Radio is special item. You can play your own music from mod file.
How to add your music?
1.Install Auda city.
2.Inport your sound.
3.Export your sound as (record1-4.ogg example record3.ogg)
4.Open mod archive as WinRar
5.Go to assets\explode_now\sounds
6.Grab your ogg file into this folder (replace files)
7.Get "Home party" achievement
Remember if you are playing on server with NWD your client maybe crash!