Normally on Sony Xperia devices, the FM radio can’t be used without the default headphones. That is because your ‘cans are used as an antenna to improve the signal, but this doesn’t mean that FM radio itself can’t work without headphones. Sony users can already modify their FM application using a smali tutorial by XDA Recognized Contributor DaRk-L0rD. However, smali is not the easiest language. And to use it with confidence, you need to know some bits of programming. Thankfully, if you want to use your FM radio without the included headphones, there is now an easier way of doing it.
The solution was presented by XDA Forum Member thermatk, who transformed the aforementioned guide into an Xposed module. The module is exactly the same fix as the one described in the guide, but it’s easier to install. As such, the modification is pretty simple, but does its job as intended and should work with all FM radio applications on Jelly Bean-powered Sony Xperia devices. To use this module properly, the Xposed Framework must be installed and your phone must obviously be rooted.