Hi everybody!
The technician solved the clue...!!! As the woofer is VERY heavy, the rear aluminium part of the basket pends inside, charging the entire chassis during the shipping. A little bump on the floor by an uncare operator is sufficient to broke the rear basket of the woofer, "sucking" the external membrane inside, as actually happened to my loudspeaker. No objects or ghosts inside... []
In conclusion, as proposed in a previous post, I suggest to ask for a separate shipping (woofer + chassis) assembling everything at home or elsewhere.... to be sure of preserving the integrity.
Obviously the assistance has already ordered my new woofer to the MPI, and I will have my RC-64 back in a few days without any charge.[]
Hope to have been useful...
Ciao
babbiorsi