In terms of 'Burning in' I think its of the view that you listen to your music at an acceptable level over a period time, for example 20hrs. Anything between 100 - 200hrs is what most audiophiles would recommend for your earphones/cables to be properly 'burned in'.
Its like buying a Porsche/Ferrari/Lamborghini/Bugatti for instance. You dont drive at 95% output as soon as you take it out the showroom. No, you treat it like a lady, with respect,and gentleness and the same goes for your phones, treat them with respect, and gentleness and you will be rewarded with many years of pleasure.