The Stenheim Alumine 2SE Loudspeaker
By Roy Gregory
Even the sight of a speaker like Stenheim’s Alumine 2 will strike many a reader as strange, so rare has the two-way stand-mounted loudspeaker become. Yet not so long ago, this was the most popular speaker size and format on the market – with good reason. Those same reasons help explain why, when Stenheim wanted a ‘proof of concept’ product to examine their acoustic and mechanical approach, they started with this compact stand-mount, rather than some massive flagship design. In Stenheim’s case, the rest is, as they say, history, a range of larger models garnering plaudits and positive reviews right across the international audio scene. Yet to understand just why it all started with the A2 – and why you should take the A2 more seriously than first impressions suggest, perhaps a short trip down memory lane is in order.
These days, stand-mounted loudspeakers seem like an endangered species, swamped and strangled by the weed-like spread of slim, floorstanders, speakers that tick the style and quantity boxes as emphatically as they so often miss the quality one. Aside from the resolutely retro buyers who insist that their purchases look as old as the technology they employ (a group who are single-handedly consuming the World’s remaining stocks of Teak veneer) serious stand-mounts have been in decline since the heady days of the Magico Mini. Every so often somebody will launch a speaker that’s as small as it is ludicrously over-priced, but that’s got more to do with opportunistic marketing strategies and grabbing attention than it does with delivering real musical performance and value. Which is a shame, because there are sound musical and sonic reasons why stand-mounts used to rule the roost – and those performance realities haven’t changed.
The trick with stand-mounted speakers is to balance their virtues and minimise their weaknesses. Okay – so that’s no different to any other loudspeaker, but the physical constraints of stand-mounting (unless you are going to talk outliers like the massive Spendor BC3/Classic 100) afford the designer certain inherent advantages. Limited cabinet size imposes a practical limit on bandwidth – although the mid-80s obsession with getting ever more bass out of even smaller boxes, at the expense of crippling impedance characteristics and sensitivity rates as one of audio’s more spectacular wrong turns. Take a bow the Celestion SL6/600 and the Acoustic Energy AE1. Back in the real world, the magic numbers are 50 Hz and less than two cubic feet. The former delivers enough bandwidth to be musically satisfying (if not utterly convincing) while the latter allows for manageable cabinet dimensions. It’s no surprise that classic designs like the Spendor BC1, Rogers LS7 and the Mission 770 all conform to that outline brief, although back in the day a -3dB point nearer 60Hz wasn’t unusual, perhaps reflecting the limited load tolerance of contemporary amplifiers and the limited power of the magnets used in drive-unit motors. But the really key point about the bandwidth is that it can be readily covered by a two-way design, making for a far simpler and less ‘subtractive’ crossover. Combine that potential for inherent simplicity with the easier task of balancing a narrower bandwidth and the chances of getting it right improve exponentially. In musical terms, the two cubic-foot/two-way is very much a sweet spot in speaker design – and it very definitely still is!