Velvet Noise

Stereo Widener

Most stereo wideners fake it. They shift phase, add delays, or manipulate frequency bands in ways that fall apart on headphones, in mono, or at the mastering stage. Velvet Noise takes a different approach, grounded in acoustic research into how the human brain actually perceives space.

At its core is a technique called velvet-noise decorrelation. Rather than treating the left and right channels as a single image to stretch, it makes the two channels genuinely less similar to each other in a way that mirrors how real acoustic spaces naturally scatter sound. The result is a wider stereo image that holds together in mono, survives the mix, and doesn’t pull the center apart.

A single knob controls how much widening is applied. Full counterclockwise is your original signal, untouched. Clockwise adds width progressively, blending the processed signal in with the dry. Maximum settings apply subtle modulation for extreme separation.

No phase weirdness, no pumping, and minimal latency.

Velvet Noise can process a mono or stereo inputs. 

For the nerds:

Velvet Noise uses a Spin Semiconductor FV-1 DSP chip to perform a velvet-noise decorrelation algorithm. This method was developed by researchers at Aalto University and first published in 2017.

Velvet noise is a sparse sequence of tiny random impulses, each either positive or negative, spaced and timed so they’re individually inaudible but collectively push the left and right channels apart in correlation terms. The chip generates independent random sequences for each channel and samples little pieces of left and right, differentiating left from right without obvious pitch or comb-filtering artifacts. The width knob performs a wet/dry blend between the original signal and the decorrelated version.

At moderate settings, the processing adds air and space while keeping transients clean. At full width, the channels are maximally decorrelated — as far apart as the algorithm can push them. Maximum decorrelation using velvet noise is achieved around 50% on the knob. At higher knob settings we also add motion by modulating the twin delay lines. It’s a very subtle modulation but you can hear it, especially if you input lots of harmonic content from things like drive pedals.