Saul, the mid-HI cabs are 2x12 plus a co -axil hf driver. The new system is horizontally laid out. It is all made to fit on top the RX18jnr when laid on its side. Each stack will be 2X RXjnr 1X upper bass cab (1x15) and the mid hi cab which will have the new horn placed in the middle of the cab.
These cabs will also lay across 2 RX18's when stood upright.
Peace and goodwill to all speaker builders