Unless fundamentals hit high enough to involve the super tweeters like the occasional cymbal or violin flageolet—now those sounds stood out as being unnaturally bright—listening at stout volumes still didn't make the sound bright per se. The tone cylinders themselves rarely lit up. Only what shone through them was stronger. Moving from more potent diamond to magnesium then shifting to the 18kHz high-pass toned this down some. Still, on balance the effect was a bit special as in, movie FX. To hit the bull's eye like Kroma's Mimí had done would have required padding down the omnis a bit. At very low listening SPL meanwhile, the effect was stunning like finally getting properly corrected eye glasses.

For whisper sessions, a steeply toed-in nearfield setup for quasi surround immersion is ideal.

Another benefit I honed in on now perhaps because the super tweeter action at standard to high levels was a bit too pronounced? Any and all steep percussive sounds located extra accurate and very spiked. This behaviour seemed to better line up their leading edges. Scientists even tell us that human hearing localizes sound by their transients. The cleaner less scattered (phase-shifted) in time those are, the more accurately our ear/brain assigns a very specific location. With more harmonic content audible now, transient brain registration seemed enhanced. Think about a car door slamming, a wine glass hitting your kitchen floor, a bird crashing into a window pane. In real life, such unexpected quite violent "gun-shot" noises produce a shock wave impact which triggers our adrenalin. Nearly all hifi systems struggle to reproduce that same immediacy. By comparison, their percussive sounds feel canned and buffered in cotton taffy. On this count of shock-wave believability, the super tweeters ratcheted up higher realism. Struck objects like wooden sticks on rims, a guitar's body slaps or a saxophone's player clacks exhibited more suddenness and ultra specific localization. As a result, hard-driven rhythmically taut grooves seemed to gain a higher degree of beat fidelity.

Scanned image from the CD booklet.

Spin up a collector rarity like the new Joël Gare recording with its chromatically tuned Swiss cow bells. Those took the artist 20 years of collecting and commissioning to arrive at a pitch-correct set beyond an octave. With the super tweeters, the subjective verity of hearing oscillating metal molecules at their finest was simply on a different plateau. The action wasn't about extra airiness but about hearing the air being excited and the bells having multiple harmonic layers just as is the case for my Deuter meditation soundtrack. If you're listening to compressed Rock at 256kbps MP3, none of this matters of course. The Fraunhofer compression algorithm considers such extremely low-level data irrelevant to throw it away.

Enter Cube Audio's Nenuphar. It's a uniquely capable Polish widebander of 10" diameter and 30Hz – 18kHz wing span which in this top iteration is backed by an 80-some slug Neodymium motor. With a ~92dB sensitivity based on its published FR graph, not only was this a well-matched combo on relative output, the concept of a single driver with bona-fide bass naturally meant that the mid to high treble would benefit from mild assist. First up was Vicente Amigo's hymnic "Requiem" with the current creme-of-the-crop flamenco singers taking solo turns plus singing in massive unison. Now their fabled inner fire burnt brighter. This refers to hoarse vocal elements which, perhaps, we could equate with membrane breakup or guitars in overdrive. Aside from the fundamentals with their own harmonics, there are these additional rusty aspects from deliberately trained/strained vocal cords, an effect highly priced in typical cante flamenco but also showing up with Turkey's Sezen Aksu. The omnis peeled out those raspier grainy layers which Nenuphar's triple-whizzer drivers merely hint at by themselves. Even though the lighter Maple looked better against the deep-yellow drivers with gold phase plug, the walnutted diamonds did all the same things just better still. On the octave-doubled vocal unison passages, the individual voices separated out even stronger.

Chris Sommovio Black Cat Cable Lupo biwire  speaker cable fed the main speakers and super tweeters from shared amplifier terminals.

With the speakers' designed-in rake mellow enough to cause no slippage, the Avantages stayed put without BluTak. For a permanent installation, I'd certainly secure them. Being loaners, I didn't want to gunk up the black felt pads. Going walkabout in the adjoining open kitchen, I noticed how even well off-axis, the super tweeters had improved the already excellent point-source focus of these speakers. Even with my back turned to pile up a sandwich on the granite island, certain percussive sounds popped up with extra startle power as though on a laser-mapped 3D checkerboard. Back in the hot seat, I explored this added degree of soundstage specificity with now undivided attention. True, it was a heightened stereophonic trick. It was hyper-realist – better than life. But when all the visual markers of a live performance are deleted and ears must stand in for eyes, I enjoyed this artifice very much. Super tweeters for best soundstage mapping would be the bumper sticker. Might it deliver that message to perplexed hi-end virgins in inner-city gridlock traffic?

"Do you think the guy in the car in front of us does ultrasound surgery?"

Probably not then. Even committed audiophiles at large aren't familiar with this magnitude of super tweeter benefits; if at all. Such a reaction wouldn't be that far off, however. In terms of sorting and separating, 'surgical' is quite apt if the main speaker isn't unduly confused in the time domain to begin with.