Expert Sleepers Disting EX: Quadraphonic Mixer Mode – Spatial Audio in Eurorack

The video opens with Expert Sleepers presenting the disting EX’s new Quadraphonic Mixer mode, a conceptually straightforward but rarely seen feature in Eurorack. Here, the disting EX becomes a six-input, four-output mixer tailored for quadraphonic spatial audio—a format with roots in early Buchla systems, where four speakers are arranged in a square around the listener. Unlike modern surround setups that emphasise front-back separation, this classic quad approach treats all four corners as equals, inviting more immersive and democratic spatialisation.

With four outputs mapped to front left, front right, rear left, and rear right, the module is designed for genuine quad listening—though, as the video notes, YouTube’s limitations mean the demonstration is rendered binaurally for headphone use. This sets the stage for a hands-on exploration of spatial mixing, with the promise of real-time panning and movement across a virtual soundfield.

At the core of the Quadraphonic Mixer are controls for gain, coordinate systems, and CV mapping, all of which shape how sounds traverse the spatial field. Each of the six input channels offers independent gain, allowing precise balancing of sources before they’re sent into the quad environment. The video demonstrates this with a simple noise source, making it easy to hear panning and movement.

The coordinate system is a key feature, offering both rectangular (X/Y) and polar (angle/radius) modes. Rectangular coordinates let you move sounds left-right and front-back, ideal for joystick control or CV automation. Polar coordinates, on the other hand, allow you to spin a sound around a central point by adjusting angle and radius—mathematically elegant and musically expressive. The trade-off between using inputs for audio versus CV is highlighted, with suggestions to use MIDI or I2C for more complex control without sacrificing audio channels.

The disting EX Quadraphonic Mixer introduces the concept of spinners—programmable movement paths for each channel. Each input can be assigned a spinner, with controls for spin radius, rate, and phase. This enables everything from simple circular motion to more complex, layered spatial choreography, where multiple sounds can chase each other around the room or move in offset patterns.

The video points out that channels can share spinners, allowing for phase-offset movement—imagine two sounds orbiting the listener in quadrature. With just a single sound source in the demo, the full effect isn’t realised, but the potential for intricate spatial layering is clear. The spinner’s rate can be dialled up for rapid movement or reversed for counter-rotation, offering a wide palette of dynamic motion for live or generative patches.

Beyond spatial movement, the Quadraphonic Mixer provides a suite of utility controls to adapt to real-world setups. Overall gain lets you set the master level, while separate front and rear gain controls help balance mismatched speaker pairs—handy if your quad rig is cobbled together from two stereo PAs. Tone controls for both front and rear outputs allow you to compensate for differences in speaker voicing or to deliberately sculpt the soundfield.

A saturation option is included, echoing features from other disting EX algorithms. When enabled, it prevents harsh digital clipping by gently crushing the signal as levels rise, resulting in a more musically pleasing overdrive. This is on by default, ensuring the mixer remains forgiving even in the heat of a spatially adventurous performance.