ESP-L1 by ESP Audio – Limiter Plugin VST3

ESP-L1 is a time-domain brick-wall limiter with a full analysis front end. Nothing it does to your signal is hidden from you.

Detection is linked-stereo peak, taken across both channels sample by sample, so the stereo image never shifts under gain reduction. Attack is instantaneous; release is exponential, and its coefficient is derived from the host sample rate, so 100 ms stays 100 ms whether the session runs at 44.1 or 96 kHz.

The display is the point of this plugin. A scrolling oscilloscope holds roughly three seconds of audio in a 131,072-sample ring buffer and draws min/max per pixel, so one clipped sample is still visible. Pre and post are overlaid, with the threshold as a dashed line. On top of that, a 2048-point Hann-windowed FFT runs on both the pre- and post-limiter signal across a logarithmic 20 Hz to 20 kHz axis, which makes it plain when limiting starts eating the low end. A stereo VU pair with analogue-style decay and a gain-reduction meter finish the picture, and FREEZE locks every display at once when you want a closer look.

Three controls, no menus: Threshold (-60 to 0 dB), Release (10 to 1000 ms, log-scaled) and Out Gain (-12 to +12 dB). Three vintage themes cycled from one button: AMBER warm tube, PHOSPHOR green CRT, STEEL dark rack.

Written in C++17 with JUCE. Free, and the source is on GitHub.