A few years ago, I gave a friend a pair of Leak Sandwich 150 speakers and a Kenwood KA-3500 integrated. They were to replace his old, out of commission amp and a pair of likewise Pioneer HPM60's. Those leak speakers were the nicest sounding, non-floor standing speakers I had. His intent was to play music in the room he had setup with his salt water aquariums when he spent time watching his fish. Quite cool actually.
But then his rap loving, bong sucking twin twenty-something year old sons appropriated the stereo and destroyed it. I was not pleased. His response was something like "Whattaya gonna do, boys will be boys".
He wouldn't say but that made me strongly believe that's what happened to his old amp and speakers.
The sandwich construction of those Leak woofer cones was intriguing. A styrofoam wafer sandwiched between two sheets of aluminum "foil". Online, I saw old info showing/stating a standing person putting their whole weight on the apex of the cone and not crushing it. The analogy given was pressing an egg end to end, between both hands without the shell breaking.