My main system mollycoddles the LF by outsourcing to a cardioid 2×15" subwoofer on sound|kaos string-suspension footers to literally hang above the floor; with two active PSI Audio bass traps in the front corners working from 150Hz downward; and with a precision analog crossover set to a 100Hz/4th-order hi/low pass from Lifesaver Audio. Though the main speakers' 9½" SB Acoustics ported Satori woofers cross the 30Hz threshold, their omni dispersion creates far more room involvement than the folded open-baffle sub with its lateral nulls and reduced front-wall output. Being curtailed by 2½ octaves of reach, these speakers don't cause vibrational LF problems. With that primary isolation task removed for Theo's ribbed barrels, my focus here was living in a subtly redecorated home of tone. Being able to easily slide the speakers into position on their new felt rings was a nice fringe benefit. My takeway is the usual. Whilst choices abound and with them, effectiveness, looks, size and price, do get your transducers off the floor! Unless they're bass-bereft tiny monitors on spindly stands working background fill at 50dB, you're not tapping full performance.

As far as concrete foundations go, I very distinctly remember a day of barefoot listening on that massive slab in our Chardonne digs. I was shocked to feel bass pulses tickle my feet. High dense mass can make an excellent vibratory conduit. But our eight very happy Swiss years are long behind me. These days I'm on parquet with wooden subfloors. Isolation makes a distinct difference particularly once system resolution is very capable. I find this topic bigger than component isolation except for microphony-prone valve kit, CD and vinyl spinners, hugely bigger than streamers and associated LAN tweaks, upsamplers and digital filters. As we clear away disturbances, smaller and smaller things telegraph. Yet the smart money wants to handle things in proper sequence. Here I consider the off-the-floor speaker topic far from last. If one is allergic or even just sensitive to loose ringy bass textures which are obviously discontinuous with the superior stoppages of the midrange and treble like a flabby arse allied to six-pack abs, it really moves to the forefront of must-do chores. It's the first thing that will improve though there can be multiple knock-on effects depending on our system's overall res. If hifi were a motorcycle, speaker isolation isn't Sunday morning's wash and chrome polish. It's proper tyre pressure.

Sub.way. Not the sandwich or tube, I finally tried Auva 70 under my most critical kit: Dynaudio's S18 upstairs sub, sound|kaos' Gravitas 15 downstairs. As dedicated bass makers they're the most potent mechanical energy generators well past spinning discs, DC-bugged transformers or microphonic capacitors. It was my segue into 2.1 stereo years ago which in fact prompted my deep dive into effective mechanical isolation. In parallel I was exposed to Raal's original open-baffle ribbon headphone which completely bypasses all bass/room/resonance issues. Hearing that became my rabbit-hole pursuit for speaker systems. I'd become infected by a ringy-bass allergy. Once recognized in full because the ribbons subtracted it completely, I lost all tolerance. It's why I don't hear a true loss of LF amplitude. The headphone reference knows it to be fake, a ringy add-on not on my recordings. But I also appreciate that listeners used to big-bottom texturally discontinuous bass invariably interpret effective isolation's removal of the fake extra as a loss of power and weight, not a gain in linearity and clarity that extends well beyond the low freqs.

For the 100Hz-down band Auva 70 came in after my Swiss triple-wire suspension footers. Perhaps Auva 100 would close that gap? What did I listen for in these last A/B? Inner bass textures; remaining differences between them and the higher bands. That's because these next-gen Raal 1995 Immanis triple ribbons act as a continuous reference of bass sounds stopping as cleanly as all the rest. I can wear them like inspector's goggles to check what my 2.1 speaker systems are up to. In conclusion, over my audiophile career I've filled stand columns with sand later cat litter as have many of us. Yet I never considered particle-impact damping a topic to play footsies with. Theo's Auva became my first steamy encounter under that table.

For speakers I now rate repackaged sand traps more than jittery ball-bearing isolators. After 23 years on this beat I still learn. Like other apprenticeships, it's a never-ending process. The more we know, the more we realize how much more we don't. With today's op I found it extra gratifying that Theo Stack and Josh Stephenson represent the new 30-something generation of resourceful entrepreneurs who enter our sector on the manufacturing side. Welcome; and thank you, gents!

Stack Audio respond: I spotted the review last night. Absolutely loved it and the detail you’ve gone into. Exceptional work. Theo & I appreciate the effort you put in. Regarding your comments on the subs, we're quite deep into the R&D and due to get some prototypes for special sub isolators we already designed. Would love to send some over to you when we get them in. Thanks again from all of us here at SA! – Josh Stephenson

Publisher's postscript: Given my exciting finding, I next volunteered for a brief follow-up report on adding Auva 100 to my performance-engineered Artesanía Audio double-wide Exoteryc rack as upgraded floor interface. As it happened, Stack's sand-trap goodness continued. Should I take up golf? Best not. I'd be focused on the wrong things…