I have been running the upgrade PR's in my ST- R's previously and just swapped them with originals that were in the SE's, figuring they would possibly make the difference, but no.
There was a lot more of the batting insulation within the cabinets of the SE's than are in my Super Towers too I removed some of the extra while doing the PR switch thinking that might help as well.
I was expecting a much higher level of performance out of the SE's, it's frustrating.