Taking it to 100

Reviewer: Srajan Ebaen
Financial interests: click here
Main system: Sources: Retina 5K 27" November 2020 iMac (i5, 256GB SSD, Ventura 13.3, 40GB RAM), 4TB external SSD with Thunderbolt 3, Audirvana Origin, Qobuz Sublime, Singxer SU-6 USB bridge, LHY Audio SW-8 switch, Cen.Grand DSDAC 1.0 Deluxe, Sonnet Pasithea DAC; Active filter: icOn Gradient Box 2; Power amplifiers: Kinki Studio EX-B7 monos, Goldmund/Job 225 on subwoofer; Headamp: Cen.Grand Silver Fox; Phones: HifiMan Susvara, Meze 109 Pro; Loudspeakers: sound|kaos Vox 3awf + sound|kaos DSUB15 on Carbide Audio footers, Audio Physic Codex, Qualio IQ [on loan] Cables: Complete loom of Allnic Audio ZL; Power delivery: Vibex Granada/Alhambra on all source components, Vibex One 11R on amps, Furutech DPS-4.1 between wall and conditioners; Equipment rack: Artesanía Audio Exoteryc double-wide 3-tier with optional glass shelves, Exoteryc 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 into Soundaware D300Ref SD transport to COS Engineering D1, iFi iDSD Pro Signature or Denafrips Terminator Plus 12th Anniversary firmware; Preamp/filter: Vinnie Rossie L2 Signature or icOn 4Pro, icOn 4th-order/80Hz active filter; Amplifier: Crayon CFA-1.2; Loudspeakers: MonAcoustic SuperMon Mini or Acelec Model One + 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; DAC: legacy Auralic Vega; Head/speaker amp: Enleum AMP-23R; Speakers: EnigmAcoustics Mythology M1;  Headphones: Final D-8000
Upstairs headfi system: Source: Shanling M3 Ultra, Soundaware D300Ref; DAC/headamp: iFi iDSD Pro Signature; Headphones: Meze 109 Pro
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: €3'850

Hz, not km per hour! In the wake of my Aavik C-280 review, I was disappointed only that my sample had loaded their revised 30-80Hz filter board not the original 60-160Hz version. Then I remembered. My icOn Gradient Box 2 can hit 120Hz. Why cross over so high to a speaker that's good to 30Hz? It makes sense if we have a cardioid aka Ripol sub whose dispersion pattern eliminates sidewall reflections, lowers front-wall gain and builds in superior self damping. Less reflective more direct bass creates superior time-domain behavior and serious attenuation of whatever room modes fall within the cardioid bandwidth. Very much not as per usual, tacking on such a subwoofer is not primarily or at all about bolting on extra bass to our speakers. It's about tightening up bass textures to be less ringy. We make them far more similar to our higher bands whose dispersion narrows with frequency. Less ringing and bloom mean superior stoppage. That's reduced overhang so higher precision and better timing. It also means more coherent textures not firm fit mids and trim treble mated to loose 'woolly mammoth' bass.

What going from my previous 80Hz/4th-order Linkwitz/Riley transition to 100Hz accomplished in the above context fell within the remit of higher self damping. Our 3-way speakers' woofers work to 600Hz. They retain plenty of cover even being already down -6dB/100Hz. With two 15" woofers facing each other inside the sound|kaos sub at close proximity then exiting through a slot facing me whilst their out-of-phase rear emissions hit immediate cabinet walls before exiting through two openings aimed at the front wall, those Audio Technology drivers exhibit still more punctual braking than the high-zoot 9½" SB Acoustics Satori woofers of the speakers.

Applying more cone area for more air motion also benefitted upper bass heft, blackness and kick violence. I tried 120Hz but preferred 100Hz. The transition from 'cracking' low end to 'more elastic' mids feels more seamless at the slightly lower handover.

The moral here is simple. If we have the required functionality of a smart active analog dual-slope crossover, we can play with its adjustments and really nail our ideal blend. We're even free to change our mind and alter the settings many months later. Did you draw a blank over the opening thumbnail of a box against color gradients? It's the Gradient Box filled with hidden benefits locked away in it (or something equivalent like Aavik's €4K filter option for three of their preamps). So get with the program. Make better sound. Get an active sub plus precision analog crossover. Potentially shrink the size/expense of your speakers quite radically. See above. €2K for the monitors, €1.4K for the sub. That combo goes places you'd never guess if you just judged price and size. I have four pairs of +€10K floorstanders in my office. There's good reason why none of them play upstairs. My petite 2.1 combo sounds better; and in this narrower space looks far more attractive.

Taking it to 100 can mean different things. In my hifi book, they all involve a 2.1 segregation of bandwidth labor via active analog precision filters. It's why I ordered a 2nd Gradient Box for upstairs to gain the same flexibility I enjoy downstairs. Until now I've used the above combo of icOn 4Pro autoformer volume and fixed 80Hz/4th-order filter. The new single box combines remote-controlled master volume and 7 different turnover frequencies independently adjustable for the high/low pass and left/right channel. I even gained XLR i/o for the filter. Would I now go to 120; Hertz that is? Options. You don't know what you're missing if you don't have 'em. This includes two firmware versions for the Gradient Box. For upstairs I ordered the original. It's because this DAC lacks volume control. So the master volume is in the filter box unlike downstairs where my converters are variable. There Pál's alternate firmware reassigns his premium volume/balance control chips to generate more than 60dB of potential attenuation on the high and low pass outputs. That's convenient when a sub is passive and driven off a stereo amp without attenuator. Finding the correct sub/speaker balance must always juggle disparate voltage gain between speaker/sub amps plus disparate sensitivity between speakers and sub. Adding extra cut on either leg opens up combinations which otherwise fall outside the window of the original firmware.