the only thing that needs a break-in is the ear-brain;
in order for it to be completed as fast as possible one needs to forget the prejudices - we all have some because we're used to one particular set of speakers in a specific room which give a specific kind of sound - and try to listen with an open mind, concentrating only about how true to the original instruments and the recording ambiance the reproduction is; and NOT paying attention to how different they sound compared to the former speakers.
in other words, one needs to listen with a fresh mind, with a blank page.
my $0.03 worth... :-)