How headphone control
works on a Mac

Two connections, two jobs

When your headphones connect to a Mac, macOS sets up the audio connection: stereo playback, and a headset mode for calls when an app uses the microphone. That's all macOS needs, so it has no screen for noise canceling or an equalizer.

The headphones also publish a control service: a small Bluetooth channel for messages like "switch to ambient sound" or "set this equalizer curve", with replies such as "battery at 80 %". Sony's phone app uses it. Open Sound Connect opens the same kind of channel from your Mac.

The two are independent:

• Audio can play while the controls aren't connected (that's why music works when the app is closed).
• Disconnect Controls (⇧⌘K) closes only the control channel; your audio stays connected.
• If the control channel can't open (Bluetooth access off, headphones busy or out of range) the app says so, and audio is unaffected. See headphones connected but not detected.

Reading what each model has

The headphones describe themselves when the control channel opens: their model name, firmware version, battery and the list of settings they support. Open Sound Connect shows a control only when the headphones list it, so a WH-1000XM6 shows listening modes and an MDR-1000X shows no equalizer. Two generations of Sony's protocol exist; the app picks the right one from the service the headphones advertise, not from their name.

That's also why the same model can show slightly different options with different firmware: the app follows what the headphones report. The Activity page (⌘7) lists exactly what yours reported.

Every change is read back

When you change a setting, the app sends it and waits for the headphones to confirm it. The control updates to what the headphones actually kept, and Activity records each change as applied or not. Some changes, such as turning on two-device connections or choosing sound quality over connection stability, make the headphones reconnect; the app waits for them and reconnects by itself.

Where your settings live

This is why Sony EQ settings carry over between your Mac and phone, while scenes don't.

What the app doesn't do

• It doesn't process audio on your Mac or change what macOS sends; the equalizer runs in the headphones.
• It doesn't add codecs: on a Mac, Bluetooth audio uses what macOS supports. See LDAC, AAC and lossless on a Mac.
• It doesn't update headphone firmware; that's done with Sony's phone app. See firmware updates.

Privacy

The control messages travel only between your Mac and your headphones. The app has no analytics and sends nothing about your headphones or listening anywhere. Website downloads check a license and look for updates; the Mac App Store version makes no network connections at all. The privacy policy has every detail.