Can I use a JX-S900 Y/C separated I/O to run two subwoofers out of same reciever??

Yes, on two conditions:

1) the JX-S900 needs to be a proper matrix switcher. It has to have the ability to route 1 input to more than one output.

2) the sub signals need to be low level RCA/phono, and not high level speaker wire connections. That's not just about the type of connector. It's about the signal going through those wires. A low level RCA/phono sub connection conducts a maximum 0.7 Volt. A speaker wire connection can transmit 30 Volts! If you put 30 Volts in to a line level switching device such as the JX0S900 you'll fry it.

Provided that the above two criteriia are both met, then yes it will work.

• Connect the AV receiver's sub out to Source 1 - white RCA phono.

• Connect the two subs mono LFE Left input (white RCA) or the single black RCA/phono inputs to the JVC's outputs 1 and 2 - white RCA/phono.

• Set the source routing: input 1 goes to output 1 and 2