I may have your description wrong, but I am assuming that you basically need to make this table play sound right?
Depending on how mechanical you want to get, there are several ways to go about this. Personally, I think you should ideate on the table, as it could be much more interesting. The tall grey area could become a ‘cone’ by creating a way to float it (surface area like that would only require a short xmax for decent frequency reproduction) and hook it to a servo driven motor. Easier way to do it would be to create a transmission line out of the internal space. You would be surprised what a small driver can reproduce (check out the silverline preludes).