Hi Charlie,Wow! That is an interesting cone design!
Looks sort of like a Manger, which is designed to allow the cone to flex on purpose, so that some of the mass is decoupled at high frequency. This allows one cone to provide a large surface area for LF and MF and a smaller one with less moving mass at HF. Most full range or extended range transducers use a sort of controlled breakup mode to do this. Altec made the BiFlex with the same idea in mind.
Controlled cone flex
Manger diaphragm
So I wonder if that was the idea behind the unusual cone shape of the RCA LC-1B speakers too.
Thanks for the post!
Wayne