Loudspeakers

Although these are LS3/5A-centric, I used them with both Tannoy's Autograph Mini and JBL's 4321M small monitor to test Rogers' claim of compatibility with other speakers. So, stone me again – thanks to the adjustable gain, phase and LPF settings, you can, indeed, use the AB3a with other small loudspeakers.

Free 'N' Easy
If you are hoping that the AB3a will enable LS3/5As to 1) bang out Twisted Sister at 120dB, and 2) play Kodo drums with the same impact as via a quartet of 18in Hartley woofers, then you're in for a huge disappointment. On the other hand, if 'subtlety' is a virtue in your estimation, then the changes wrought by the AB3a will impress.

First, you must forget the AB1 ever existed. While I still get a kick out of mine, the AB3a is to the AB1 what a 4k OLED screen is to a 405-line black-and-white cathode-ray TV. The AB3a is everything you want from an active subwoofer bar the ability to loosen your home's foundations. It is not a kick-you-in-the-gut device for adding thrills to a home cinema.

Rather, you need to approach the AB3a expecting to free up the sound, if in ways that do not immediately spring to mind. Call them unintended consequences or, better still, unanticipated benefits. And what first made me realise this was the Nimbus Supercut of Miles Davis' Kind Of Blue [CBS 62066]. The difference between with AB3a and without revealed itself throughout the entire LP, in various ways. The first was a sense of greater openness, the second was enhanced stage depth, while a third benefit was the exposure of fine details with improved clarity.

As this LP is a trumpeter's creation, you'll be pleased to learn that the punch, extension, clarity and, yes, the sound of Miles' saliva, were a touch more vivid. Please bear in mind that the subwoofers were tuned to their least intrusive settings, such that I was wondering if they were even switched on. I couldn't see or feel any woofer movement when I removed the grilles from the AB3as to check.

Up Scale
To reassure myself, I cranked up the level just enough to hear an audible blub-blub-blub, so, yes, they were working. In my system, the crossover was set around 60-80Hz, phase to –60° and level two notches from the minimum (after having dialled in too much level just to hear them working).

Moving on to my definitive bass tester, The Band's eponymous second LP [Mobile Fidelity MFSL 1-419], the dry percussion from 'Up On Cripple Creek' gets me every time, along with the copious, melodic bass. But I repeat, without employing exaggerated level settings, the sound was distinctly more substantial. There's a snap to Levon Helm's drumming which is truly inimitable, while the entire song – no, make that the entire LP – has a richness that has always characterised The Band's sound.

It's a manifestation of the texture or atmosphere that you find in rural or unplugged blues recordings, including early Muddy Waters or Lightnin' Hopkins, and it's what modern roots music devotees aspire to for authenticity. You get a taste of it with LS3/5As on their own, while always suspecting that there's more waiting in the wings. Switch on the AB3a and it augments an LS3/5A au naturel (and the wee Tannoy) with just enough extra weight and warmth to expand the room-filling capability of the sound, with a discernible increase in scale.

Rising Stars
Two sublimely recorded, inherently warm albums such as The Band and Kind Of Blue are already in possession of a rich, reinforced bass, so I dug out something more bright and treble-oriented, though of equally sublime recording quality. Herb Alpert's open-reel tapes are exceptionally well-recorded (he owns his record label – doh!), and I couldn't resist a burst of The Beat Of The Brass [A&M AMC146], with its corny, staccato interpretation of The Mamas And Papas' 1961 hit song 'Monday Monday'.

Normally, such kitsch makes me wanna hurl, but I've warmed to it since owning it on reel-to-reel tape. Here the AB3a revealed another of its deft abilities by shifting the emphasis away from all the treble activity to the band's rhythm section. Again, the effect was subtle, but it was like adjusting the seasoning in a complex dish. The Rogers AB3a, then, is like another twist of the pepper mill, a scant hint of thyme. And that might be the difference between two Michelin stars… and three.

Hi-Fi News Verdict
When I raved about the AB1, I took a lot of stick for being too easy on it. That won't apply to the AB3a because it is what you make of it, thanks to the range of adjustments. I won't say the AB3a obviates the use of LS3/5As on their own, but they certainly augment bass and SPLs without affecting the purity of what's on top. This is one clever subwoofer: it does what it says on the box and looks great to boot.