Helium 510 versus One18. To capture essentials, first impressions rule. They are naturally stuck on what contrast calls the most obvious change. If they don't really make out anything of substance, that too is telling. For this A/B, no head scratching. Whilst listening to clarinetist Hüsnü Senlendirici, first impressions fired up in this exact and quick succession. First, there was rather greater overall scale. Second, there was more overt immersion in extreme detail. Three, this was particularly apparent from the upper midrange on up. Clearly resolution had undergone a decisive uptick. It was curious that this telegraphed first in the upper registers all the way into the realm of fine cymbal, triangle, brush work and tinkly far right-handed piano. But when the next track pushed some disco-esque bass in my direction, it's very dry punch and power left no doubt that this area too had undergone the makeover to cross off the fourth mental box.
 
What at first I found rather more decisive and primary than bass per se? The gains in vocal band then treble clarity. For low bass in my quite extreme <1m nearfield and sharply toed in where acoustic losses are super marginal, I'd need to reach for some deliberate ambient massive attacks. That'd be for later. For now and blatantly obvious also with some Vassilis Tsabropolous on accompanied solo piano [You, Utopia Records] were the improvements above the bass. I had less blur, overlay and cob webs between the notes. To be honest, my spider sense hadn't tingled with the Helium 510 about any cob webs neither. This was another instance of not knowing what you don't know until you do. I would thus stress that the first and foremost advantage of the passive radiator loading wasn't more bass per se. It was less shadowing from the competitor's port. Reducing such secondary interactions—the infamous side effects which the really small print of medications always warns about—made for primary benefits in music's core range. That was about even more lucid intelligibility and separation. The quantity of hearables went up to put it plain. Imagine a pianist of such dexterity as to dispense with lifting the damper panel altogether. He doesn't rely on undamped sustains to bridge challenging acrobatics. Hence there's no unwanted running together of certain notes, no intermediary overlay just from lack of manual technique.


Inquiring into why the added sense of scale which had registered nearly instantly, I paid closer attention to the Greek pianist's work in the two octaves above middle C. This range had more weight and body. The reasons rather stared me in the face: the One18's larger driver. Hello! Scale of course also benefited from extra bass reach. But that came a bit later.


That this meatier fullness could coexist with an apparently improved tweeter—perhaps this driver wasn't upgraded at all and merely seemed that way because of the general house cleaning the ABR had done?—was a lovely surprise. Too often we're used to better purer treble being accompanied by a concomitant bleaching in the lower ranges. Not here. Spinning up my favourite club maestro Mercan Dede with his first Dünya album showed how the guttural growls of the didgeridoo had rather more snarl and how the poignant drums hit like clean projectiles without the usual impact debris. These now were primary benefits of lower more powerful bass. Unlike big drums going pow(ow)—with the italicized content in the brackets a small echo—they now went poppp. I put the closer in triplicate to indicate how sharp and sudden and dry of an ending they made. Removing the usual splash of clattering mud after low bass hits did, as always, translate as both drier and lighter. As haters of cheap subwoofers like early walkabout Sunfire boxes know full well, bass distortion equals higher perceived loudness. As owners of properly engineered equipment isolation racks know, bleeding out mechanical resonances makes your bass sound lighter and tighter whilst at the same time increasing in pitch definition and contour. That duality of less and more (less apparent impact from less mud, more clarity also from less mud) played here too. It demonstrated how one can be used to a certain amount of raw distortion mixed into things and mistake it for something else.


Without a close front wall to capture some of my ABR waves, I didn't really benefit from increased bass surface as such. To get the scaled-up punch and shoving air displacement of big woofers requires actual big woofers, never mind any nearfield setup. After all, premium headphones like Audeze will do 25Hz bass with real power. Yet there's no comparison to the full-body wave massage of a 15" or 18" woofer. Where Amphion's passive radiator in this speaker ups quantity is on raw reach. The improvements in quality are better damping of the main driver; and from that better articulation. That articulation works wholesale far above just the bass. So much for the outcome of my first A/B against the Helium 510.