The musician's Mac setup: DAW vs reference-track volume

To compare your mix against a reference track honestly on a Mac, the two have to be the same loudness — but your unmastered DAW mix is always quieter than a released track, and the system volume moves both at once. The fix is to give your DAW and your reference player their own independent volume, level-match them by ear, then A/B between them without touching either fader. macOS won't do that on its own; a per-app volume mixer will.

Every producer hits this the first time they pull a commercial song into the session to check their low end or their vocal level. The reference is loud, confident, finished. Your mix, sitting next to it in the DAW, sounds thin and small — not because it's worse, but because it's louder on the reference by 6, 10, sometimes 15 dB. Louder always sounds better for a second. If you don't level-match before you compare, you'll chase a loudness difference and make bad mix decisions all night.

Why the reference wins before you've made a single move

Two things stack against your mix. First, the reference is mastered: it's been through a limiter and turned up to a competitive level, so it has almost no headroom. Your in-progress mix deliberately keeps headroom and has no final limiter, so at the same fader position it plays quieter. Second, if your reference lives in a streaming app, that app applies its own loudness normalization on playback — Spotify targets around -14 LUFS, Apple Music around -16 LUFS — which changes the playback gain out from under you depending on where the track came from.

The result is that raw fader numbers lie. The only reliable way to A/B is to trim one source until the two sound equally loud to your ears, then switch between them fast enough that your ear holds the memory. That demand — two independent levels, matched once, toggled instantly — is exactly what a single master volume can't give you.

What macOS gives you, and where it stops

macOS has one output level. Turn it down and your DAW and your reference player drop together, which keeps them mismatched at every setting. There's no native panel to say "reference player at 60%, DAW at 100%." So producers reach for workarounds, and each has a real limit.

Reference plugins that load a track onto your master bus and gain-match it are excellent, and if all your references are audio files, use one. But plenty of producers keep their references in Spotify, Apple Music, or YouTube — playlists they've built over years, tracks they can't legally drop into a session. For those, the reference lives in a separate app, and balancing a separate app against your DAW is an operating-system problem, not a plugin problem.

The clean setup: two faders, matched once

Here's the workflow that keeps the comparison honest. Set your DAW's output where your monitoring gain wants it and leave it. Then treat the reference player as a second channel you trim independently: pull it down until a loud, familiar reference sounds the same volume as your mix. Now switching between them is a true, level-matched A/B — any difference you hear is the mix, not the loudness.

The only piece macOS is missing is the second, independent fader for the reference app that you can reach without leaving the DAW. That's what a per-app volume mixer adds. It sits at the system audio layer and gives every running app — your DAW, Spotify, a browser, Apple Music — its own level in one place. You can read the deeper background on how to control individual app volume on a Mac if you want the full picture of why the OS works this way.

Why the keyboard is the part that matters for producers

A reference check isn't a one-time move — you do it dozens of times a session, on every element you're unsure about. If matching and toggling means moving to the menu bar, clicking, finding a row, and dragging a slider every time, you'll stop doing it, which is the worst outcome for your mixes. The comparison has to be as fast as a plugin bypass.

That's Fader's bet: the fastest controller you own is the keyboard already under your hands. You map your reference player and your DAW to keyboard columns, hit a toggle hotkey, and ride their levels with letter keys without leaving the session — or bind a mute key so "silence the reference, hear only my mix" is one keystroke, and back again the next. You set the match once and switch between mix and reference at the speed you actually work. If Spotify is your reference source specifically, the same idea covers controlling Spotify's volume separately on Mac.

Where the free and paid options land

You don't have to take my word that this needs paid software, so here's the honest lay of the land. Background Music is free and open source, and it does give each app its own volume — a real option if you're on a budget and don't mind that it hasn't kept pace with recent macOS releases and needs a system extension approval to install. SoundSource from Rogue Amoeba is the deep, polished tool: per-app volume plus per-app EQ and effects, driven from a menu-bar panel, at $49 one-time. Fader is the keyboard-first take at $19.99 one-time with a 3-day trial — narrower than SoundSource on effects, faster to reach the fader for the ride-it-constantly moves a reference check demands.

None of these is a mastering tool, and none replaces a proper reference plugin for imported files. They solve the specific gap macOS leaves: holding your DAW and a live reference app at two independent, matched levels you can flip between instantly.

Bottom line

An honest A/B starts with matched loudness, and your unmastered mix will always lose that match to a released reference unless you correct for it. If your references are audio files, a gain-matched reference plugin on the master bus is the tidiest answer. If they live in a streaming app, you need per-app volume the OS doesn't ship — set the reference and the DAW to matched levels once and toggle between them. If reaching that toggle in a keystroke, mid-session, is what keeps you actually doing the comparison, that's exactly what Fader is built for.