HakenAudio Slim21: Microscopic Expression in a Portable Powerhouse

The Haken Slim21 arrives as a highly portable iteration of the legendary Continuum, promising the same depth of expression in a form factor that weighs just 3.5 pounds. In this official walkthrough, Josh Madoff introduces the Slim21 as a standalone synthesizer, a highly sensitive MPE MIDI controller, and a robust audio processor. The device is designed to fit into a tote bag or backpack, making it accessible for both studio and live contexts without sacrificing the expressive power that Haken instruments are known for.

What sets the Slim21 apart is its ability to serve multiple roles: it’s a self-contained synth with over 500 presets, a controller for external hardware and software, and an audio processor with digital input capabilities. This versatility is not just a checklist feature—it’s core to the Slim21’s workflow philosophy. The video makes it clear that the Slim21 is engineered for musicians who demand both portability and uncompromising expressiveness, whether they’re leading a DAWless rig or integrating into a traditional studio setup.

At the heart of the Slim21 is a playing surface that leverages up to 12 finely tuned Hall Effect sensors per finger, each sampled by a 14-bit AD converter. This architecture delivers a level of pitch and dynamic sensitivity that far exceeds standard MIDI controllers, capturing hundreds of thousands of samples in a single long note. The result is a surface so responsive that it’s physically impossible to repeat the exact same gesture twice, making every performance inherently unique.

The tactile experience is further enhanced by a layer of piano springs beneath the surface, providing continuous physical feedback as you press and release. This combination of microscopic accuracy and mechanical resistance enables orchestral-level dynamics and nuanced expression. The video demonstrates how even the most basic sine wave preset becomes a canvas for subtle shifts in pitch, volume, and timbre, all mapped to finger position and pressure. It’s a workflow that rewards both precision and experimentation.

The Slim21’s sonic heart is the EaganMatrix, a sound engine designed to form a feedback loop between performer, instrument, and sound. With over 500 internal presets, the EaganMatrix is more than a patch library—it’s a programmable ecosystem where each preset defines complex interactions between human input and sound generation. Every patch point in the matrix can be mapped from zero to full human control, allowing for granular modulation of pitch, timbre, and dynamics.

The video showcases how the EaganMatrix leverages the Slim21’s multidimensional sensitivity, making every note a unique event in pitch, tone, and articulation. Features like touch areas, macro controls, and pedal assignments are demonstrated, highlighting the flexibility to assign parameters such as delay, filter, or sustenuto to various inputs. The sustain and sostenuto implementation is particularly notable: not only can you hold and dynamically control notes with your feet, but you can also layer multiple sustained regions and continue playing on top, all with independent dynamics.

This architecture blurs the line between acoustic and electronic instruments, enabling workflows that are as suitable for intricate solo performances as they are for complex studio layering. The EaganMatrix’s deep integration with the Slim21’s surface and external controllers makes it a true chameleon in any creative environment.

The Slim21 is built for seamless integration with both hardware and software synthesizers, extending its expressive capabilities far beyond its internal engine. The video demonstrates control over MPE-compatible hardware like the Oberheim OBX8, where pitch, filter, and volume can be mapped to finger axes and pressure, and sustenuto and tri-octave pedal functions translate directly to the external synth. This level of control is equally at home with software instruments such as Cherry Audio’s Miniverse and DC-0106, where MPE mappings allow for nuanced manipulation of filter, cutoff, and oscillator detuning.

Notably, the Slim21 doesn’t limit itself to MPE environments. For non-MPE synths like the Dave Smith Instruments Prophet 08, users can assign custom MIDI CCs to pressure, y-axis, and pedals, enabling expressive control even on vintage or less flexible hardware. The ability to set pitch bend ranges, reverse CCs, and configure assignments directly from the device or via the Haken Editor underscores the Slim21’s commitment to workflow flexibility.

Beyond MIDI, the Slim21’s audio processing capabilities are highlighted with presets like the harmonic resonator, where each finger can independently control resonator parameters. This positions the Slim21 not just as a controller or synth, but as a central hub for creative routing in hybrid setups, including Eurorack and effects integration via the Haken CVC.