Hi Mark, I don't know if your JC-1s are broken in, but mine sure are and no lack of slam here... The comments about the preamp tubes sound valid, and proper positioning and spiking of the speakers are essential... If you're looking for more goosebumps I have 'em... Hope you got a receipt from an authorized Parasound dealer in the event you need service down the road, as there is no warranty otherwise...
Brian Walsh
Brian Walsh