Hey Dave,
I think you make a good point about Brian getting up with ZYGI if he wants speakers. Bob is a really good person to work with.
Also, I think you may be onto something with the cables, and perhaps the plinths sitting right on the carpet. Getting mine off the floor did clarify the bottom. And with my HR-1s, going from spikes to gliders was a good move in overall tonal refinement, bottom to top. But this is with brick floors. I really know little of carpet's effects, though I had my 944s on small rugs as an experiment at one point, and spikes were more differentiating.
Cable-wise, I have come to believe the talk, that well designed twisted cables do solve mushiness/smearing, especially in the bass, and remain musical. Bad ones can be a little cold, but so can some solid wires.
When I tried early versions of anticables, they were a little hard, and for me, too warm with big, softish bass. I think they have improved them though....I don't think I would pay whatever the current "sale" price is for my Morrow SP7, but I am really liking them with the MKIV. I was told their SP4 would work fine for my amp and got some to try, but I could hear the lack of bass from too small a wire conglomerate. So he sent me some SP7s without charging more, which brought the bass up, and a pretty nice gesture.
Also, I tried some Virtue Audio speaker cables, and they sound quite good...and inexpensive! Could be worth a trial period if cables seem relevant.
But for what you are describing, if the antis are good in all other areas, the green 3 mm Marigo dots are $35 for 12 at musicdirect or bought direct from Marigo. They are not permanent, and can easily be removed the way I put them on.
http://marigoaudio.com/tuning-dots/I put mine on the flat part where the rubber ring is glued to the cone. They are placed in the flat of the connection, not touching the round flex part of the rubber, or the coated paper part of the cone. They just fit.
You can remove them once or twice and still have the adhesive hold, but best if you can get them right and not have to move them. Once the adhesive stopped working, I have used acid free, removable Elmers glue stick, and it works fine. I think you can send them back to Marigo for 1/2 price replacements too. At least this used to be the case.
This is the method.
I carefully colored the green top with a black sharpy before putting them on making them less conspicuous.
Put one on. I would start with the top driver. [I ended up with three on it and two on the bottom one. I can't recall why, but I must have thought it was more effective soundwise rather than the reverse.] Then listen. If needed, put one on the bottom driver. Then another on the top, and so on. You will hear it when it is too much. Just keep adding as long as it is beneficial. At some point, it sounds off. May be that one or two per driver is enough.
This was a while ago, but when I talked with Ron at Marigo, he said symmetry is not that important, but I like symmetry so used it figuring even with very subtle damping it might be more effective evenly distributed, and perhaps easier on the drivers. I started with the bottom center...then the top center, and when I thought three would be good on the top driver, to test it, I put the 3rd on where it would be 1/3 of the way around from the bottom center one, and liking the sound, I moved the top center one to 1/3.
My plinths are closed on the sides. For the front and back, I found that some rubber and also some sort of dense foam gasket material I had around worked, maybe 1/2 again taller than the plinth space...big enough to have to work it in in compression. I bet caulk backer would work too. I remember Bob saying he thought the rubber floor stuff you use if you stand on concrete all day, the stuff on a roll at Lowes, is decent damping material and might work well to plug the plinth edges.
I just explored and at some point it was clean without too much bass cut at the same time. I focussed more on the back since the back bass buildup tends to be worse. I just looked at the HR-1s and the backs are open just an inch or so, the opening on the outsides. The fronts, I have three openings maybe 1- 1 1/4 each. Who knows what you will find in your setting. Easy to explore anyway.
Hope this helps.
Will