We recently reported that despite the Xperia Z2 having stereo speakers, it does not take advantage of them when it comes to incoming calls, notifications or when using the speakerphone. Well thanks to a new mod by XDA member olokos, you can enable stereo speaker functionality for all of the above.
The mod also includes a headphone sound boost too. You can install the mod via recovery (your Xperia Z2 will need to be rooted). Sounds like a useful feature, however we wonder whether Sony plans to include something similar at some point down the line. The necessary downloads can be found over at XDA.