Audio Issue/Feature in Video Playback

I have just picked up on a 'thing' with the video playback on the iPhone 5. It seems that dynamic range compression and/or EQ is applied to the soundtrack of videos. I first noticed it when I was trying to watch a few concert films and noticed that not only was the sound horrendous but during the high volume scenes, it was distorting. I have tested the same movies on an iPhone 4, iPhone 3GS and iPad which don't seem to have this problem/feature.

Has anyone else noticed it? And even better yet, figured out a way to get rid of it?

Additional thoughts:

I have also noticed that when you play music through the loudspeaker, some form of dynamic range compression is also applied to the sound. Personally I think it sounds terrible but I can understand why Apple would have done this. However, it doesn't affect the headphone output signal, thank goodness, SO, I speculate that it could be a bug that when a video is played, the OS isn't recognising that the headphones are no longer a loudspeaker and not bypassing the audio signal, therefore applying the compression to the sound.

Playing the video audio through Bluetooth headphones removes the compression and distortion of the sound track in videos, and that would have been the solution, but now videos no longer play in sync with audio through Bluetooth on the iPhone 5. (Grr.)

Last thing, the new EQ 'Late Night' that adds compression and EQs the sound in the Music app and sounds possibly like the effect that is being applied to video audio output.