How to fix the crackling bad sound of Bluetooth A2DP headsets or speakers on Mac OS X

If you found this post you probably ran into the same issue as I had, low volume on your headset or speakers or crackling sound.

The solution for this might sound more complex than it is, the Bitpool for the Bluetooth Audio Agent by default is 35, this seems to be too low if you also use a mouse and keyboard at the same time. In my case only a mouse. Raising it to a higher value solved this problem for me.

I raised it to 50 and it worked perfectly!

You can edit the preference file with a plist editor in this file: ~/Library/Preferences/

Or, more simple, you can run the following in the program Terminal located at /Applications/Utilities/

At the command line enter the following command:

After doing this you might need to reconnect your device or reboot your Mac to apply the change. In my case turning off the bluetooth adapter and enabling it again was enough.

I tested this with a Sennheiser PX 210 BT and it works perfectly!

In case you want to revert to the default settintgs, simply trash:


Updated @ 03-01-2013

It seems that a Macbook Air has a default value of 2. So far, I haven’t noticed bad sound with this system.
Here the default settings:

Updated @ 06-02-2013

After some testing for my Sennheiser PX210 BT it seems that the settings below seem to do the perfect job.

You might want to play around with the Bitpool settings in case these don’t work perfectly for you.

I noticed some difference when locking the Bitpool to a more strict range, these are the values that I tested:

  • 30 – Low audio quality
  • 40 – Medium audio quality
  • 48 – High audio quality
  • 58 – Excellent audio quality

I found these numbers on the Apple discussion forum, seems that still a lot of people seem to have problems with their audio quality.