How to tame one loud Electron app (Slack, Discord) on a Mac

Slack and Discord feel louder than everything else because they're Electron apps: they play their notification and system sounds through your Mac's single output at whatever level they choose, and neither one gives you a real volume slider for those sounds. macOS has no per-app volume to fall back on, so the ding lands at full output while your music sits underneath. To cap one loud app without silencing it — or muting the rest of your Mac — you install a per-app mixer, give that app its own channel, and set a ceiling.

It's a specific kind of annoying. You've got music going, a video playing, maybe a call queued up — and then a Slack message or a Discord join sound cuts through it all like it owns the room. You didn't ask for it to be the loudest thing on your machine. But short of turning the whole app's sounds off, there's no obvious way to just turn it down. This guide explains why that happens and what actually fixes it.

Why Electron apps end up the loudest thing on your Mac

Slack, Discord, and a long list of other desktop apps are built with Electron — essentially a Chromium browser wrapped around a web app. That's a fine way to ship software, but it means the app plays audio the way a web page does: straight to the system's one output device, at whatever level its own code specifies. There's no dial in the app that says "all my sounds, quieter."

Normally you'd reach for a per-app volume control to fix that. On Windows, you'd open the Volume Mixer and drag Slack's bar down. On a Mac, there's nothing to open. macOS routes every app through a single master output, and the volume keys move all of it together. So a loud Electron app has two things working against you at once: the app won't turn itself down, and the OS won't turn it down for you.

What Slack and Discord actually let you control

The frustrating part is that both apps look like they have sound settings. They just aren't volume settings.

In Slack, you can choose which notification sound plays, or switch sounds off entirely — but there's no slider between "full volume" and "silent." It's a binary. If Slack's chime is too loud, your only in-app option is to mute it and risk missing messages. If quieting Slack specifically is your goal, we go deeper in how to quiet Slack notifications without muting your music on Mac.

Discord has more knobs, but the same gap. Its Voice & Video settings include an output volume slider, and that governs the audio you hear from people in a voice channel. The sounds that usually feel "too loud," though — the notification pings, the join and leave blips, the incoming call ring — live under Notifications and User Settings as on/off toggles, not levels. You can silence a category, but you can't set it to 30 percent. When the loud part is a game rather than the chat, see how to lower Discord's volume without turning down your game on Mac.

So in both apps, the honest summary is: you get on/off, not up/down. That's exactly the control gap a per-app mixer fills.

The fix: give the loud app its own fader

A per-app volume mixer sits at the macOS audio layer — below the apps, above the output device — and gives every running app its own level in one place. That's the piece Apple never shipped. Put a ceiling on Slack or Discord there, and its sounds land at whatever level you set while everything else keeps playing at full. Nothing gets muted; the loud app just stops being loud.

A few tools do this, and they're honest, established options. Here's how they compare for the specific job of capping one noisy app.

Background Music is a genuinely good free option — it's open source, it works, and if you want per-app levels at no cost it's the first thing to try. SoundSource, from Rogue Amoeba, is the deep, polished pick: per-app volume, routing, and EQ, at roughly $49 one-time. Fader is the keyboard-first one, priced at $19.99 one-time. None of these is a subscription. Which fits depends on how you want to reach the control.

Why reaching it fast matters for a loud app specifically

Here's the thing about a loud Electron app: the moment you most want to turn it down is the moment it's already blasting. A menu-bar list means you notice the noise, move to the menu bar, click the icon, find the app's row, drag the bar, and dismiss the panel — by which point the sound is over and you've lost your place in whatever you were doing. It works, but it always lags the problem.

Fader's approach is to keep the control under your fingers. You hit a toggle hotkey and the keyboard becomes a mixer — one letter column per app — so you can ride Slack or Discord down without reaching for the mouse. Or you bind a dedicated hotkey to the loud app and drop it, or mute it outright, in a single keystroke the instant it acts up. For a sound that's annoying precisely because it's sudden, being one key away is the whole point.

A quick setup that sticks

Whatever mixer you pick, the setup is the same shape. Install it, let it see your audio, find the loud app in the app list, and pull its level down to something that coexists with your music instead of stomping on it — 30 to 50 percent is a good starting point for notification-heavy apps. Then leave it. The ceiling holds across restarts, so you set it once and the app simply stops being the loudest thing you own.

In Fader you'd go one step further and assign that app a hotkey, so on the rare loud day you can cut it to zero without breaking focus. The mix you set is the baseline; the keyboard is there for the exceptions.

Bottom line

A loud Electron app like Slack or Discord isn't misbehaving — it's doing what Electron apps do, playing to your Mac's one output with no volume of its own, on an OS that has no per-app mixer to rein it in. The apps only offer on/off, so the real fix is a per-app volume tool: cap the noisy app, leave everything else alone. Background Music does it free; SoundSource does it deeply; Fader does it from the keyboard, so the control is already in your hands the second the app gets loud.