Originally Posted by
StuckInYYZ
That's actually part of the design. The second plug offers a bit of a power boost to the volume. You could probably plug in the two prong and then the airfly after that, that should fix the problem in theory.
Ah. I tested it at home using my phone and a 2-channel amp. Never thought that it would need the second pin because I assumed airplane usage was only one of the use case scenarios (based on their literature). I guess will hang on until the next flight.