To close off, Francine Thirteen's "Queen Mary" packs gargantuan imaging, clear calm vocals and deep bass beats atop occasional dynamically boisterous hand claps. It had everything to fully communicate all the LessLoss features. Bass dug deeper, claps had more snap and body, vocals were more substantial and lifelike, spatial sizing grew noticeably larger. The song felt more intense, enveloping and grander inspite of its somewhat slow-paced rhythm. At that point I had enough to understand how much the Firewall did and how beneficial it was. One last observation looked at poorly recorded rock and metal which becomes too shouty and flat at high SPL. A fair share of music by Idles, Filter and the Corvus Corax "Era Metallum" LP which I dearly adore fits here. The Firewall not only supported such repertoire but also allowed me to enjoy it at really loud volumes. This was a personal win I thoroughly appreciated.

Lastly, it's worth mentioning that 90% of my listening was conducted exclusively with a DIY'd C-MARC headphone cable and pigtail. The listening sessions had started with aftermarket equivalents based on Teflon-insulated high-grade silver-plated copper which quickly fell short where it mattered. These weren't bad cables per se and by comparison to Susvara's stock leash make a noticeable difference. It seems however that the Firewall box fancies its own noise-rejecting cables. Or maybe they're simply better? That's a subject for another story and not mine to tell here. Either way, to my ears the synergy between these products is high enough to consider them in tandem. I've been told that a commercially available C-MARC headphone leash is almost ready and several weeks away from going live.

Susvara's equal generosity of tone, colour, spaciousness, impact, articulation and speed makes them a nicely balanced top specimen. Considering how greatly the LessLoss Firewall elevated my experience with them, I can't think of any other headphones that wouldn't enjoy its company. Again, you don't want to pursue this posh exotic $4'918 booster prematurely. It's for those with fully sorted already locked ‘n' loaded upscale systems of endgame power delivery, resonance attention, cables, the primary hardware but who still are inclined to push further. If you're not there yet, look away. If you do and resources allow, then at least sampling this new LessLoss Firewall makes sense. The tech inside has been around for years and proven highly effective for many people including yours truly. More importantly, it introduces gains very hard to come by elsewhere, especially at this high a dosage. Personally I'm very happy that a Firewall for headphones now is a thing and every bit as effective as its proven speaker siblings. Now you know that it's here, my job's done.

Publisher's comment: When Louis Motek forwarded me the below photo for inclusion, I congratulated him on the new look which retains the proven tankwood advantages whilst finishing more finely. "Upon direct audible comparison with same-shape enclosures, this new resin-infused Kraft paper steals the show most obviously. This solution is really quite remarkable. You hit it from any angle with your hardest knuckle and it just sounds like your knuckle." When I expressed interest to hear this device for myself, Louis was happy to forward me Dawid's returned loaner. Here's my 2nd opinion on that.