Can speakers sound worse during break-in period?

I purchased a NOS pr of speakers ( I’m not disclosing their name. Not interested in hearing from their haters) and was really liking them before I started to seriously break them in. It seems like after 24 hours they seem to have changed and sound worse, or not as good as they did. Are they just going through changes with some drivers opening up faster than the others? I know there are many components involved in this process and some might be a head of the others. I’m assuming that’s the case and when everything comes together they will sing.
timlub1,745 posts03-25-2020 9:04pm@geoffkait
I would argue that many, if not most of those things mentioned also change during break in. Of course, that may or may not be the intent of your post.

>>>>>Actually I was responding to the statement that any parameter of sound can be measured. I do agree sound characteristics changes during break-in, whether or not these characteristics of the sound can really be measured is a different question.
Time to enjoy the roller coaster ride - play them as much as you can over the next few weeks after which point you'll either love them or hate them.
it took hundreds of hours for my von Schweikerts to settle in....when I first listened I was alarmed but stayed the course. 
So perhaps Woofer compliance is the area of most effect ?
That being said, small difference around 30-40 Hz ? 
Audible... doubt it. How does one design, manufacture, sell, something with the promise of perfection upon burn/break in, and at what time table.
And is there planned obsolescence built in as well ?
Perhaps then the answer is to buy certified second hand. Benefit being if you can.., hear something at it's best or worst. Voila' pay half the grossly exaggerated value at new. 
Eat better, buy an exotic car, travel or stay home listening to music sounding the way you like without all the B.S.