Matt, I finally looked at the auction. Those look like 2As not 2Bs. They have the 2A cabinet style. The difference is a different driver complement and crossover config. It's not a bad thing, the drivers in the 2As are used in various SDA models including my 1Cs. However, during the model rollovers sometimes the newer rev was put into the older cabinet. If these have the pin/blade interconnect they are 2Bs, if it's blade/blade they are 2As and cannot be upgraded to the TL version and must have common ground amps (1A-1 isophase modded cable won't work. This IC mod was/is offered by Polk for their late model revs). Depending on the amp, you might be able to strap the negative grounds (on the amp terminals) of a non common ground amp and have no problems, but you'll have check with the manufacturer.
About the tweeter, it's the SL2000. You've probably read all about Polk's silk replacement the RDO-194-1 and how it crushes the SL2000. I've done the replacments and here's my take. The original SL2000 had a 5db hump at 13khz. As they age, they can get a little hissy, some more than others, but I found them a pretty darned good tweeter. The RDOs are better, controlled, no sibilance after breakin (and it's noticeable at first). Initially, I thought them a tad boring in comparison, then after awhile, I had no issues with them. When I bought a second pair of SDAs, I replaced the tweets again, but I listened to the 2000s for a few days. After the 2nd day, I found them annoying. As soon as the replacements came in I popped them in. So, my advice is to keep them stock for awhile and judge their strengths and notice weakness. The tweeters are a nice upgrade. Not essential, but only one person that I know doesn't prefer the silks.
