Thanks for these replies. The points on room placement/treatment are well taken. I've spent about 15 hours so far experimenting with room placement and floor decoupling. Have hit a plateau due to room limitations, so I thought I'd work on the cables some more while continuing to work with placement.
The living room is pretty limited in terms of what can be done. It's 18'L x 12'W x 8'H, with suspended hardwood floors throughout. Normally I listen across the width, and the speakers need to be close to the wall in order to have space to move about in the room. Their normal position is about 1' from the wall, which is noticeably better than, say, 6" from the wall, while I sit on a couch against the opposite wall. I can move the speakers a couple feet closer when I want to do some more focused listening, and it's OK as long as the volume is not too much. It is certainly better than 1' from the wall. No matter how far the speakers are across the width, though, the wall tends to pick up sound and artificially amplify it as the volume increases.
For more critical listening, on a few occasions I've cleared the furniture out of the room and put the stereo at the end, centered on the long axis, with distances of 3-4' from the back wall and minimum 2' from the side walls, while the chair I sit in is a good 4-5' from the back wall to mitigate reflection around my ears. The speakers being near the corners, even at a distance of a few feet, is definitely not optimal, but soundstage/imaging and overall tonal accuracy is better than listening across the width of the room. I've found that the speakers sound best so far when 4' from the back wall and a bit closer together, say with about 5' separating them. Moving them in or out an inch or two at a time and adjusting the toe-in angle results in subtle improvements.
At first, in all of these placement configurations, the room tended to pick up mechanical vibrations and artificially reflect/amplify them to the point I could even feel individual waves in my feet as they moved along the floor. In order to reduce mechanical interference, since the speakers way 110lbs. each, I removed the brass feet and put the spikes in aluminum receiving cups (I'm on a tight budget). WOW -- what a difference! Accuracy improved across the board, and instruments sounded way more realistic right away, with a dramatic improvement in bass extension and accuracy. On a subsequent listening, I put Magic Sliders under the aluminum cups, and the improvement was very noticeable yet again. I'm actually thinking of replacing the Magic Sliders with felt pads, since on my dining chairs they have even less friction than the chairs with the sliders.
While I've been happy with these improvements, there is still more work to do. I'm intrigued with some of the decoupling products at Herbie's and might try to save up the $200 for a set of those.
I've been taking notes in a spreadsheet, using the same set of pieces to test various aspects of the music I enjoy:
* Amy Winehouse -- "Me & Mr. Jones," for that "big" 50s sound and female vocals
* Miles Davis -- "So What," for bass accuracy and realism, plus harmonic range of the ensemble, sound stage
* G. Love and Special Sauce -- "Stepping Stone," for guitar and bass realism, percussion musicality, and FUN!
* Sonic Youth -- "Schizophrenia," for percussion musicality and glorious guitar noise
* The Cars -- "Just What I Needed," for percussion musicality, precise guitar crunch, general tightness of the band and crispness of the recording
* Beethoven -- 9th symphony, for orchestration range, sound stage, instrument separation, male and female vocals.
* Radio Head's album In Rainbows and Beck's Morning Phase, which are just phenomenally well recorded and present a huge frequency range.
Granted, a lot of these recordings are bass heavy, but that's kind of the point. I don't find bass to be overwhelming in classical symphony, and in fact find these speakers to excel with that genre.
Didn't intend to write this much. Anyway, this all started when I traded in my old JM Lab Chorus 706 bookshelf speakers because I wanted something would not pull back with larger orchestration or could sound just a little bigger for older rock music.
The Paradigms certainly make up for the shortcomings of those tiny JM Labs, but are not quite as accurate in the mids and highs. In general I really like the Paradigms, but they might have been overkill given the size of the room. And due to our living habits, it's really not feasible to leave them set up across the length of the room, so I have to move everything all over again each time I want to try that way of testing, and inconsistency is a real problem.
The Paradigms are simply too big for the room, I think. But before I trade them in for something smaller/more appropriate, I want to try and learn as much as I can from them, since they have many more features than my old ones. Wiring changes are part of that process too.