EQ everything your Mac plays.

EQBase is a system-wide equalizer for macOS. It is a full app with its own window for the deeper work, plus a menu-bar popover for quick changes, and it processes everything your Mac plays in real time (browser video, calls, games, every app), from a simple 10-band graphic EQ up to a 24-band parametric one with dynamic and linear-phase filters. It adds zero samples of latency to the direct signal, and when every control is flat the processing chain is bit-perfect: samples leave exactly as they came in. Exactly two features add latency, both opt-in and both shown in the app's own latency readout: the true-peak limiter (2 ms of lookahead) and linear-phase EQ mode (about 43 ms at 48 kHz). Correction profiles for 6,000+ headphone models are built in, from the AutoEQ project. EQBase runs on macOS 14.4 (Sonoma) or later on both Apple silicon and Intel, sets up without installing a driver or asking for an administrator password, and supports sample rates from 44.1 to 192 kHz end to end. Beyond the equalizer it also does the things macOS leaves out: per-app volume, one-click recording of system audio, room measurement with automatic correction, audio routing, and working volume keys on outputs where macOS greys them out. The free tier has no time limit; Pro starts at $4.99 a month.

A system-wide equalizer for Mac changes the tone of everything the Mac plays, from Safari and Spotify to calls and games, rather than one player's sound. macOS has no such equalizer built in; the Music app's EQ reaches only Music. What it adjusts is loudness by frequency: each band has a center frequency, a gain in decibels and a width (Q), and a preamp lowers the whole signal so boosts have room instead of clipping. A 10-band graphic EQ fixes its bands an octave apart, from 31 Hz to 16 kHz, and leaves you the gains; a parametric EQ lets you set every band's frequency, gain, width and filter shape, which is what an exact headphone or room correction needs. In EQBase the 10-band EQ and its preamp are free, and Pro adds a 24-band parametric EQ with dynamic and linear-phase filters. The same chain also sets volume and balance per output device, loudness compensation for quiet listening, and a separate correction layer for headphones and rooms.

Yes, on the free tier, in one click from the menu bar. macOS itself has no way to save its own audio, and the common workarounds either cost money or route everything through a virtual output device, which then takes your volume control with it. EQBase already has the stream, so it just writes it: the finished post-limiter master, exactly what your DAC is handed, to MP3, AAC, ALAC, FLAC, WAV or AIFF. Your output device and volume keep working normally the whole time, and nothing is sent anywhere; the file goes where you pointed the save panel.

Yes, on the free tier. When an output reports a fixed level (most HDMI and optical connections, and plenty of USB interfaces) macOS has nothing to change, so it greys the volume keys out and you are left reaching for the monitor's own menu. Turn the option on in EQBase and the keys drive EQBase's volume instead, with an on-screen HUD and no system bezel. It is off until you enable it, macOS asks for Accessibility permission at that click, and it only ever arms on outputs whose keys were already dead, so a device with real hardware volume is never intercepted.

Yes, with Pro. EQBase plays a frequency sweep through your speakers, captures it with a microphone (a measurement mic if you have one, the built-in one if you do not), averages a few takes, and fits a parametric correction to what it found. It draws the measurement, the target curve and the fitted result on one plot, plus a decay map showing which frequencies ring on after the music stops, so you can see the reasoning rather than take it on faith. The result lands in EQBase's correction layer, underneath whatever curve you have set yourself, so the two do not overwrite each other.

Not to run the equalizer. EQBase reads the mix your Mac is already playing and mutes the original at the same instant, so there is no driver, no administrator password and no restart. The one thing setup asks for is permission to record this computer's audio, which is how macOS classes reading system audio. Two optional features do still use a small user-space Core Audio driver (never a kernel extension), and EQBase offers to install it at the moment you turn one on: Audiophile mode, which reads the samples untouched, and Pro routing, which publishes a virtual microphone other apps can select. Neither is part of a normal setup.

No, and the app proves it. With every control flat or bypassed the processing chain is bit-perfect: samples leave exactly as they came in, verified continuously and shown live in the app. Flat isn't "almost transparent," it's mathematically identical. How the audio reaches that chain is a separate question, and EQBase is specific about it: in the default mode macOS hands over a converted copy of the system mix, which we measured and will not call bit-perfect. Audiophile mode installs the driver and reads the samples untouched, measured at 100% identical, and the app tells you which path is live rather than making you assume.

Yes. Your license is validated online now and then, and a subscription keeps working for 14 days without any connection. A lifetime license works offline indefinitely. A flaky network never turns your sound off.

The core app is free with no time limit, so you can take your time deciding. If you upgrade and change your mind, every purchase has a no-questions 14-day refund policy.

macOS 14.4 (Sonoma) or later, on Apple silicon and Intel, one universal, notarized app. Sample rates from 44.1 to 192 kHz are supported end to end.