March
2022

Country of Origin

Slovakia

Super Cubes

Reviewer: Srajan Ebaen
Financial interests: click here
Main system: Sources: Retina 5K 27" iMac (4GHz quad-core with Turbo, 32GB RAM, 3TB FusionDrive, OSX Yosemite. iTunes 14.4), PureMusic 3.02, Audirvana 3, Qobuz, Tidal, Sonnet Pasithea, Soundaware D30Ref SD card transport & USB bridge; Preamp: icOn 4Pro S w. hi/lo-pass filter; Power amplifiers: Kinki Studio EX-B7 mono, Enleum AMP-23R; Headamp: Kinki Studio; Phones: HifiMan Susvara; Loudspeakers: Aurai Audio Lieutenant w. sound|kaos DSUB 15 on Carbide Audio footers, Audio Physic Codex, Cube Audio Nenuphar 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 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: Soundaware D100Pro SD transport clock-slaved to Denafrips Terminator +; DAC: Kinki Studio; Preamp/filter: icOn 4Pro + 4th-order/40Hz hi-low pass; Amplifier: Crayon CFA-1.2; Loudspeakers: sound|kaos Vox 3awf, Dynaudio S18 sub; Power delivery: Furutech GTO 2D NCF; 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: Audiobyte Hydra X+; Headamp: COS Engineering H1; Headphones: Final D-8000; Powered speakers: Fram Audio Midi 120
Upstairs headfi/speaker system: Source: smsl SD-9 transport; DAC: iFi Pro iDSD Signature; Integrated amplifier: Schiit Jotunheim R; Phones: Raal-Requisite SR1a
2-channel video system: Source: Oppo BDP-105; All-in-One: Simon Audio; Loudspeakers: German Physiks HRS-120; Subwoofer: Zu Submission; Power delivery: Furutech eTP-8, Room: ~6x4m

Review component retail in EU: €690/pr

The emailer was reader Russell Dawkins, a welcome voice of reason, resourcefulness and proper inquisitiveness to bridge the two.

"I stumbled upon this interesting speaker design just a few days ago and was intrigued. I thought you would be too, if you aren't already. It's the Super Cubes 5, an active nearfield monitor with apparently outstanding clarity and imaging capabilities due to careful DSP application using FIR filters to correct frequency response and phase linearity (ringing resonances and settle time) in the single driver.

"This last aspect really caught my attention. I think  that settle time is one of the big ignored performance factors in transducer design both microphone and speaker. These are compared to Stax headphones by some for their clarity which I think may be connected with their rapid settling time.

"They do have a flaw which would restrict practical use to obsessive recording professionals and similarly obsessive home listeners and probably desktop only: their extremely narrow listening window. You have to be very close to on-axis to hear the intended tonality so they are not suitable for those wanting a broad sweet spot.

"They manufacture in Russia for the international and non-EU market and Slovakia for the EU market. They seem eager to promote and are apparently liberal with their demo unit policy.

"With me a few posters in this thread have serious credibility: Jantex and b0se. b0se is located in the UK and compares these with Kii III which he owns. I've communicated with Jantex for 13 years and he's been in a position to hear most of the top contenders in monitor speakers due to his studio activity and connection within the industry. A good friend of his is the exclusive importer of Sennheiser and Neumann for Slovenia. Andrew Startsev the designer makes his first specific reply to questions in post #120, page 4 of this thread. I hope this is news to you."

It was. Reading up gets us 5" aluminium widebanders not from Mark Fenlon but SB Acoustics [15NAC30-8, a previous Pro version used Fountek's FW146] in small Sapele-edged 18mm solid Oak cabs built by Kuklin Alexey Yurievich. They measure 20cm³. There's also a 50wpc class D amp with integral DSP and low 5ms digital latency. 3-meter SpeakOn cables are included. In Europe, €690 steals the lot from Bratislava via GLS parcel service. Add ship fees; plus VAT for Switzerland, Norway or Iceland.

With a masters in applied Physics, designer Andrew Startsev learnt to write his own audio software and the algorithm at the heart of the Super Cubes. His tech page explains what that corrects and how. Andrew also operated his own recording studio AV-music.

After my recent Ripol sub adventures eliminating usual overhang or ringing from sub-80Hz room gain, I was my own Russell terrier to hear improved time-domain performance across the bandwidth. Better settle times mean more accurate driver stoppage. Unlike Russell and the majority of contributors in his linked thread, I'm not a recording studio professional, not even an amateur. But like their kind, I'm versed in the virtues of nearfield listening. It's a free solution to minimizing typical room issues. One plays at lower SPL due to proximity and boundaries are often at greater distance to attenuate reflections. This just wants a compact speaker to act as point-source radiator at the ear. Vertical driver arrays which are too tall often want larger distances before they cohere. The arguably most ideal really-near transducer is a small widebander or KEF and Cabasse coax/triax kind.

With Andrew's cubes, we get passive boxes—single drivers in small cabs—plus a suitable external amp with vital custom algorithm embedded and passive cooling. That's an active combo proposition. Just add DAC/pre or variable source.

It's crystal that going cubic with another amp would be stupid. We'd throw away what makes this proposition unique in the first place: proprietary digital-domain correction which goes beyond just the amplitude response to also correct the time domain. Would Andrew be interested in dispatching a loaner pair for the most obsessive close-to-the-sun flyers in our always opinionated home-audio crowd?

I sent out an inquiry within minutes of Russell's email. Naturally we don't expect copious headroom when used outside their intended nearfield app. Those in the recording space report sufficient SPL stability for their mixing/monitoring needs. My desktop's ambient noise is ~28dB. I'm very happy with ±55dB average levels. I have to hear myself think to work. On my loudness score, I felt certain that the Super Cubes would be perfectly adequate. True, audiophile purists will frown at the inevitable A/D⇒D/A conversion inside Andrew's amp with its pure analog XLR inputs.

Here one should ask why the gains from his algorithm wouldn't entirely outshine any potential losses from extra conversion stages. As is, we'll never know. You can't run this system with a digital input signal. But Russell did well to alert us to these cubes.

Nearfield desktop with sealed full aluminium Fram Midi 120 DSP actives with SB Acoustics drivers. Such setups need little size or power. Perspective and resolution can bridge the gap between speakerfi and headfi.

A day later, Andrew responded. "Yes, my Super Cubes are ideal for critical music listening in acoustically untreated rooms. Most of my clients take them to work outside the recording studio. Of course they can be used with any active 3rd-party subwoofer. They have a certain volume limit but will confidently give 75-80dB at one meter, enough for super nearfield monitoring purposes. But these are true control monitors for professional work. They are difficult to use just for listening to music. They give a very linear dry analytical sound. Only well-recorded music will sound good. More than half of your favorite music library might be thrown out."