I've lifted this from audio.stackexchange.com where it hasn't seen a lot of discussion. It's a question that interests me though so I thought I'd post it here, verbatim, and see what comes of it.
Some speaker manufacturers† claim that one must "break in" their speakers for a given period of time before they sound optimal. This sounds fishy to me. Is there any reason speakers should need a "break in" period?
Some resources on the web seem to argue both sides of this question convincingly:
† For example: Paradigm recommends "several hours"
Over at audio.stackexchange it's been decided that, 'Yes, speakers do require a break-in period.'