Enable High Quality mode on your headphones (Updated for macOS Catalina)

change-codec.md

If you're using a high-end bluetooth headset on your Macbook Pro it's likely your mac is using an audio codec which favors battery efficiency over high quality. This results in a drastic degradation of sound, the SBC codec is the likely culprit, read more about it here.

Find out what codec you're using

1. Play a song on your headphones
2. Option (⌥) click the Bluetooth button at the top of your screen
3. If you're using AAC or aptX, you can stop here—those are the highest quality codecs.

Change your codec to AAC or aptX

UPDATE: It looks like Apple has silently dropped support for aptX, leaving only AAC

You'll need to download Apple's Bluetooth Explorer in order to change codecs.

1. Head over to Apple's Developer Downloads

2. Search for additional tools and download Additional Tools for XCode 11.dmg

3. Open the dmg, and open Bluetooth Explorer

4. Click on Tools > Audio Options and change your audio codec to the following settings:

   • Enable AAC
   • Force use of aptX
   

5. Disconnect your Bluetooth headset, reconnect it, and while some music is playing, inspect your codec. It should now show either AAC or aptX.

   

Squeezing the most out of AAC

You can increase the AAC bitrate in Audio Options but be sure to keep an eye on the graphs. The retransmission percentage is roughly equivalent to packet loss, and if you increase the bitrate too high your audio will start cutting out:

The retransmission rate is a function of distance and interference, and you'll need to disconnect/reconnect on each attempt before you find the sweet spot.

This is really disappointing. Thanks for the research @nicolaskopp

After extensive research, I found that Apple has systematically removed native support for the aptX Bluetooth codec from its operating systems, beginning with macOS Catalina (10.15) and continuing through all subsequent versions, including Monterey, Ventura, and Sonoma [1][2].

This means that regardless of the terminal commands used or developer tools accessed, a Mac running Sonoma cannot natively transmit audio using any variant of the aptX codec. The operating system's Bluetooth stack no longer includes the necessary software to encode and send an aptX audio stream. This Gist and many older guides found online refer to methods that are now deprecated and will not work on modern systems [3].

Another user on the Apple Support Community, after extensive troubleshooting on a MacBook Air M2 with Sonoma, concluded:

"In the end, a lot of time was spent trying to find a solution to my question, but all in vain, and as I understand it, it is all due to software limitations on the Sonoma side." [4]

This sentiment is echoed across numerous sources, confirming that the issue is not a bug but a deliberate decision by Apple.

With aptX removed, macOS Sonoma natively supports the following primary Bluetooth audio codecs:
Codec Quality Bitrate Notes
AAC High ~256 kbps (VBR) Best native option. Apple has a high-quality implementation. Requires headphone support.
SBC Standard ~328 kbps The universal, mandatory Bluetooth codec. Quality is generally considered inferior to AAC and aptX.

For most users, AAC (Advanced Audio Coding) is the highest-quality codec available natively on macOS. If your headphones support AAC, your Mac should automatically select it to provide a good listening experience. You can verify the active codec using the Console application as described in the comments on this Gist.

Since native software solutions are impossible, it seems that the only effective method to use aptX on a Mac running Sonoma is to bypass the internal Bluetooth hardware and software entirely. This might be achieved by using an external USB Bluetooth audio transmitter.

Hello, have you done any research on increasing the AAC bitrate? My device has been stuck at 128 kbps, and I haven't found any viable solutions yet.

Hello, have you done any research on increasing the AAC bitrate?

No.