Well I placed them on top of the Sonys so that they would be in the same lateral position for imaging, etc. They are just as far from the back of the wall as the Sonys. The Sonys are on the floor but they are on carpet.How far are they from the wall in back of them?
Looks like it may be good for imaging but not so good for bass.
Have you been using the Sonys on the floor? Maybe they are getting bass reinforcement from the floor.
If so, maybe try the Polks on the floor to see if the bass improves. You know, apples to apples.
Corner placement also would reinforce the bass at possible loss of imaging.
As mentioned, they might not be the best match with your Sherwood.
You've got serious issues if the caps are measured in megafarads. I believe they're measured in microfarads, so check again. The symbol for micro is a "μ", where mega is a "M". Either way, the caps are 27 years old and you have no idea how hard they've been driven. They may be due for a replacement.I can't tell if the caps need to be replaced (they are out of range on my multimeter, as I think they are on the order of 8 megafarads)