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.

I tested this on my Noble Mystique and Sony 1000xm4 and I'm not sure why the Sony gets shafted here. I know the Mystique uses AptX and 1000xm4 uses LDAC, but it doesn't matter here anyways.

Noble Mystique:

A2DP configured at 44.1 KHz. Codec: AAC-LC, VBR max: 256 kbps. 1 frames * (12+744) bytes = 756 per RTP (max=879) every 23.22 ms

ACMP4AACBaseEncoder.cpp:650   (0x125244440) @@@@ 'aac ' encoder configuration: srIn = 44100, srOut = 44100, chans = 2, bitRateFormat = 1, bitrate = 128000, quality (complexity) = 64, VBRQ = -1, speechOptimization = 0, packetSizeLimit = 0 (bits), packetBitSizeMin = 0 (bits), mMaxPacketSize = 1536 (bytes), userBandwidth = 0, delayMode = 0, mCodecDelay = 2112, drcConfiguration = 0, mPrePostFillMask = 0x0

ACMP4AACBaseEncoder.cpp:650   (0x125244440) @@@@ 'aac ' encoder configuration: srIn = 44100, srOut = 44100, chans = 2, bitRateFormat = 3, bitrate = 192000, quality (complexity) = 32, VBRQ = -1, speechOptimization = 0, packetSizeLimit = 5952 (bits), packetBitSizeMin = 256 (bits), mMaxPacketSize = 1536 (bytes), userBandwidth = 0, delayMode = 0, mCodecDelay = 2112, drcConfiguration = 0, mPrePostFillMask = 0x0

Sony 1000xm4:

A2DP configured at 44.1 KHz. Codec: AAC-LC, VBR max: 192 kbps. 1 frames * (12+558) bytes = 570 per RTP (max=656) every 23.22 ms

ACMP4AACBaseEncoder.cpp:650   (0x124b34e40) @@@@ 'aac ' encoder configuration: srIn = 44100, srOut = 44100, chans = 2, bitRateFormat = 1, bitrate = 128000, quality (complexity) = 64, VBRQ = -1, speechOptimization = 0, packetSizeLimit = 0 (bits), packetBitSizeMin = 0 (bits), mMaxPacketSize = 1536 (bytes), userBandwidth = 0, delayMode = 0, mCodecDelay = 2112, drcConfiguration = 0, mPrePostFillMask = 0x0

ACMP4AACBaseEncoder.cpp:650   (0x124b34e40) @@@@ 'aac ' encoder configuration: srIn = 44100, srOut = 44100, chans = 2, bitRateFormat = 3, bitrate = 144000, quality (complexity) = 32, VBRQ = -1, speechOptimization = 0, packetSizeLimit = 4464 (bits), packetBitSizeMin = 256 (bits), mMaxPacketSize = 1536 (bytes), userBandwidth = 0, delayMode = 0, mCodecDelay = 2112, drcConfiguration = 0, mPrePostFillMask = 0x0

I'm on sonoma and my xm4 get 256 for max VBR

I tested this on my Edifier W820NB and output this log
A2DP configured at 44.1 KHz. Codec: SBC, Bitpool: 52 (322 kbps). 5 frames * 117 bytes = 585 per RTP (max=663) every 14.51 ms
ACSBCEncoder.cpp:214 (0x7fd93aa74cc0) Output format: 2 ch, 44100 Hz, sbc (0x00000000) 0 bits/channel, 0 bytes/packet, 0 frames/packet, 0 bytes/frame

@Eugene-Y
I can't speak for all MacOS versions, but I do this on Monterey:

1. Disconnect your headphones.
2. Open the "Console" app (Under "Applications/Utilities").
3. In the "Search" field, in the upper-right corner, type "Codec", and hit "Enter".

These instructions don't work on Ventura. Console doesn't show anything even before filtering.
It would be better to know the log file I'm supposed to be monitoring so I can use the terminal instead of Apple's silly app

@ballo
These instructions don't work on Ventura. Console doesn't show anything even before filtering.
It would be better to know the log file I'm supposed to be monitoring so I can use the terminal instead of Apple's silly app

You need to hit "Start" as well before reconnecting your headphones. It works on Sonoma.

On Sonoma for modern BT5 headphones (like OneOdio Pro C):

defaults write com.apple.BluetoothAudioAgent "Apple Bitpool Max (editable)" 80;
defaults write com.apple.BluetoothAudioAgent "Apple Bitpool Min (editable)" 80;
defaults write com.apple.BluetoothAudioAgent "Apple Initial Bitpool (editable)" 80;
defaults write com.apple.BluetoothAudioAgent "Negotiated Bitpool" 80;
defaults write com.apple.BluetoothAudioAgent "Negotiated Bitpool Max" 80;
defaults write com.apple.BluetoothAudioAgent "Negotiated Bitpool Min" 80;
defaults write com.apple.BluetoothAudioAgent "Stream - Flush Ring on Packet Drop (editable)" 0;
defaults write com.apple.BluetoothAudioAgent "Stream - Max Outstanding Packets (editable)" 16;
defaults write com.apple.BluetoothAudioAgent "Stream Resume Delay" "0.75"

defaults write bluetoothaudiod "Enable AAC codec" -bool true
defaults write bluetoothaudiod "AAC Bitrate" -int 320
defaults write bluetoothaudiod "AAC max packet size" -int 644

Don't forget to reset the bluetoothd daemon:

sudo pkill bluetoothd

I hope it helps.

How enable ldac on macOS?

For everyone struggling with Sony headphones, "Sound Quality Mode" can be changed manually without the app. The instruction below is for the MDR-650BT, but also worked for my old MDR-950B1.
https://helpguide.sony.net/mdr/xb650bt/v1/en/contents/TP0001034995.html
Previously connecting to SBC, now successful: A2DP configured at 44.1 KHz. Codec: AAC-LC [...].

On Sonoma for modern BT5 headphones (like OneOdio Pro C):

defaults write com.apple.BluetoothAudioAgent "Apple Bitpool Max (editable)" 80;
defaults write com.apple.BluetoothAudioAgent "Apple Bitpool Min (editable)" 80;
defaults write com.apple.BluetoothAudioAgent "Apple Initial Bitpool (editable)" 80;
defaults write com.apple.BluetoothAudioAgent "Negotiated Bitpool" 80;
defaults write com.apple.BluetoothAudioAgent "Negotiated Bitpool Max" 80;
defaults write com.apple.BluetoothAudioAgent "Negotiated Bitpool Min" 80;
defaults write com.apple.BluetoothAudioAgent "Stream - Flush Ring on Packet Drop (editable)" 0;
defaults write com.apple.BluetoothAudioAgent "Stream - Max Outstanding Packets (editable)" 16;
defaults write com.apple.BluetoothAudioAgent "Stream Resume Delay" "0.75"

defaults write bluetoothaudiod "Enable AAC codec" -bool true
defaults write bluetoothaudiod "AAC Bitrate" -int 320
defaults write bluetoothaudiod "AAC max packet size" -int 644

Don't forget to reset the bluetoothd daemon:

sudo pkill bluetoothd

I hope it helps.

But the bitrate value in console hasn't changed🤔

But the bitrate value in console hasn't changed🤔

Try by restarting the computer. If that doesn't work it probably means your headphones are not capable of higher bitrates.

Also you could try the increasing the bitpool even more. It probably won't work if the headphones have a limit, but it's worth trying:

defaults write com.apple.BluetoothAudioAgent "Apple Bitpool Max (editable)" 320;
defaults write com.apple.BluetoothAudioAgent "Apple Bitpool Min (editable)" 2;
defaults write com.apple.BluetoothAudioAgent "Apple Initial Bitpool (editable)" 320;
defaults write com.apple.BluetoothAudioAgent "Negotiated Bitpool" 320;
defaults write com.apple.BluetoothAudioAgent "Negotiated Bitpool Max" 320;
defaults write com.apple.BluetoothAudioAgent "Negotiated Bitpool Min" 2;
defaults write com.apple.BluetoothAudioAgent "Stream - Flush Ring on Packet Drop (editable)" 0;
defaults write com.apple.BluetoothAudioAgent "Stream - Max Outstanding Packets (editable)" 1;
defaults write com.apple.BluetoothAudioAgent "Stream Resume Delay" "0.75"

defaults write bluetoothaudiod "Enable AAC codec" -bool true
defaults write bluetoothaudiod "AAC Bitrate" -int 320
defaults write bluetoothaudiod "AAC max packet size" -int 644

But the bitrate value in console hasn't changed🤔

Try by restarting the computer. If that doesn't work it probably means your headphones are not capable of higher bitrates.

Also you could try the increasing the bitpool even more. It probably won't work if the headphones have a limit, but it's worth trying:

defaults write com.apple.BluetoothAudioAgent "Apple Bitpool Max (editable)" 320;
defaults write com.apple.BluetoothAudioAgent "Apple Bitpool Min (editable)" 2;
defaults write com.apple.BluetoothAudioAgent "Apple Initial Bitpool (editable)" 320;
defaults write com.apple.BluetoothAudioAgent "Negotiated Bitpool" 320;
defaults write com.apple.BluetoothAudioAgent "Negotiated Bitpool Max" 320;
defaults write com.apple.BluetoothAudioAgent "Negotiated Bitpool Min" 2;
defaults write com.apple.BluetoothAudioAgent "Stream - Flush Ring on Packet Drop (editable)" 0;
defaults write com.apple.BluetoothAudioAgent "Stream - Max Outstanding Packets (editable)" 1;
defaults write com.apple.BluetoothAudioAgent "Stream Resume Delay" "0.75"

defaults write bluetoothaudiod "Enable AAC codec" -bool true
defaults write bluetoothaudiod "AAC Bitrate" -int 320
defaults write bluetoothaudiod "AAC max packet size" -int 644

I'm using an "Alternative A2DP Driver" on Windows PC and it works properly with higher bitpool values. Anyway, now I'm trying to enable 320kbit/s bitrate for AAC codec.

BT Receptor UGREEN-40759P

A2DP configured at 44.1 KHz. Codec: AAC-LC, VBR max: 256 kbps. 1 frames * (12+744) bytes = 756 per RTP (max=879) every 23.22 ms

Enabled:
sudo defaults write bluetoothaudiod "Enable AptX codec" -bool true
sudo defaults write bluetoothaudiod "Enable AAC codec" -bool true

Verify with:
sudo defaults read bluetoothaudiod