This review page is supported in part by the sponsors whose ad banners are displayed below
The 23-year old was far from discouraged however. He simply embarked on a sly trick he’d play on his colleagues during a strategy meeting the following day when discussions on new loudspeaker designs were on the itinerary. Overnight he recorded a stone shattering glass, then massaged levels according to his notions on the transient precedent effect. During the meeting, he triggered his concealed tape recorded only to cause massive irritation – one because the accident sounded so real; two because the room didn’t have stone floors, just plush carpet. The glass shouldn't have shattered like it. When he revealed his stunt, some in the assembly were duly miffed because they’d just flogged his theory the day prior. Others were enthused and desirous to learn more. This however wasn't to be. Reime’s division fell prey to an internal company restructuring and got eliminated. That was the beginning and temporary end of his shock wave theory. It would hang in limbo for many years to come.
A chance encounter with Dr. Burkhard Schwäbe during a 2004 Leipzig trade show picks up our narrative again. Schwäbe had led Grundig’s audio division to spearhead their Fine Arts series and later made waves with his OTL amps under the Eternal Arts  label. Reminiscing together about those days, Schwäbe suddenly recalled that strange broken glass incident only to reactivate in Reime a half-forgotten childhood dream. You absolutely must do something about it, Burkhard insisted. He put the bug back in my ear as it were.


A year later Reime walked along the beach in Fuerteventura musing quietly about his shock-wave speaker. It clearly required a solid stone plinth. With our story now caught up with the present, what type of speaker did the Klangfluß K1 eventually develop into as a production model?

The K1 measures 154cm tall and weighs in at 100kg per side. Half that mass goes to the monolithic granite plinth. While particularly the airbrush models suggest little of Bauhaus minimalism, the form-follows-function motto, so the Klangfluß team, does apply strongly. The stone base isn’t there for looks but to add mass for firm floor coupling and to suppress floor resonance. Its convex profile disperses the downfiring woofer’s radiation in all directions and its surface was kept deliberately rough to minimize upward reflections. The precise spacing between speaker and plinth naturally is strategic rather than arbitrary.

The cabinet’s gently pyramidal form factor runs 4° upright edges to make production more challenging for Marcus than a rectangular box. While the team experimented with perfectly vertical edges, the final gradation proved acoustically superior by killing a former enclosure mode between 100 – 300Hz. The enclosure runs 22mm Ply/MDF composite plates. The outer finish is up to the buyer and may be all manner of lacquer skins, 3mm wood veneer, gold leaf or jewel encrustation (the latter was custom ordered once already) and dissimilar treatments for left/right channels. The final sticker reflects the finish labor and material costs. The insides remain unchanged of course. The composite panels are fitted with 4.5mm sheets of acoustic absorption material sourced from a business friend active in flooring solution. This is followed by 5cm of sheep’s wool affixed to the walls rather than stuffed in the box (which, I was told, would undermine its pep).

The Klangfluß K1 is a sealed box without internal chambers. The careful reader might have anticipated a tri-partitioned affair, woofer downward, midrange in its own sub chamber firing forward, tweeter again downward tucked inside its cap. Not quite. The downfiring woofer is the same unit as the one visible on the baffle. Both operate in the same 60-liter volume and feed off the same paralleled signal, making the K1 a two-way. 3-way experiments were less satisfactory because phase errors bled through.


The mid/woofer is a mildly modified 6.5’ honey-comb affair from Mivoc. Forum posters routinely trip up over this driver because it demands only about €50/ea. to seem ill-suited to a very expensive box. Gerd Reime was nonplussed. From a sales politics angle, we’ve surely done ourselves a disservice with this driver. I initially resisted it myself. The Mivoc tip originated with Herr Schwäbe. I frankly thought it ill-considered to build a state-of-the-art speaker around. But Burkhard insisted that we listen to it.To shut him up, we did.
Stopover at Richard Baumers of Hifi Schmiede in Ettlingen who owns a pair of K1 in concrete finish

Blind listening tests with two listening panels of 10 participants each including professional musicians as well as ‘normal’ listeners evaluated 10 different mid/woofers for tonal neutrality, dynamics, transparency, staging and bass definition on a scale of 0 – 5 points. The cheapest driver from Mivoc won. What to do? Buy into an expensive but inferior driver for image spin reasons? Out of the question.


The tweeter too is from the same supplier and mounted ‘freely suspended’ at the top of the speaker. It fires down at a massive 9.5cm Ø sphere for omnidirectional dispersion. The K1 is delivered with three pairs of spheres dubbed HF resonators (one stainless, one sand stone, one solid wood) and replacing the balls is claimed to alter the sonics. More relevant in general is the chosen radiation pattern. The K1 is an omni over its entire bandwidth, with the special feature that up to 2.5kHz there’s a paralleled direct radiator on the front.

Why omni? The team wanted a divorce from the slavish stereo triangle to liberate the music within the room irrespective of a fixed listening position. As per the Klangflußlers, usually the speaker determines where to sit since it won’t sound as good outside the sweet spot. The K1 deliberately creates a far broader optimized listening window to allow for greater placement choices. You’ll shortly see for yourself how I’ve set them up in my own home promised Herr Reime. Okay.
A further pro-360° argument explains that since musical instruments don’t radiate uni-directionally, an omni is closer to reality. Also, highly directional speakers suffer a few strong reflections whereas the K1 generates a more diffusive sound field with many far lower reflections which are spread out over a broader band to cause fewer issues. With inspections top to toe complete, there remains a small box next to the K1 which doesn’t merely contain the crossover but also the shock-wave conditioner. Transient energy compression occurs already in the recording process. It starts with the lazy mass of the microphone diaphragm. This compounds in the playback chain and particularly so the loudspeaker. High moving mass damps transient intensity while the usual filter networks absorb further energy.


The issue is how to return a dose of the live vibe to the music. Hence our somewhat dry term ‘conditioning’. We have to condition the amplifier signal to compensate for the inevitable losses in the recording/playback chain. That’s where our crossover comes in.


The Klangfluß filter quite conventionally separates at 2.500Hz at 12dB/octave. The specified filter slope is only relative to activated motion however by using parts which don’t reach full filter effectiveness before. This usually tolerated side effect is thus deliberately exploited to pass the shock waves mostly unfiltered before actual attenuation kicks in. Aside from that, our filter works like any other and even though our gains seem small—we only make 3dB around 2.500Hz—that’s the vital range and the missing boost.

I visited Klangfluß purely out of curiosity. Their technical approach and general presentation seemed quite ‘different’. After a day's visit, I can confirm that it indeed is. This includes—and here I was surprised—the general vibes if you will which the team of principals emanated. I had the clear impression that these three mature gents, without economic necessity or pressures, simply pursued a private dream. Klangfluß feels like a passionate project.  Because its creators now view the K1 as competitive—actually better than like-priced offerings—they of course would like to successfully market it as such. But it’s clear that the K1 was never conceived from a sales angle. It’s not a straight fit but odd outsider.  That makes it interesting even sonically. The key word is again different.

The most conventional aspect of the K1 is its tonal balance – perfectly even, not a tad forward, harmonically cohesive top to bottom and crystalline clear. Attack and speed in the bass are far from normal however. They're plain awesome and as such a real rarity. Even extension is more than respectable despite ultimate impact obviously being limited by the choice of 6.5’ woofers. Whether the K1 thrills or bores—I expect quite polarized reactions—will squarely hinge on its unique combination of soundstaging and dynamic response.


On soundstaging, you might invoke shoreless. Kiss the usual rectangular stage edged by the boxes good-bye. Grander, deeper and broader, these speaker flood the room with music when appropriate. This depends on the recording of course. Those who like to can, as Herr Reime does, space the K1 six meters apart, then aim them headphone-like at each other to hunker down about three meters removed from the ground line. Reime served up Puccini’s Turandot. No longer did I sit amongst an imaginary public to observe the action upfront. I was the bloody conductor. In a giant semi circle ‘my’ orchestra sprawled around me replete with highly realistic front-to-back layering rather than utterly banal equidistance. Geezus. Whether I’d need this every day is a different matter but this shift in perspective was massively good fun.

But even that wasn’t the real secret. I’ve heard other omnis before and must admit that I routinely missed a bit of snap, drive and kick. The K1 is shorthand for kick with a capital K. If you associate omnis with diffuse, structurally limp sonic clouds, close the book on that notion too. So much for a teaser on Klangfluß sonics. It’s well possible that I’ll get into a lot more details at a later and more formal occasion. We’ll keep you informed if so...

redaktion @ fairaudio.de
Klangfluß website