March
2021

Country of Origin

Switzerland

Vox Sub D15

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, Denafrips Terminator+ clock-synced to Gaia/Avatar, Soundaware D100Pro SD card transport; Preamp: Vinnie Rossi L2 Signature with Elrog ER50; Power amps: LinnenberG Liszt monos; Headamp: Kinki Studio; Phones: HifiMan Susvara; Loudspeakers: Audio Physic Codex; Cube Audio Nenuphar; Aurai Audio M1 [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 Krion and glass amp stands; Sundry accessories: Acoustic System resonators, LessLoss Firewall for loudspeakers, Furutech NCF Signal Boosters; Room: 4 x 6m with high gabled beam ceiling opening into 4 x 8m kitchen and 5 x 8m living room so no wall behind the listening chairs
2nd system: Source: Soundaware D300Ref SD transport; DAC: Denafrips Terminator; Preamp/filter: Passive Preamplifier icOn 4Pro SE w. custom 4th-order/40Hz hi-low pass;
Amplifier: Crayon CFA-1.2; Loudspeakers:sound|kaos Vox 3awf, Zu Submission 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: ~4x6m
Desktop system: Source: HP Z230 work station Win7/64; USB bridge: Audiobyte Hydra X+; Headamp: Kinki Studio Vision THR-1; Phones: Audeze LCD-XC on Forza Audio Lab cable; Powered speakers: Fram Audio Midi 120
Upstairs headfi/speaker system: Source: Soundaware A280 SD transport; Integrated amplifiers: Schiit Jotunheim R or Bakoon AMP-13R; Phones: Raal-Requisite SR1a, Audeze LCD-2, Final Sonorous X & D8000, HifiMan HE-1000; Loudspeakers: Acelec Model 1
2-channel video system: Source: Oppo BDP-105; DAC: Kinki Studio; Preamp: Wyred4Sound STP-SE II; Power amp: Pass Labs XA-30.8; Loudspeakers: German Physiks HRS-120; Room: ~6x4m

Review component retail: TBA

Beans have been spilled. 'twas my email header. Cause was a note from a manufacturer. With a Zoom request for a review, he'd mentioned that "by the way, Martin of sound|kaos was asking me for a special amp version for a subwoofer project he's working on and you're apparently involved with so he said. He actually sent me a link on your website but I had no time yet to peruse it. Maybe we can talk about that too if you have time."

That was actually the first I ever heard of it. Now I had to ask Martin. "Ah… just can't keep a secret in this business. Well, it wouldn't be the first time you end up being the catalyst in a project of mine. I'm presently working on a big sub. Of course aside from needing the right amp for it, the other main ingredient will be the filter. In November I'd ordered a carbon copy Ebaen SE preamp from Pál. Once you had put the icOn Pro4 review to bed, I thought I had all the ingredients for a proper musical sub. As you know, my previous sub projects never really hit the right 'musical notes'. And then the Gradient Box came along to have me ask Pál to put SK on top of his OEM client list."

"So there you have it: 2 x 15" Audio Technology woofers in a pretty streamlined layer-cake box of Birch ply, as compact as I can make it with a solid wood top. I recall you saying that none of the dipole or RiPol subs you heard made it much below 30Hz. Add Pál's Gradient remote-controlled filter. Add an ace amp in one minimalist box with the filter. Hey, you have to aim high to hit the right notes. There's even been thought of a smaller sub (10") with two satellite speakers with 11cm Enviée + Raal ribbon. Now that would be a neat little setup. Just doing my usual ducking and diving."