JP13 RCA output attenuated by bass knob?

Currently have a JP95 running whole system. Looking to add in a JP13 to add 2 more subs at about the same power level.   Can i run source to the 13 first and use the RCA output for signal to the 95 sub channel?   NOT, looking to strap them.   If so, does the remote bass knob also control (attenuate) the signal out of the 13 to the 95? Or do I need to start planning an inline RCA bass knob.