How do I pan audio in iOS? I've successfully used AVAudioPlayer's pan to work but only when connected to headphones/external speakers.
I have an audio file with a voice singing a melody in one channel and piano playing the same melody in the other channel. When I set pan to -1.0 and use headphones/external speakers, I get the correct behavior: only the voice or piano can be heard performing the melody, but not both. However, without anything plugged in (using the phone's speakers), I hear both channels regardless of whatever value I set for the pan.
I've attached the mp3 I used: https://drive.google.com/open?id=1BYUymcBU8mfz7PVeCF2446xZw5fU4e3G
