How I reverse-engineered a commercial spatial audio effect
How I reverse engineered a commercial spatial audio effect
Frustrated by the lack of a simple spatial audio tool for Linux, the author set out to recreate a commercial effect that makes music sound farther away and less 'on the ear.' After initial attempts with HRTFs and an LLM hit a wall, they took a different approach: capturing the filter's impulse responses by playing test signals through the program on a friend's laptop. The extracted filters, when loaded into Saq, finally reproduced the out-of-head placement they had been chasing.
The LLM began talking about things like 'perceptual envelopment', 'late-field decorrelation', 'spectral diffusion' and 'diffuse spatial energy'. While I could hear that something was wrong, those descriptions didn't point to anything I could understand or use to improve the effect.