OERL

OERL (Open Equalizer Research Lab) processes everything your Mac plays, from music and videos to calls, before it reaches your headphones or speakers. It lives in the menu bar, runs entirely on your Mac, and never records or sends audio anywhere.

HEADPHONE CORRECTION • Load your headphone's AutoEq ParametricEQ.txt profile • Bypass (A/B) compares processed and original sound instantly, with matched latency

MUSICAL EQ • Ten bands named for what you hear: Sub-bass, Bass, Warmth, Mud, Mids, Definition, Presence, Brightness, Brilliance and Air • See which instruments live in each band, and Solo a band to hear it on its own • 30 presets, from Vocal clarity and Less harsh to Jazz, Metal, K-pop and Luk thung

PSYCHOACOUSTIC FFT EQ • 16 to 40 bands evenly spaced on the Mel, Bark or ERB auditory scales • Linear-phase STFT processing • 20 curves, including ISO 226 equal-loudness compensation and IEC 61672 A-weighting, or load an AutoEq GraphicEQ or CSV curve

NATURAL HEADPHONE LISTENING • Crossfeed and a subtle room effect move the sound out of your head • ISO 226 loudness compensation keeps bass and air when you listen quietly • A true-peak limiter with 4x oversampling prevents clipping

LIGHTWEIGHT AND SAFE • About 1.6 ms added latency and around 2% CPU on Apple silicon • Quit OERL and audio goes straight back to your device

OERL needs the System Audio Recording permission to process sound. Audio is handled in real time in memory only: nothing is recorded, stored or transmitted, and the app collects no data.

Discovery signals