Noise inside speaker cabinet when moving ?

I recently acquired a pair of LSA 1 Statement speakers at a fair enough price on an audio mart website. We struck the deal , the speakers were shipped to me . I received them and began the process of removing them from the shipping box. Only to see they were put in there upside down , which was a bit odd and unusual to say the least. While in the process of turning both of the speakers right side up , I noticed that each one had a distinctive mechanical movement noise in doing so. Hooked up both speakers to my audio rig stack and they seem to play quite well. Nothing I can hear that might suggest internal damage or broken parts etc inside the speaker cabinet. What could be causing this noise ?. I initially thought , though not an expert on speaker construction by any means, it could be some part of the internal parts righting itself after being turned upside down like that by the seller. Is this a common occurrence for some bookshelf speakers to any degree. Or even speakers in general. Again the speakers sound and work quite fine. It would be one thing if just a single speaker had this issue , if we can call it that, but both of them.

Any ideas as to what could have caused this noise when turning them right side up?