@navyachts : " And would they be on the inside or the outside on the FL/FR speakers? "
With all respect that is a question you don’t need to make due that even if the other gentleman could has the same ML model as you the ROOM and probably the whole system chain linksand his preferences are different ( even the wife, if any. ).
Today subs come with a true advanced DSP electronic/software tool to integrates subs to almost any speaker room/system.
Look, my Velodyne models ( old ones. ) has no those tools and I took 1+ year to achieve where I’am today. I tested/try: behind the speakers, at side of the speakers, back between speakers, front between speakers.
My room is an inverted L shape so one of the speakers has not a near side wall. Finally the Velodyne’s are seated exactly near and in front of each speaker and subs are side firing ( the 15" woofers. ) in between , clearly not an orthodox positions
Btw, phase at 180º .
R.