Subwoofers — Stenheim Alumine Sub

The Alumine Sub is an active subwoofer from Stenheim, the Swiss loudspeaker maker, shown under this name at High End Munich 2025 and now sold as the Alumine S10, presented in that form at High End Vienna 2026. It is designed for the Alumine range and aimed especially at owners of the Alumine Two and Two.Five, as well as at larger rooms, and it can also be used with the Alumine Three and Five, with speakers from other brands and in home cinema systems.

Key specs that matter

Two 26 cm high-excursion drivers work in an isobaric arrangement within a sealed enclosure. The built-in amplifier delivers 1200 W. Frequency response is 20 Hz to 100 Hz. The cabinet is made entirely of aluminium with three independent internal chambers. Inputs are XLR or high-level, selected by a switch, RCA, Toslink, coaxial S/PDIF, AES on XLR and an RJ45 Ethernet port. Outputs are XLR, either passed through or filtered, RCA pass-through and Toslink pass-through. The subwoofer measures 32 cm wide, 34.2 cm high and 43 cm deep without spikes and weighs 44.5 kg. Standard finishes are Light Grey and Dark Grey with black front and rear panels, and Full Black, Ivory and Mocca are available as custom options. Stenheim gives three years of warranty on the electronics and five years on the passive parts.

Engineering and use context

In an isobaric layout one driver sits behind the other and both move a shared trapped volume, which lets the pair behave like a single driver needing only half the cabinet volume. Combined with a sealed alignment, this keeps the enclosure compact for two large drivers. The three internal chambers separate the drivers and electronics inside the aluminium cabinet. A DSP handles crossover frequency, gain and phase, which are adjusted through a mobile app or a browser page over a wired Ethernet connection, and the firmware can be updated. Presets for the Alumine models are stored, and the low-pass filter is adjustable. Digital inputs let the subwoofer receive a signal directly from a digital source, and it supports UPnP and Roon for streaming. Several units can be daisy-chained through the pass-through outputs.

Pairing

The Alumine S10 is intended mainly for the Alumine Two and Two.Five, and extends the bass of the Alumine Two well below its own limit. The XLR and high-level inputs connect to a preamplifier or amplifier, and the digital inputs to a streamer or transport.

Alternatives

Stenheim currently offers no other subwoofer.