How to play music on a Bluetooth speaker while calls go to your headset on a Mac

The direct answer: macOS sends every app to one output device at a time, so the built-in Sound settings can't play music on your Bluetooth speaker while calls stay private in your headset — pick one device and everything follows it. What you want is per-app output routing: pin your music app to the speaker and your call app to the headset as two separate rules. You can do it for free if each app has its own output picker, or set it once in a routing app and forget it. macOS can drive both outputs at the same time; the only real catch is running two Bluetooth streams at once.

The scenario is a good one: music filling the room from a Bluetooth speaker while your calls stay in a headset that only you can hear — no bleed, no one on the call catching your playlist, no killing the music every time someone dials in. It's exactly the kind of split macOS makes needlessly hard, because it treats all of your audio as one stream headed for one device.

Why the Sound menu can't split two apps to two devices

On a Mac there is exactly one active output device at a time. Open System Settings → Sound and the Output tab is a single list where you pick one device — internal speakers, the Bluetooth speaker, the headset — and every app is routed to whatever you chose. There is no per-app column, no way to say "music here, calls there." Choose the speaker and your call plays out loud for the room; choose the headset and your music is trapped in your ears. That's the whole limitation, and it's the output-side twin of the per-app volume problem on macOS: the system was built around one global setting, not a mixer.

So the goal is to make two apps ignore the system default and go to devices you name. macOS doesn't expose that directly. Here are the honest ways to get it, cheapest first.

The free path: each app's own output picker

Start with what might already be sitting in your preferences. A handful of apps carry their own audio-output setting — VLC, some DAWs and media tools, a few games with an audio-device option, and certain calling apps. If your music player and your call app each have one, you're done for free: point the music app at the Bluetooth speaker, point the call app at the headset, and set the system output to whichever you use most. Nothing to install, and it's a complete fix when both apps cooperate.

The trouble is that most apps don't. Spotify, Apple Music, Chrome, Slack, and most video-call apps have no output picker at all — they simply hand their audio to whatever the system output is. The moment one of your two apps lacks its own device setting, the free "use the app's picker" route can't finish the split, and you're back to the OS limitation.

The free-but-fiddly path: BlackHole and Audio MIDI Setup

For apps with no picker, the free route is BlackHole — a free, open-source virtual audio device — combined with macOS's built-in Audio MIDI Setup. You install BlackHole (a one-line Homebrew command or a signed installer), then use Audio MIDI Setup to build aggregate or multi-output devices and route audio through them. Audio tinkerers rely on it, and it's a genuinely capable free tool.

The honest catch is that BlackHole is designed to pass audio between apps and to duplicate one stream across several outputs — not to hand you a clean "music app to this device, call app to that device" switch. Getting exactly two apps onto two different physical outputs usually still leans on each app's own picker or a hand-built chain of aggregate devices you maintain yourself. It works, but it's more setup and more upkeep than most people want for an everyday music-and-calls split.

The gotcha worth knowing: Background Music is volume, not output

Background Music comes up constantly as the free per-app answer, and it's genuinely good — but it does volume, not per-app output. As of 2026 it keeps every app on the same system output device; per-app output-device selection is a long-standing open feature request on the project, not a shipping capability. So for "send music to the speaker but calls to the headset," Background Music can balance the levels but can't perform the actual routing. Worth knowing before you install it expecting it to split your outputs.

The set-it-once path: a per-app routing app

A routing app does at the OS level what these apps won't do themselves: it assigns each app its own output device, independent of the system default. You set the default output to, say, your headset, then add two rules — music app → Bluetooth speaker and, if needed, call app → headset — and each app goes where you told it. Because the routes are held per app, they reapply when the apps relaunch or the devices reconnect, so you're not re-picking in the Sound menu every session.

SoundSource from Rogue Amoeba is the deep option: it sends individual apps to different outputs, layers on EQ and effects, and version 6 (December 2025) added Output Groups for routing to several devices at once plus expanded AirPlay support. It's a one-time $49. Fader does the same per-app output routing in a plain list — choose a device per app and it sticks — for a one-time $19.99, and the same app rides per-app volume from your keyboard, so you can nudge the music down without leaving your call. Here's how the options stack up for this exact speaker-versus-headset split.

The exact setup: music to the speaker, calls to the headset

With a per-app routing app installed, the recipe is short:

1. Pair both devices — your Bluetooth speaker and your headset — so macOS sees them in the output list. 2. Set the default system output to one of them; the headset is a good default so a surprise notification doesn't blast the room. 3. Add a route for your music app and choose the Bluetooth speaker as its output. 4. Add a route for your call app pointed at the headset (or, if the headset is your default, the call already lands there and you're done). 5. Leave it. Every other app inherits the default; the two you routed go where you sent them and return there on reconnect.

In Fader that's the Routing tab: the default output sits at the top and each app route is a row — App → Device — from a dropdown. Because the same app also gives every running app a fader on your keyboard, you can duck the music with letter keys the instant a call starts, then bring it back when you hang up, without touching the mouse. If you want the broader picture of steering apps to different outputs, the companion guides on routing an app's audio output on a Mac and sending one app to headphones while everything else plays on speakers cover the same idea for other device pairs.

The Bluetooth catch, honestly

Two things about Bluetooth are worth saying plainly. First, running two Bluetooth outputs at once — speaker and headset — means both streams share the same radio, and on some Macs that can show up as occasional stutter or a dropout under load. If you hit it, the clean fix is to keep the music on the Bluetooth speaker and move the call to a wired or USB headset; that takes one stream off Bluetooth entirely and the contention disappears. Second, Bluetooth adds a little latency, which is invisible for music and voice calls but not ideal for tight lip-sync or gaming — again, a wired output is the better ear there. None of this is a Fader-versus-anything difference; it's just how Bluetooth on macOS behaves, and it's the same for every routing method above.

Bottom line

macOS points every app at a single output, so keeping music on a Bluetooth speaker while calls stay in your headset isn't something the Sound menu can do — pick one device and both apps follow it. If each app has its own output picker, use them and it's free and done. If you like tinkering, BlackHole plus Audio MIDI Setup is capable but fiddly for this, and Background Music won't do output routing at all. If you'd rather set two rules and move on — music to the speaker, calls to the headset — a per-app routing app is the straight path. SoundSource is the deep, $49 option; Fader does the routing plus keyboard-fast per-app volume for $19.99 one-time. And if two Bluetooth streams ever stutter, put the call on a wired headset and keep the speaker on Bluetooth.