Using 2 Subwoofers

I second the JL Audio brand recommendation but I think (hear) that bass is stereo, too just like the rest of the spectrum. I use a pair of JL F110's and love the sound. Had one larger sub before these and two are definitely better than one for my system. When I got them I unpackaged them, put them in place, used the auto room optimization, slightly repositioned them once, and was done. Just like that. In my experience with two you can run at a lower level which makes them easier to integrate and avoid common sub issues.

Sidssp,

I am aware of all the tech reasons you're referring to. In my room I can't place the sub in the middle because there's a large aquarium smack in between the speakers (has been for the last 35 years in a number of homes). With a single sub on the left or right I didn't necessarily hear the sub but with stereo subs I DO hear a broader and deeper soundstage particularly with classical music. I "know" the rules but I "experience" the effect of stereo subs-it sounds wonderful.