M

Reviewer: Srajan Ebaen
Financial interests: click here
Main system: Sources: late 2020 Retina 5K 27" iMac with 40GB RAM and Ventura 13.3, 4TB external SSD, Audirvana Origin, Qobuz Sublime, Singxer SU-6 USB bridge, LHY Audio SW-8 network switch with SOtM iSO-CAT7 isolator, Sonnet Pasithea DAC; Active filter: icOn Gradient Box 2; Power amplifiers: Kinki Studio EX-B7 monos, Goldmund/Job 225; Headamp: Cen.Grand Silver Fox; Phones: HifiMan Susvara; Loudspeakers: Qualio Auido IQ + sound|kaos DSUB 15 on Carbide Audio footers, Audio Physic Codex; Cables: Complete loom of Allnic Audio ZL; Power delivery: Vibex Granada/Alhambra on all source components, Furutech RTP-6 on amps, Furutech DPS-4.1 between wall and conditioner; Equipment rack: Artesanía Audio Exoteryc double-wide 3-tier with optional glass shelves, Exoteryc Krion and glass amp stands; Sundry accessories: Acoustic System resonators, LessLoss Firewall for loudspeakers, Furutech NCF Signal Boosters; Room: 6 x 8m with open door behind listening seat
2nd system: Source: Shanling M3 Ultra, Soundaware D300Ref SD transport, Cen.Grand DSDAC 1.0 Deluxe; Preamp/filter: icOn 4Pro + 80Hz active filter, Vinnie Rossi L2 Signature w. ER50; Amp: Enleum AMP-23R; Loudspeakers: MonAcoustics SuperMon Mini, Dynaudio S18 sub; Power delivery: Furutech GTO 2D NCF, Akiko Audio Corelli; Equipment rack: Hifistay Mythology Transform X-Frame [on extended loan]; Sundry accessories: Audioquest Fog Lifters; Furutech NFC Clear Lines; Room: ~3.5 x 8m
Desktop system: Source: HP Z230 work station Win10/64; USB bridge: Singxer SU-2; Headamp/DAC: iFi iDSD Pro Signature;  Headphones: Final D-8000; Active speakers: DMAX SC5
Upstairs headfi/speaker system: Source: smsl Dp5 transport; DAC: Auralic Vega; Integrated amplifier: Schiit Jotunheim R; Phones: Raal-Requisite SR1a; Active DSP speakers: Fram Midi 120
2-channel video system: Source: Oppo BDP-105; All-in-One: Gold Note IS-1000 Deluxe; Loudspeakers: Zu Soul VI; Subwoofer: Zu Submission; Power delivery: Furutech eTP-8, Room: ~6x4m
Review component retail: ~€75'000/pr

I've proselytized on Ripol/cardioid bass for many waxing never waning moons. Now an active Danish speaker signs on that dotted line with 1.5kW of Pascal amplification powering the same directional bass principle in a visually most distinctive manner. Dual force-balancing 10" woofers DSP compensate for 16Hz reach. They work to 200Hz on a rapid 48dB/octave exit. This extends their resonance-minimizing dispersion advantage across domestic listening rooms' typical range where reflected sound dominates and deleterious modes occur. The midrange works to 2.4Hz above which the tweeter takes over. The visual approach differs from Ecobox and Voxativ as two firms which already integrate such bass systems with full-range speakers. Likewise for standalone Ripol subs from ModalAkustik and sound|kaos. Dutch & Dutch, Silent Pound and Amphion's Krypton 3X pursue cardioid dispersion for the midrange instead not bass; while Kii which extent down into the low frequencies shape their cardioid dispersion with heavy DSP and far more drivers.

FS = resonant woofer frequency. In a Ripol frame, the left driver's 24Hz in a sealed box becomes 14Hz whilst reducing enclosure volume to 1/4th. That's in addition to the dispersion advantage.

This new Dansk speaker enjoyed a soft early June launch in Copenhagen. Their site's Stories pages and particularly a lengthy White Paper present an in-depth cover on the thinking behind this photogenic speaker. It measures 135cm tall, 45cm wide and 61cm deep yet despite its minimalist framing weighs a solid 75kg, all electronics built into the plinth. This isn't just a frilly industrial design exercise. There's sophisticated engineering involved.

On Thursday June 8th, treble clef hosted their private wine'n'dine party at Spisehuset in Copenhagen's famous meat packing district on the Slagtehusgade. It was the first showing of their TCA-M as the sound installation part at Denmark's annual 3daysofdesign event. I had the invite but not being a gastro groupie, no travel fever. I thanked chief designer and founder Ole Siig and explained that to make up for passing on their gala event with head chef Torsten, I'd happily review his creation instead. "I've put you in lead place for a review loaner set. Timing isn't clear yet but I will most certainly keep you posted. With your previous proselytizing on Ripol systems, I think you'll really appreciate what we have accomplished with our patented TCA-M bass system and the overall hard-to-explain so must-be-heard sound of the speakers." Ole's comments referred  to a brief industry feature I'd already penned and sent him the link to. With a formal assignment on the books, I turned that copy into this review intro.

Meat packing district's water front.

Prior to the loaners materializing, we already had these views on M for Main. Unlike passive speakers, there are no binding posts. We instead enter XLR analog or AES/EBU digital. It's a virtually complete system in a box; just without the box. Just as invisible is a concrete-based foam absorber built into the woofer hemispheres to mechanically silence them. This tracks an Alex Ridthaler claim, holder of a long-expired Ripol patent, that whilst this 'folded OB' loading principle benefits from the smallest possible housing to lower its drivers' resonant frequency, it also requires compensation for otherwise unavoidable internal resonances. If you're unfamiliar with Ripol bass, Google it. Aside from its 'super' dipole dispersion, its major point of distinction from conventional bass systems is that whilst those operate as pressure generators, a Ripol works as velocity converter. That wants woofer parameters to match. To work properly means more than firing two generic woofers at each other through a front slot of arbitrary width then venting them through two more slots out the back in anti phase.

It's a well-proven principle which in actual production loudspeakers remains peculiarly obscure. Perhaps that's because there doesn't seem to exist a mathematical model in which to properly simulate optimal Ripol behavior¹? If so, it relies on iterative prototyping. And to keep driver diameters contained, it mandates compensation for its 6dB/oct. roll-off below self resonance to virtually rely on active drive plus DSP. That leaves passive boxes flapping in the wind. With woofers, that's the last thing we want. Ripol loading increases radiation resistance on its drivers which builds in superior self stoppage i.e. damping. By triggering less room resonance and less box talk, this benefits the time domain. Bass notes start/stop far more punctual to avoid overhang and its minor droning. Less resonance equals faster bass when anything that arrives late—room reflections which travel longer, time delay from thru-cone reflections leaking out of a box—is slow by definition. In those terms slow bass is no myth. It's majority consensus. By design we expect fundamentally different behavior from the treble clef. That's especially so when it runs its unconventional bass loading up to 200Hz. That avoidance of lateral reflections and reduced front-wall involvement controls the bandwidth across which all home-based listening rooms exhibit their gravest problems. In all fairness, that's free/invisible room treatment. You obviously see speakers. To make sound, that's set in stone though a promise of 16Hz reach typically implies something far bigger. What you won't see are acoustic bass traps. Those must grow physically large to absorb long wavelengths. That's what makes Ripol bass so clever. It's high IQ when we don't want a living space festooned in unsightly room treatments like a recording studio. Ripol bass isn't just faster and cleaner. It seriously reduces the pervasive overlay of reflective mud on the critical midrange because it doesn't involve our room the same.

As you see, I didn't say proselytizing for nothing. It's simply required when this topic gets so little airplay in our press. For Ripol there's no pre-existing recognition like ported or sealed bass which even hifi newbs have heard of. Until there is, admirers of cardioid bass must bang their own drums. Cue the Kesselpauken of Richard Strauß's Thus spoke Zarathustra.
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¹ "A Ripol in a folded box limits its useful upper range to avoid an inherent 150Hz resonance peak. That's too low to couple to a superior dedicated midrange. Our execution raises the peak to ~370Hz so we can execute our crossover at ~220Hz to comfortably avoid the peak and enjoy the added benefit of still broader Ripol directivity for reduced room interactions."