Well, I did a thing.
I took one of the pair of beasts apart, put damping in the cabinet, replaced the crossover and the body of the horn, and tilted the cabinet back a few degrees. Then I spent the next several days switching L/R (to the annoyance of the SO and amusement of my kids). Left one bone stock and the other modded to compare.
Interesting note, when I cracked it open, the cabinet has no damping except for a folded over layer of polyester batting that extends over the back of the cabinet from the top to about the bottom of the woofer. Cab bracing was non existent except for some triangular blocks between the sides and front back (and top and bottom) panels. Interesting. I thought about adding some braces, then didn't. The stock wires in the cab are THIN! I thought about replacing them, then did not. Laziness (and $) ruled the day.
Specifics:
1) 5 SF of 80mill dynamat, generic from amazon. Focused on the back panel but also some on the sealed back of the midrange and the horn body.
2) some zip stretch tape, a 40mil product for construction, has some weight to it, used for gaskets around the drivers and some on the horn body.
3) Sonic barrier from Parts Express. 3/4 inch, freaking expensive, 1 sheet
4) Acoustistuff from Parts Express, 1 pound
5) Crossover: Uxcell 180W 3-way from amazon. 2 for $26... more on that.
6) 1.5" rubber feet at the front of the base, to give me a tilt.
7) Goldwood 85/8 midrange driver replacement
8) Old bath mat glued to the top and bottom. What the hell.
Thoughts after infinite L/R balance switching and making funny faces:
1) My soldering sucks. But I think it was functional. Getting better.
3) First audio impression: This sucks. But, after letting the midrange break in for 2 days, it opened up, A LOT. The whole thing is more midrange forward now.
4) Everything sounds much more controlled. No more small echoes, much better clarity.
5) Seems to have lost some overall sensitivity, makes sense with all the crap in the box, I guess. Except for the midrange - the new Goldwood's 96db sensitivity is legit.
6) The sucker is heavier than hell now. I could carry the unmoved box with some groaning. Now I ask for help on the modded one.
7) Bass is noticeably reduced. At first I had the acoustistuff low in the box, and I noticed it was blocking the ports. I cracked it back open (my new gaskets make that a pain now), hot glued the new fill higher on the back wall behind the drivers, and as far as I could tell, it didn't make much of a difference. Not sure if the reduced bass is a crossover thing, or all the damping, or the new tilt resulting in floor bounce phase-cancel stuff. Or maybe the new midrange just dominating everything else.
8) The tilt looks really cool. Amazing what it does to fight the big, uninteresting, black monkey coffin rectangle factor. It might also help with the midrange audibility at standing height.
Overall, qualitatively (to my ears) the speaker is improved, much sweeter, more discernible vocals, but the loss of low end is disturbing. The changes are not night and day. The unmodded speaker is near a corner, so I am sure the room effects are not helping. Too many variables! Lost a driver screw along the way. Lowes has #8 SS sheet metal screws, pan-head that seem to match perfectly.
Next Steps:
1) I plan to do the exact mod on the other cab, but leave the crossover intact. I will see how the new, cheap crossover affects the bass output, and overall sound. Pretty sure the second one will take 1/2 the time. Less, because of leaving the original crossover.
2) I am recovering the screens with some fender oxblood amp grill cloth. Trying to get a little more sheer to show a hint of the red woofer, add interest factor, maybe a little more acoustically transparent at the upper end. The fabric from Mojotone drops tomorrow.
All in all, a fun project dumping $250 into speakers I paid $200 for the pair on Craigslist. For $450 could I have gotten something "nicer?" Yep. I saw some Mach ones in that price range recently, and even some AR 90s that tickled my fancy (big, interesting-looking speakers). But, I am making the Bics my own, and enjoying the process.
A few photos from the process. You can see the old vs new crossover (new in the bag).