For ambient or sound, use ambient_generic and env_sound.
It didn't work if you fill the sound path wrongly.
Fill the sound with the name of the sound in the "sound" folder, example: "ambient.wav" or if the sound in the other folder in "sound" folder, fill the path. example: "radio/radio1.wav"
Hope it helps.
Correct me if I wrong Mr. Admin.
Thanks,it worked.Btw how do i make it play on loop?I see there's an "Is NOT looped" option in the flags so i guess it should be looped by default?