XLR Volume Pot - for dedicated Sub amp

Hello,
I have a preamp with 2 pairs of outputs. Looking to use one pair feeding a dedicated amp to power passive subwoofers.

Here's the catch - I want to adjust the gain feeding into the amp so I can dial in the added bass from these passive subwoofers relative to bass content in the music

I was going to DIY a small aluminum case having a pair of XLR inputs and a pair of XLR outputs.

I prefer a stereo pot.

What type of XLR pot do I use to adjust signal gain for the Emotiva XPA-200 amp? I see some pots have K - Ohms. What do value should I use?
Can you mention brand, model #, website?

Thank you