Correct/ proper setup for utilizing duel subs with a McIntosh C2600 preamp

Hello Everyone,

I wanted to get a better understanding of the "proper" setup for integrating 2 subwoofers into a 2-channel system.

Current gear:
-Preamp: McIntosh C2600
-Amps: Pair of McIntosh MC275s (bridged/ mono)
-Speakers: Vandersteen Quatro Wood CTs
-Subwoofers: REL S/2
-Source: Jay’s CDT3-MK3 transport with Jay’s Audio DAC
-Source: Lumin T1 streamer / Denafrips Venus II DAC

While running only one subwoofer, I’m currently using both the left & right RCA outputs from the "Output 1" of the C2600 to the inputs of the S/2.

I’m now adding a second REL S/2 subwoofer and wanted to know if I should duplicate the above configuration for the second subwoofer using the "Output 2" of the C2600.

Or should I use the Left RCA output of "Output 1" for the left-hand side subwoofer and use the Right RCA output of the "Output 1" for the right-hand subwoofer.

Adding to this, would I be in a better position to use XLR cables for signal to the subwoofers? And in similar connection configuration?

Adding yet another question, based on what I’ve been able to read within prior discussions on utilizing two subs in a system shows that it’s a better strategy/ more accepted to place each of the subs on the "outside" of the main speakers.

Still learning....have lots of questions....I appreciate any advice, guidance, and experiences you can share.