It seems like back in the mists of time(like three or four years ago)the Big Guy himself while talking about speaker in-house testing used a very short ammount of time as sufficient to assure a good test. Something like a half hour or so on a new speaker. And that may even be longer than absolutely necessary.(or maybe shorter; not sure, but I am sure it wasen't over an hour and a half. Certainly not in days or weeks-or even longer)