3CX Android App Beta now adds Google’s AAudio API as an added alternative to the commonly used OpenSL (Sound Library). The 3CX App has so far used OpenSL which is still functional and widely used. However, following Google’s recommendation to replace OpenSL with the new de facto standard AAudio API, we have now included it as an automatic option.

We Need Your Help

We collected the top three audio issues experienced by our customers, namely: echo, occasional 1-way audio (despite perfect network conditions), and low volume. From our preliminary tests, it appears that when AAudio is selected, the sound quality greatly improves and the volume is notably higher. However, developer adoption on this API is still very slow, and with such a large number of phone models and Android OS versions, testing it is a challenge. We need help from the 3CX Android Community to do this.

This Beta allows you to select the type of audio API.

Select AAudio API

  • Click on Settings > Advanced and tap Audio Subsystem API.
  • Change to "Automatic" and make/receive a call.
  • Check Echo, Volume and that you have 2-way audio.
  • Note: might conflict with Car/Bluetooth Support (Telecom API).

How it Works and What to Expect

  1. By default, the option is set to OpenSL. Audio behavior and quality remain unchanged.
  2. If you switch to Automatic, Android OS will handle the decision process as to which API to use depending on what the phone supports. (Old phones use OpenSL while the majority of modern phones tend to choose AAudio). You can gauge whether there is an improvement or not by switching to Automatic.
  3. To check which API Android OS is selected, tap on the Network Quality indicator during an active call. You will see a statistic page.
    3CX Statistics Tab
  4. Here you can see which API is in use. You can also view other information such as Phone and App version, quality %, call duration, and all the input and output audio devices.

Known Issues

  • Users on Android 10 who are unable to answer calls without unlocking the phone, may have an issue with the lock screen interaction. To resolve this, uninstall the app, restart the phone, and reinstall the app again. This is caused by Android 10 internal settings not set correctly, due to the recent Android 10 migration.

How to Try it

Join the 3CX Beta Program and download the new Android Beta app through Google Play Store.

Give us your feedback via the dedicated community forum. Please leave your comments, including your Phone model, Android OS, which API was selected and tell us whether your telephony experience was better or not. (You can take a screenshot of the network quality indicator because it contains everything we would need to provide analysis).

View the complete change log.