If one app is too quiet even at full volume on a Mac, it's almost never the app itself. The usual causes are the app's own internal slider being turned down, your output Balance drifting off-center in Sound settings, Headphone Safety capping headphone volume, or the audio going to a quieter device than you think. Work through those four, and if the app just can't compete with everything else, the real fix is to keep it at 100% and turn the other apps down instead.
"It's maxed out and still too quiet" is one of the most common Mac audio complaints, and it's frustrating precisely because you've already done the obvious thing — pushed the volume all the way up. The system keys are at full, the app is at full, and it's still buried under everything else. The good news: there's a short list of real culprits, and each has a clean fix. Let's go through them in the order worth checking.
First, separate "absolute" quiet from "relative" quiet
There are two different problems that feel identical. In the first, the app is genuinely putting out a low signal — quiet in headphones, quiet on speakers, quiet on its own with nothing else playing. In the second, the app is actually fine, but it sounds quiet because a browser, a game, or a music app next to it is much louder. The fix for those two is completely different, so the fastest diagnostic is to play the quiet app alone, with everything else muted. If it's fine on its own, skip to the last section — you have a mix problem, not a volume problem.
Cause 1 — The app's own volume is turned down
Most media apps carry an internal level that's completely independent of your Mac's master volume. Spotify, VLC, web players, Discord, conferencing tools, and games all have their own slider, and it doesn't move when you press the volume keys. If that internal slider is at 40%, the app tops out at 40% no matter how loud the system is. This is the single most common reason one app stays quiet.
Open the app and find its own volume control first. In browsers, check the tab's player and the site's volume. In games, check the in-game audio menu. In Discord, check both the app volume and the per-user output sliders. It sounds obvious, but a stray internal slider is behind these complaints more often than any system setting.
Cause 2 — Output Balance has drifted off-center
macOS has a left/right Balance slider under System Settings → Sound → Output. When it's centered, both channels are equal. When it slips toward one side — and it does slip, sometimes on its own after sleep or a device change, a long-standing macOS quirk — audio collapses toward one ear or one speaker and the whole thing feels quiet. If everything sounds low, or louder on one side, this is the first system setting to rule out. Drag the Balance slider back to dead center.
Cause 3 — Headphone Safety is capping the volume
If the app is only quiet in headphones, macOS is probably protecting your ears. Headphone Safety (also called Reduce Loud Audio) limits headphone output based on how loud and how long you've been listening. It only affects headphones — not speakers — which is exactly why an app can sound fine on the laptop speaker and then feel weak the moment you plug in. Check System Settings → Sound, or Accessibility → Audio, and adjust or disable the loud-sound reduction if you don't need it.
Cause 4 — The audio is going to a quieter device
An app can end up on a different output than you assume — a Bluetooth speaker still connected across the room, an HDMI monitor with its own volume, or a headset whose hardware dial is turned down. macOS sets one system output, but some apps remember their own device, and device volumes are separate from the master. If one app is quiet and the rest are fine, confirm what device it's actually playing through. If you routinely send different apps to different outputs, our guide on how to send an app's audio to a different output on Mac walks through doing it deliberately instead of by accident.
Cause 5 — The source itself is just quiet
Sometimes nothing is wrong with your Mac. A poorly mastered video, a low-gain podcast, or a quiet recording simply has less level than a loud, normalized music track. macOS has no per-app amplifier to push a single app past 100%, so there's no system slider that will "boost" it above its own ceiling. When the source is the problem, your best levers are the app's own boost (some players, like VLC, can exceed 100% internally) and rebalancing everything else downward — which brings us to the fix that actually works day to day.
The fix that works: keep it at 100%, turn everything else down
Here's the mindset shift. When one app is too quiet, the instinct is to make it louder. But if it's already maxed, the only headroom left is in the other direction: leave the quiet app at 100% and pull every competing app down so the quiet one dominates the mix. You get the same relative result — the app you care about is now the loudest thing you hear — without cranking the master volume and blasting your ears when a notification hits.
The problem is that doing this by hand is tedious. Every app hides its slider in a different place, and you're hunting through windows every time the mix shifts. That's the exact friction a per-app volume mixer removes — it puts every running app's level in one place. For the background on why macOS makes you reach for one at all, see how to control individual app volume on a Mac.
| Symptom | Most likely cause | Fastest fix |
|---|---|---|
| Quiet on its own, everywhere | App's internal slider is down | Raise the app's own volume control |
| Quiet and lopsided left/right | Output Balance off-center | Recenter Balance in Sound settings |
| Quiet only in headphones | Headphone Safety limit | Adjust Reduce Loud Audio |
| Quiet on one output only | Wrong / quiet device | Check the app's output device + its hardware dial |
| Fine alone, buried in the mix | Other apps are just louder | Lower the loud apps; keep this one at 100% |
Why a keyboard makes the rebalance actually happen
Rebalancing only helps if it's fast enough to do the moment the mix goes wrong. A menu-bar list means: reach the menu bar, click the icon, find each app's row, drag it, dismiss. Do that every time a call gets buried under music and you'll stop bothering. Fader's approach is to make the keyboard the mixer — you hit a toggle hotkey and letter keys become per-app faders, so dropping the three loud apps and leaving the quiet one alone takes a second without your hands leaving the keys. That's the difference between a fix you know about and a fix you'll use twenty times a day.
Where the paid mixers stand
A few apps live in this space, and they're honestly different tools. Background Music is free and open source, and mixes per-app volume from a menu-bar list. SoundSource, from Rogue Amoeba, is deep and polished — per-app volume, routing, and EQ — at $49 one-time. Fader is $19.99 one-time and built around keyboard speed: the fastest way to ride and rebalance levels, plus per-app output devices, with a 3-day free trial and no account. None of them can amplify a single app past its ceiling — that's a macOS limitation, not a feature any of them hide — but all of them make the "turn everything else down" fix quick instead of painful.
Bottom line
When one app is too quiet at full volume on a Mac, check the boring stuff first: the app's own slider, the Balance slider, Headphone Safety, and the output device — in that order. Those solve most cases outright. When the app is genuinely fine and just loses to a louder mix, stop trying to make it louder and make everything else quieter instead. A keyboard-driven per-app mixer turns that rebalance into a one-second habit, which is exactly what Fader is built for.
Rebalance every app from your keyboard
Fader turns letter keys into per-app faders — drop the loud apps, keep the quiet one at 100%, in a keystroke. $19.99 one-time, 3-day free trial, no account. macOS 14.4+.