I've read his sound mix is shit on top of the line IMAX too. Plenty of complaints since the days of The Dark Knight, He is just high on his own supply and can't admit that he is shit at sound mixing dialogue. That or some contractor lied to him when they built whatever he mixes on.
He specifically declines to have it mixed well on stereo because he doesn't think we should be watching his movies with anything but the most expensive speakers