Stenheim Alumine loudspeaker
The sound of the Stenheim Alumine loudspeakerits openness, transparency, and freedom from temporal distortions, not to mention its good bass extension for such a small enclosurereminded me at once of my favorite small loudspeaker from the late 1980s, the Acoustic Energy AE1. On reflection, the comparison is extraordinary: The two products are as different as night and day, the AE1 being a wooden loudspeaker with a metal-cone woofer, the Alumine a metal loudspeaker with a pulp-cone woofer. I suppose one can skin a catfish by moving the knife or by moving the fish.
Yet from there, similarities win the day. Both products originate from the school of thought that says a loudspeaker enclosure should be as inert as possible (as opposed to the school that permits some panel resonances). Both designs employ front-panel reflex ports (one in the Stenheim, two in the AE). Both use decidedly nonminimalist crossover networks. Both are intended for use on purpose-built aluminum stands.
And both speakers are, or were, noted for being expensive, if not quite rapaciously so. In 1988, at a time when my loudspeaker budget could barely stretch to four figures, the Acoustic Energy AE1swhich I covetedwere out of reach at $1500/pair. In 2012, at a time when I continue to be delighted by my Audio Note AN-E SPe/HE speakers ($8475/pair), the Stenheim Alumines are likewise more expensive by half: $12,795/pair. Plus ça change . . .
Stenheim was founded in Switzerland by four former employees of Goldmund SA, the Swiss high-end audio company known for their perfectionist-quality loudspeakers, electronics, and source components. The Alumine is Stenheim's first commercial productand I'm told that their startup costs were considerable, given that the Alumine's enclosure panels, made by the Swiss branch of an international high-tech machining firm, are specified perfect to within 0.01mm.
The Alumine's high-frequency driver, made in Norway by SEAS, is built around a 1" fabric-dome diaphragm with a half-roll surround. That driver fires from a shallow and slightly compliant elliptical waveguide that measures a little over 3" on its largest dimension. The mid/woofer, made by the French company PHL, has a 5" cellulose-fiber cone (it appears to be coated on both sides), and a 1.75" dustcap of carbon fiber. Also featured are a sturdy cast-aluminum frame and an S-shaped (in cross section) surround of moderately soft rubber, intended to restrict cone excursions to the most linear portion of the driver's range.
Both of the Alumine's drivers are hardwired to a sizable crossover network that comprises four chunky air-core inductors, various M-Cap polypropylene capacitors, and a surprisingly large number of Dale metal-film resistors, all on a PCB just a little bit smaller than the inside-top surface to which it's fastened.
The plastic bass-reflex loading tube, which is cemented to the baffle, is 3.25" long, with a 2" diameter and a flared port. The baffle is the only cabinet wall whose inner surface is undamped; bituminous pads and thick sheets of sound-absorbent material are applied to all the rest. Only one pair of input terminals is provided, suggesting that the designers are not fond of biwiring (cf Wilson Audio Specialties and a number of other speaker manufacturers who feel similarly about the multiway speakers they make).
Then there's the real star of the Alumine show: the aluminum-alloy enclosure. Its individual panels, which indeed seem to be made and finished with the utmost precision, are 0.6" thick. Those metal sheets are held together by more than 60 concealed machine screws per cabinetamong the principals of Stenheim, all of whom are in their 30s, is a former watchmakerwith silicone gasket material, sparingly applied, to enhance the seal.
The companion stand is about 28.75" tall when assembled. Its pillar comprises two concentric aluminum-alloy tubes of rectangular cross-section, and its upper and lower surfaces are, like the panels of the speaker cabinet itself, machined from aluminum alloy to a thickness of 0.6". Integral to the latter are generously sized channels that lead from the stand's inner channel to discreet openings at the rear, both top and bottom; thus the user can route the speaker cable from the amp into the stand's lower support, up through the pillar, and out through the stand's upper support, where it can connect easily to the speaker's gold-plated WBT terminals.
The upper support of the Alumine stand is machined with three circular recesses, each measuring about 0.4" in diameter: one each at the rearmost corners, and one centered near the front edge. These correspond to similar, but smaller and shallower, recesses in the bottom surface of the speaker enclosure, allowing for a unique interface between the two components: a trio of 0.4"-diameter stainless-steel ball bearings. Fully set up, there is a very slight gap between the top of the stand and the bottom of the speakerand the latter is unambiguously stable.
Setup and installation
Products that are poorly made are a drag to set up. Products whose shipping materials are indifferently designed are a drag to set up. The Stenheim Alumines were a delight to set up.
My review pair of Alumines arrived in two foam-lined flight case; another such case contained the disassembled stands, which were very easy to put together, owing to the clean, precise fit between their parts and their fasteners. After fitting the four threaded feet to the stand's bottom plate and putting the three ball bearings in their recesses on the upper plate, I lowered the rather heavy (37.4 lbs) Alumine speaker into place, and felt a satisfying clunk as each ball and its corresponding recess lined up with one another and settled together perfectly: The cabinet's front and rear edges were now precisely aligned with the front and rear edges of the stand. I love the Swiss.
After my recent experience with the Sonus Faber Guarneri Evolution loudspeakers (see my review in the January issue), I wondered if there was anything to gain by leveling the tops of the Alumine cabinets with one another; surely there was nothing to lose. That was easy to do, using a ball-end hex key from above to adjust the stands' feet. Working thus, it was also easy to stabilize the stands against my listening room's hardwood floorsomething I recheck and readjust often for all loudspeakers, to compensate for the settling of the speaker's weight and the seasonal expansion and contraction of the wooden floor.