Headphones and a Mac: the Bluetooth quality question
· 5 min read
Music through Bluetooth headphones sounds good. Join a call and it sounds noticeably worse, both for you and for the person listening. Nothing has broken; Bluetooth has switched modes.
Two modes, one connection
Bluetooth audio operates in two distinct profiles.
A2DP is the one-way, high-quality mode. Audio flows to the headphones and the microphone is unused. This is what plays music.
HFP or HSP is the two-way mode, used when the microphone is needed. Bandwidth is shared between outgoing and incoming audio, so the quality of both drops.
The switch happens automatically when an application requests the microphone. It is not something you configure, and it is why audio degrades exactly when you join a call.
What you can actually do about it
Use the headphones for listening and something else for the microphone. The Mac’s built-in array is genuinely good and is often better than the headset microphone anyway. In System Settings, Sound, set Output to the headphones and Input to the MacBook microphone.
This is the single best fix, it costs nothing, and it keeps the headphones in high-quality mode because their microphone is never requested.
The caveat: your own voice will be picked up by the Mac, so you need to be reasonably close to it, and echo can occur if the volume is high. Usually fine at normal levels.
Use wired headphones for calls. No mode switching, no latency, no battery. Unfashionable and reliable.
Accept it. For internal meetings, the quality is perfectly adequate and the convenience is real.
Latency
The other Bluetooth trade. There is a delay between the Mac sending audio and you hearing it, typically well under a second and enough to matter in two situations.
Playing an instrument or recording, where any delay is disruptive. Use wired.
Video where lip sync matters. Most players and video applications compensate automatically, and occasionally they get it wrong. Reconnecting usually resolves it.
For ordinary listening and calls it is not noticeable.
Codecs, briefly
macOS supports AAC and SBC for Bluetooth audio. It does not support aptX or LDAC, so headphones advertising those fall back to AAC on a Mac.
AAC is good. The practical consequence is that a headphone’s high-end codec support is not a selling point for Mac use, and you should not pay extra for it.
AirPods specifically
They work well and have two Mac-specific advantages: automatic switching between devices on the same Apple Account, and Find My integration.
Automatic switching is also the most common complaint, because they hop to the iPhone mid-task. It can be turned off: in Bluetooth settings, click the info button beside the AirPods, then set Connect to This Mac to “When Last Connected to This Mac” rather than automatically.
When audio goes wrong
Three common problems and their causes.
Choppy or stuttering audio. Interference, usually from a crowded 2.4 GHz band. Move closer, and consider that a busy Wi-Fi environment shares that spectrum.
Headphones connect but no sound. The output device is set elsewhere. System Settings, Sound, Output.
They connect to the phone instead. Automatic switching. Change the setting above.
No sound from a Mac, or sound from the wrong device covers the wider diagnosis.
Using them for both, properly
If you must use the headset microphone, one improvement is available: turn on Voice Isolation during the call, from Control Centre, Mic Mode. It cannot recover the lost bandwidth and it does clean up what is there.
Microphones for calls covers the alternatives in more detail.
Questions
Why do my headphones sound worse on a call than on my phone? They probably do not; the same mode switch happens on a phone. It is more noticeable on a Mac because you were likely listening to something high quality immediately beforehand.
Does the Mac’s headphone jack sound better? Yes, meaningfully, and with no latency. On Macs that have one, it remains the better option for critical listening.
Can I use two Bluetooth headphones at once? Not simply. Audio MIDI Setup can create an aggregate output device, which works with variable reliability for Bluetooth.
Is Bluetooth audio quality improving? Slowly. The two-mode limitation is fundamental to how the profiles work, and newer standards address it, and support has to exist on both ends.