I documented the whole process after 20 hour increments and was taken back by the up and down changes? After I received my second pair, I listened for an hour and put them down to rock and roll and only peeked in every 20 hours. For me the magic number was between 200-250 hours to level out. The HFI-780, PRO2500 and HFI-2200 went through the most significant "waves" during the process.
Of course YMMV, but most importantly if you don't like the base signature of the phone, burn-in will not transform them into something else, just refine them when it's all said and done.
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