophile approach to system building to buying a car from two separate manufacturers: transmission from BMW; engine and chassis from Mercedes.
What if this mix-n-match lottery could be replaced by a middle ground where the two car companies consulted with each other?
Now our eyes turn to Vinnie Rossi and Spatial Audio’s Clayton Shaw. Rossi is working on an active crossover/EQ/amplifier LIO module for Shaw’s forthcoming X1 Uniwave loudspeaker. With the loudspeaker a known quantity, Rossi can tailor his analogue-domain active crossover and quartet of amplifiers (two per channel, one per driver) to optimise the X1 Uniwave’s performance.
Rossi’s amplifiers will talk to the X1’s drivers directly and their output impedance will be tailored to the corresponding transducer’s input impedance thus giving us damping factor consistency that might otherwise be all over the place.
As with the aforementioned KEF and Genelec loudspeakers, we trade amplifier flexibility in for a significant uptick in sound quality; an objective performance level unattainable by the same loudspeaker with passive crossover network and driven by an outboard amplifier.
Increasingly more manufacturers are seeing actives as a reliable direction for future product development.
Piquing my interest of late are Klipsch’s R-15PM that add Bluetooth to an otherwise TOSLINK- and USB-accessible DAC and, more unusually, phono pre-amplification. At US$499, they’ll make you look twice at a pair of Sonos Play:1.
Taking a more feature-trimmed route are the UK’s Acoustic Energy who have recently announced the activation of their AE1 loudspeaker: 2 x 50watt Class A/B amplifier per driver, per speaker and a 4th order minimum phase (analogue) active crossover. At £1200/pair, they’ll sell for only £200 more than 2011’s passive AE1 Classic.
Some audiophiles may still balk at an inability to roll their own amplification but others - myself included - are more than happy to sacrifice this BYO approach if it means no more loudspeaker cables, a lower system box count, room/position EQ and bespoke fit internal amplification.