THE CONCEPT
Inspired by the nostalgic, lo-fi auditory characteristics of vintage loudspeakers used in festivals and public announcements, this project is a real-time audio processing patch designed to replicate the specific “weird delay and echo” of mid-century PA systems. The system functions as a digital mimic, capturing live vocal input and transforming it through a feedback-driven performance engine to provide the spatial sense and characteristic imbalance of antique audio hardware.
THE ENGINEERING
I architected the signal flow within Pure Data (Pd), organizing the patch into three distinct functional modules: a Trigger Section, a Performance Engine, and an Output Section. The system utilizes the adc~ object to capture high-fidelity voice input, which is simultaneously written to a delaybuffer and monitored by a sigmund~ analyzer. When the input amplitude crosses a calibrated threshold ($>70$), it activates a performance sequence that reads the buffer using delread4~ at randomized intervals to simulate the unstable timing of vintage circuits.
To achieve the “loudspeaker” aesthetic, I engineered a feedback loop that throws processed signals back into the buffer after applying a tanh expression for signal saturation. I also implemented a custom panner that maintains the intentional channel imbalance observed in older, poorly calibrated hardware, forcing a spatial bias toward one side of the stereo field. The final output is regulated through low-pass and high-pass filters (lop~ / hip~) to match the restricted frequency response of traditional loudspeaker horns.
TECH STACK
Audio Core: Pure Data (Pd) / Plug Data.
Signal Analysis: sigmund~ (real-time pitch and amplitude tracking).
Signal Processing: Hyperbolic Tangent Saturation (tanh), Sample-and-Hold Logic.
Time-Domain Effects: Variable-speed delay buffers (delread4~, delwrite~).
Filtering: Low-pass (lop~) and High-pass (hip~) spectral shaping
Symmetry & Control: Randomized LSTM-style triggers, phasor~ driven sample-and-hold modules.
Acoustics: Spatial Asymmetry & Recursive Feedback Loops