Usually, math like 3 x 1 = 5¾ is magical thinking where 'magical' is a friendly euphemism for wishful. If we frame it less friendly and more factual, we say impossible. If we attack the magical thinker's cap to get personal, we call him or her plain nuts. So much for usually. But in hifi, unusual things can happen. Let's call them unexpected occurrences where results exceed the sum of their parts well beyond the normal. To call out such unexpected synergy relies on more than just two or three trials. After all, the first one or two attempts could have been simply inferior. That'd make the last just normal and far removed from anything abnormally brilliant. It's also not about replacing a €1'500 source with a €15'000 one and raving over how much better it plays. That's expected and normal though not always the case. No, what 5¾ is about—and its wacky sum hints at the arbitrary unpredictable nature of it all—is far more abnormal. Supra normal. It's when a well-balanced system anchored by a given pair of speakers or headphones suddenly performs not in typical sideways but other-league mode; and does so not predicated upon a capriciously spendy acquisition. This isn't about the usual spend-more-get-more math. This is about the few happy exceptions of not spending more but spending on the right stuff where what is 'right' isn't at all obvious or even part of the usual MO.


That's because beyond a certain point of well-matched component competency, sideways is what most hifi is about. It's not about unequivocal unilateral betterment. It's about different sets of strengths and weaknesses. It's like an endless progression of ice cream or perfume flavours. If those be from within the same catalogue, they guarantee that each is informed by the same attention to detail, quality ingredients and execution. That's why, beyond personal preference, it happens on the level. And such wholesale leveling is very typical for hifi once we subtract overkill build, bling and redundant specs to consider just what's audible. To come across a balanced combination that truly escapes the horizontal domain and hits the vertical shift into the next higher octave or beyond... that's rare. It's 5¾. This is where Berlin contributor John Darko picks up the thread to introduce a component whose built-in synergy fits this column perfectly.

Five years. Stuck on these eyes (and ears) since 2012 have been the KEF LS50 standmount loudspeakers: coaxial Uni-Q driver; 5¼" mid/bass, 1" aluminium dome tweeter with 'tangerine' waveguide; elliptical reflex port flared at either end plus flexible mid section; curved front baffle; MDF cabinet with internal constrained layer damping. $1'499. During its first year on the market, LS50 sales blew the roof off KEF/GP Acoustics' forecast charts. Such unexpected popularity forced an indefinite extension on the LS50's production, originally intended as a limited edition run to commemorate KEF's 50th Anniversary. No doubt FOMO ('fear of missing out') played its part especially with 2014's limited edition alternative colour combination but what really sits at the core of the LS50's continuing popularity? Perhaps it's KEF's decision to break from the past with a more unconventional aesthetic. Or maybe it's KEF's positioning of the LS50 as a direct descendant—a modern day re-imagining—of the BBC's LS3/5a upon which the company's audio engineers worked several decades ago. Or maybe it's the LS50's more affordable price point when compared to the equally visually striking but considerably more costly Blade floorstander that lent the LS50 its Uni-Q driver array.

Five years in the LS50's company means I've hooked 'em up to a broad range of amplifiers and pushed and pulled on their capabilities. A steady flow of reader emails spilling on the back of two DAR articles that detailed (some of) these experiences remind us that interest in sourcing optimal upstream electronics for the LS50 remains as strong as ever. At 85dB, your flea-watt SET amplifier can stay in its box. Going big on raw output power provides the most direct shortcut to LS50 success: go all-in-one class D with a Wyred4Sound mINT, a Peachtree 150/300 or more high-end the class A/D hybrid Devialet Expert 200. The LS50 nourishment game isn't only about watts per channel. The NAD D 3020 showed itself to be tonally lean when piping 30 class D watts into the LS50's nominal 8-ohm input. That experience sits in stark contrast to Vinnie Rossi's Mosfet LIO module that brings home the bacon from just 25wpc. The difference likely falls to the latter's high-current delivery. Ditto Australia's Redgum integrateds. Both Black Series RGi35 and wooden-fascia'd Amplifolia RGi60 come without the bells and whistles of in-built DACs and phono staging but deliver big time on the high current, guzzled greedily by the LS50. These were my favourites until a pair of Wyred4Sound's class D mAMP monos leapfrogged them on scale and drama. For electronic music especially, EJ Sarmento's monoblocks might be peerless at their price point. The sting in the tail is their call for a preamplifier; Wyred4Sound's matching mPRE adds a spoonful of treacle to the quicksilvery essence of going DAC direct with AURALiC, Mytek or Resonessence Labs.

With each setup, sound quality varies. Some amplifiers sound better than others. With the wrong amplifier hook-up, a customer might dismiss the LS50 as a sub-par performer. At the other extreme, with a better amplifier supplying the go juice, the LS50 might sing beautifully. Welcome to the tyranny of choice where the "which amplifier?" guesswork is educated at best. Answers only come from trial and error. Churning gear until we find The One™​​ can be expensive business. Saving us from wasted time and money comes the KEF LS50 Wireless; for $800 on top of the passive version, we net bespoke fit amplification, DAC and network streamer. These come not as external boxes but are fitted inside each loudspeaker cabinet. This isn't only a game of space saving or loudspeaker cable elimination.

"They're not actually wireless", squeal the literalists. True. Power cables are required, one for each speaker. An Ethernet cable joins the left loudspeaker to the right. Know that the powered KEFs also demand a robust wifi network. Hard-wiring the LS50 Wireless into the home network with Ethernet cable becomes essential when troubleshooting connectivity issues. An absence of gapless playback when streaming to the LS50 Wireless over the network via UPnP will be a deal-breaker for some. Roon Readiness could be added by KEF in time and via firmware update. Ditto Spotify Connect. Ditto MQA. Readers are reminded that such decisions and their timing fall to KEF's GP Acoustics HQ in Hong Kong. Nothing is guaranteed until it shows up for real. In the meantime, a 3rd-party streamer is recommended. Sonore's microRendu adds Roon Readiness over USB and in a tidy package. A Bluesound Node 2 piles on Spotify Connect and MQA compatibility. 

Amplifier and transducer in the same enclosure? "That's never gonna work!", the anti-vibration obsessives say. This isn't only an exercise in tidiness. Internal electronics allowed KEF's Kent-based engineering team to exploit technical know-how that, under the hood, is wired differently than a passive rig. Connected to a pair of passive LS50, each outboard amplifier's output signal must pass through a passive crossover network made up of resistors, inductors and capacitors—so implemented as to divvy up signal between drivers and smooth any frequency response anomalies—which dissipate a percentage of signal power as heat. The amplifier engineer knows not to which loudspeakers his box will be connected. He must design his circuit to cope with myriad impedance-swing possibilities of a thousand-and-one transducers. An outboard amplifier like those designed by Wyred4Sound, Vinnie Rossi, Peachtree, Devialet and Redgum must accommodate numerous loudspeaker models and technologies, not just the LS50.

The LS50 Wireless (DAR review here) are an active loudspeaker design with digital inputs and digital crossover. The right-hand loudspeaker plays goalie on all inputs: Bluetooth, network, USB, Toslink, analogue (digitised on entry). The incoming signal is passed onto a DSP engine that implements volume control and smartphone app-controlled signal customisation according to the loudspeakers' placement, room size and acoustic makeup. This same DSP engine executes the crossover in the digital domain and, crucially, prior to D/A conversion and amplification, one DAC and amplifier per driver, two of each per box. Each driver enjoys its own DAC and amplifier - 200 watts of class D for the mid/bass and 30 watts of class A/B for the tweeter. The latter: a) are no longer forced to operate at full bandwidth; b) can be tailored specifically to the driver's input impedance plot and c) are wired directly to the driver's voice coil. With the 'wireless' version, not only do I/we hear the LS50 as the KEF's Kent-based engineering intended but their performance gets some serious uplift over several of the big-dollar passive setups deployed by this commentator over the last five years.

Doing the passive paso doble at the DARhaus July 2015.

At the DARhaus in Berlin, the LS50 Wireless show better bass extension, a greater sense of clarity, more arresting dynamics and more detail than the passive LS50 powered by: Vinnie Rossi's LIO irrespective of external DAC; a Peachtree nova300; and Devialet's big-dollar Expert 200. Time with the LS50 Wireless has shown me that KEF subtract separates, speaker cable and a whole bunch of cash for an end result that kicks the collective arse of many more expensive outboard amplifiers used to power their passive equivalent. Only one passive LS50 setup gets close to its active brother's performance levels: a pair of PS Audio BHK Signature 300 monoblocks connected to the red LS50 via AudioQuest Rocket 88 loudspeaker cable and fronted by PS Audio's BHK Signature preamplifier and DirectStream DAC fitted with the Roon Ready Network Bridge II. In juicing the Red Devils, the PS Audio system offers thicker tonality and greater muscularity and contrast the active newcomer as cleaner, leaner and a soupcon more punctilious in delivering micro detail. The actives dig deeper into lower bass and play it sharper with player outline definition. The PS Audio-fronted passive counter with a few extra degrees of warmth, their handling of cymbal splash a little more forgiving. In pitting this passive system against its twin-box active alternative, hairs could be split all day long...

...until we do the math on the PS Audio system: $15'000 for their monoblocks, $6'000 for the preamplifier, $6'000 for the DAC, $800 for the streamer and ~$800 for the AudioQuest speaker wire. The passive system's electronics alone sum to $29'000! Compare that to $2'200 for the LS50 Wireless. Now the active KEF setup competes with a passive LS50 system costing ten times its retail price. So sharp is the LS50 Wireless' value-for-money quotient that one could add the Sonore microRendu and Bluesound Node 2 and still find oneself sitting pretty with pie-in-the-sky performance/$, looking down from on high on the separates and integrateds required by the red boxes. From the LS50 Wireless system we get performance that exceeds the sum of its parts way beyond that which is expected or usual. To wit, KEF miscalculate 3 x 1 heavily in our favour​ and answer with 5¾. And then some. That's built-in synergy which takes the guess work out of the equation and saves serious money while at it.