When we connect wireless or Bluetooth headphones to our Mac, the audio may not be as satisfying as when we listen to music on a smartphone or on another computer. This discrepancy in quality is caused by the use of a low quality audio codec by the Bluetooth module integrated in the Mac. If we have encountered this problem, you have come to the right guide: here in fact we will show you how to improve the sound of the headphones on Mac acting on the audio codec used to transmit the audio, so as to use only the one that allows to obtain the highest quality with any streaming app and with iTunes. In the guide we will show you first of all which codecs can be used by Bluetooth to transmit audio, how to check what type of codec is currently using the Mac and how to change it on the fly, so as to obtain the desired audio quality.
READ ALSO: How to improve the sound of wireless headphones (PC and smartphone)
Types of Bluetooth audio codecs
When we connect a Bluetooth headset or headset to the Mac, one of the following codecs is used to transmit the audio:- SBC
- AAC
- aptX
The basic codec is SBC, used on the vast majority of headphones and earphones but which does not allow to obtain the maximum audio quality, also presenting problems of latency and low volume with many streaming devices and services. The AAC codec has significant improvements in audio compression, bringing audio to a much higher level, especially with higher bitrates (which is very common when this codec is used). The highest audio quality can only be obtained with aptX : constant bitrate, no cut of frequencies and sound performance completely similar to that of Audio CDs. Unfortunately, in order to take advantage of the two best codecs (AAC and aptX), support from the headphones is also required, otherwise the Bluetooth module will always transmit with the SBC codec.
If we have a pair of modern Bluetooth headphones with AAC or aptX support but the audio seems to us of low quality, probably the Mac is transmitting in SBC (for some error in the recognition), not allowing us to make the most of the quality of our headphones. In the following chapters we will show you how to control the codec in use on Bluetooth headphones and how to force the Bluetooth module of the Mac to use AAC or aptX (if supported).
Check the audio codec in use
Once the Bluetooth headphones are connected to the Mac, we click on the Bluetooth icon at the top right, then select the name of the headphones from the list shown in the window. Among the obscured voices (not clickable) we will also find Active Codec, which will show us which codec we are currently using to transmit audio to headphones.
If we find the AAC or aptX codecs under this heading, we will not have to do anything else, since we are already using the best codecs available to obtain the best audio quality with our wireless headphones; if instead we see the SBC codec appear and we are sure that our headphones support AAC or aptX, we see in the following chapter how to force the higher quality codec.
How to improve headphone audio on Mac
In order to improve the audio transmitted to the headphones connected to the Mac, we will have to download the Additional Tools for Xcode from the Apple developer website. In order to download it we need a free Apple developer account, which we can get from the Apple Developers page. Once registered as a developer, we download the recommended file at the beginning of the chapter, double click on the DMG file we just downloaded to mount it as a unit on the desktop. We open the newly appeared drive, double click on the Hardware folder and drag the Bluetooth Explorer.app app into the Applications folder of the Finder.Still from the Applications folder, we double-click on Bluetooth Explorer, then go to the top Tools menu and select Audio Options . A new window will open, where we can manage every aspect of the audio transmission codecs for Bluetooth.
If our headphones are certified for aptX, we check the entry Force the use of aptX (or Force use of aptX), so as to have the certainty of exploiting the maximum audio quality when we connect the headphones. If instead we have headphones that support AAC, check the items Enable AAC ( Enable AAC ) and AAC CBR and change the AAC Bitrate bar up to the maximum, so as to obtain a superior audio quality with any type of song or musical genre.
At the end of the modifications, simply press the Close or Close button at the bottom right; to take advantage of the new codec set, simply turn off and on the Mac's Bluetooth module (using the appropriate icon at the top right) or turn off and on the Bluetooth headphones in use. The next time the headphones are used, they will use the best audio codec (we can check them at any time by following the instructions in the previous chapter).
These changes do not prevent the use of the SBC codec, always available for compatibility . If we have Bluetooth headphones but we don't know if they support the best codecs, let's test with aptX and AAC and check their actual use; in case of problems or incompatibility SBC will always be used and the changes we will make will be ignored.
NOTE : to be sure of using AAC or aptX, we only choose headphones or earphones with Bluetooth 4.2 or higher support.
Conclusions
Even if the Mac looks like a "perfect and infallible machine", it could make some mistakes, especially in choosing the right codec to use for our headphones: following the steps of this guide we will be able to remedy it, forcing the Mac to use the AAC or aptX codecs (the best) when we connect our new Bluetooth headphones.If we don't know which AAC or aptX headphones to choose, please read the tips in our guide on How to choose quality wireless headphones for PC or TV .
If, on the other hand, our headphones are compatible but the Mac's Bluetooth module lacks support for AAC and aptX, we can remedy this by placing a Bluetooth adapter, such as those recommended in our guide on how to Add Bluetooth to your PC with an adapter .
