Auva SW

Reviewer: Srajan Ebaen
Financial interests: click here
Main system: Sources: Retina 5K 27" iMac (i5, 256GB SSD, 40GB RAM, Sonoma 14), 4TB external SSD with Thunderbolt 3, Audirvana Studio, Qobuz Sublime, Singxer SU-6 USB bridge, LHY Audio SW-8 & SW-6 switch, Sonnet Pasithea, COS Engineering D1, Laiv Audio Harmony; Active filter: Lifesaver Audio Gradient Box 2; Power amplifiers: Kinki Studio EX-B7 monos & Gold Note monos on subwoofer; Headamp: Enleum AMP-23R; Phones: Raal 1995 Immanis; Loudspeakers: Qualio IQ [on loan] Cables: Exact Express Flame, Furutech; Power delivery: 2 x Kinki/Vinshine Tai Hang on amps and source stack, 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, AudioQuest FogLifters; Room: 6 x 8m with open door behind listening seat; Room treatment: 2 x PSI Audio AVAA C214 active bass traps
2nd system: Source: FiiO R7 into Soundaware D300Ref SD transport to Cen.Grand DSDAC 1.0 Deluxe with POW; Preamp/filter: Lifesaver Audio Gradient Box 2; Amplifier: Kinki Studio EX-M7; Loudspeakers: ModalAkustik MusikBoxx + Dynaudio S18 sub; Cable loom: Exact Express Earth; Power delivery: Vibex Granada/Alhambra, Akiko Audio Corelli Corundum & Castello Solo; Equipment rack: Hifistay Mythology Transform X-Frame [on extended loan]; Sundry accessories: Furutech cable lifts, Furutech NFC Clear Lines; Room: ~3.5 x 8m
2nd headfi system: DAC: Cen.Grand DSDAC 1.0 Deluxe with POW; Headamp: Cen.Grand Silver Fox; Headphones: Raal 1995 Magna, HifiMan Susvara
Desktop system: Source: HP Z2 work station Win11/64; USB bridge: Singxer SU-2; DAC/headamp: iFi iDSD Pro Signature; Speakers: DMAX P61 Headphones: Final D-8000, aune SR7000
Upstairs headfi system: FiiO R7; Headphones: Meze 109 Pro, Fiio FT3
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: £270/4 ex VAT

Without bolt receivers, use the flat-top plates instead.

SS. In this year's Sky Original Nuremberg, Russell Crowe plays infamous Nazi leader Hermann Göring facing the war tribunal of Nürnberg and Rami Malek as the American psychiatrist Douglas Kelley tasked with assessing whether he's fit to stand trial. In this very dark chapter of German history, Great Britain were part of the allied forces which ended WWII.

Now in late 2025, it's once again Britain which combats the SS, albeit not as Hitler's feared Schutzstaffel but the structural shyte which subwoofers turd out. Like CNC routers tasked with precision machining don't bolt to concrete only to spread vibrations into neighbouring equipment but decouple via weight-rated viscoelastics like Sorbothane—and engines decouple from their frames—so the mechanical energy generators of low frequencies in home audio should 'float' above not couple to the floor. The most effective means must include size, looks and cost in the equation when our living room isn't a lab in an industrial park. Sinking mechanical vibrations into our home's structural elements can trigger audible resonances, migrate into equipment racks, speakers or neighbouring rooms. That's against top performance. Particularly suspended upper floors are very susceptible. The lower and louder our subwoofers play, the more time-delayed mechanical mud becomes the shit-storm enemy of our sonic SS.

Having had great personal success with Stack Audio's particle-damping isolators beneath my Artesanía double-wide equipment rack and Qualio Audio's IQ speakers, I naturally embraced the offer to test their latest footers. It's the Auva SW not facing South West but aimed at subwoofers. As shown next, they combine a particle-filled damping chamber with a trapped viscoelastic sleeve. The latter comes in six weight ratings to cover tuned compliance from 1-56kg/4. The machined outer aluminium barrel is 50mm tall and 35.4mm across. It can bolt to our infrasonic weaponry via a variety of thread adapters; or interface with the included flat discs shown above. The exact geometry of the elastic insert and its retainer took 19 iterations to perfect. It wasn't left to chance or guesswork.

If particle damping is still unfamiliar, envision the dry sand traps on a golf course. When hitting a bunker, golf balls which can travel up to 245mph don't bounce like their tennis mates do on a composite court. They simply stop. The friction of freely moving grains of sand converts their motional energy to heat. It's super simple but when applied to hifi, a very effective resonance killer. Whilst a buzz kill is the bane of any party, a trap of LF resonances which otherwise disturb our efforts at pristine playback is a silent hero. When its maker doesn't ask the world, even better. On the subject of which, what is the coin drop on a quad of British silence enforcers? £270/4 ex VAT. Incidentally, to combat Brexit funk on value-added tax, Stack Audio use a Dutch depot in Eindhoven to fulfil EU orders.

Preaching the gospel according to young Theo Stack and John Brownbridge.

The animation might suggest that unlike the lateral motion of roller-ball footers, the Auva SW can only displace vertically like an anti jackhammer but there is some horizontal play as well. The 'special sauce' is the combination of material springiness and micro particles in one device that's not unduly massive like the original Carbide Audio footer below whose subsequent generations have duly shrunk to suit more installations. An early adopter with a REL sub commented on Instagram that Stack Audio's SW not only work better than his stock footers but look better, too. And that's certainly a sticking point when you consider my next photo.

15-inch Zu Method sub on Carbide footers which very effectively if enormously combine viscoelastics with multi-layer ball bearings.