You downloaded a free EQ app hoping to change how the whole Mac sounds, dragged a few sliders, and only one app responded. Spotify got a little brighter, but the video playing in Safari right next to it stayed exactly the same. That gap, between an equalizer and a system-wide equalizer, is worth understanding before you try app number four hoping it finally reaches everything at once.
Why most free EQ tools stop at one app
Most of the free EQ tools people find are built into a single app. Music, Spotify and a handful of players ship their own equalizer, and it works by processing audio before that app hands it off to macOS. Once the sound leaves the app, it goes straight into Core Audio, which mixes every app’s output together and routes the result to your speakers or headphones. There’s no EQ stage in that shared path by default. Nothing shapes tone after the apps are done talking, because macOS was never designed to.
That’s also why the free tools that do work system-wide ask for an administrator password and restart your Mac’s audio service the moment you install them. To touch audio after it’s been mixed, a tool has to sit inside that Core Audio path itself, usually as a HAL driver, which is a piece of software the operating system treats as an audio device. Building and maintaining a driver like that is a meaningfully bigger undertaking than shipping an in-app slider, which is part of why genuinely free, actively maintained, system-wide options are rarer than app-level ones.
The free options that already exist
If your actual problem is a single loud or dull-sounding app, the free option is already sitting in that app’s settings, no install required. Music, Spotify, and most other players have owned an equalizer for years, and it costs nothing to use.
macOS itself ships Audio MIDI Setup, which lets you build aggregate or multi-output devices. People sometimes reach for it expecting an EQ, and it’s worth saying plainly: it doesn’t have one. It routes audio between devices; it doesn’t shape tone at all.
For something that actually reaches every app at once, eqMac is the best-known free option, and it’s open source. It works the way any driver-based tool does: it installs as an audio device, so it needs that same admin password and restart. Being free and community-maintained is a real trade-off, not just a price point — support for new macOS releases and new features moves at whatever pace the maintainers have time for, which can lag behind a paid product with a team behind it.
Above that sit paid all-in-one apps — Boom and Sound Control are the ones people mention most — that add loudness normalization, more bands, and polish in exchange for a subscription or one-time fee. ZonaReq sits in that same category, with a free tier underneath it rather than a trial that expires.
Doing it with ZonaReq
ZonaReq’s free tier is a real system-wide equalizer, not a demo: a 3-band EQ and five presets, applied to every app through the same HAL driver approach described above, with no time limit on the EQ itself.
- Install ZonaReq and approve the driver installation, which needs an administrator password. It restarts the Mac’s audio service, so apps that were already playing sound need to be reopened afterward.
- Pick your real output device — speakers, headphones or AirPods — in the main panel, then adjust the three free bands or apply one of the five included presets.
- If three bands feel too broad, the difference is the same one the curve above shows: Pro unlocks the full 10-band parametric with seven filter types and the rest of the 29 presets, so you can move one narrow range without dragging its neighbors along.
- Pro also adds what the free tier doesn’t touch at all — per-application volume, the spectrum analyzer, reverb, spatial audio, and the AU plugin host. It runs 4.99 USD monthly, 29 USD yearly, or 59 USD as a one-time lifetime purchase, billed in pesos for Mexican visitors.
What driver-based tools all require, free or not
One thing applies to every driver-based equalizer, free or paid, ZonaReq included: installing it touches how your Mac routes audio at a low level, so it needs an admin password and a restart of the audio service, and whatever was already playing needs to be reopened. That’s not a rough edge specific to one app — it’s the cost of sitting where a system-wide tool has to sit. If your actual need is making one app in particular sound better, the equalizer already built into that app is free, asks for nothing, and touches nothing else on your Mac. Reach for a system-wide tool when the problem is genuinely system-wide.