I recently decided that I'd replace the woofers in my old RT-10s. I managed to get one woofer and both tweeters replaced near the end of the warranty, but, 7 years later, the older of the two woofers finally gave up the ghost.
I searched ebay for a while, and came very close to purchasing some RT-7s to scavenge the drivers (fyi, these can be found for around $125-165 shipped). I even saw a pair or two of RT-10s on there, but the shipping on those was too high for me to swallow.
So, I eventually decided to replace the woofers with some more readily available drivers. I took all the necessary measurements and talked extensively with the folks at Madisound (http://www.madisound.com/). I eventually settled on the Silver Flute W20RC38-S, which is an 8", 8 ohm, shielded woofer (http://www.madisound.com/catalog/pro...roducts_id=850).
This woofer is a bit larger than the stock woofer, so I had to use a router to increase the size of the hole (if anyone wants more info on the routing procedure, let me know). The folks at Madisound also suggested adding about 4-6 oz of wool to the inside of the cabinet to control bass response/boom (http://www.madisound.com/catalog/pro...roducts_id=772). Unfortunately, I didn't take any photos during the installation (doh!), but I've attached a few of the finished product.
After about 60 hours of break-in, I can report that this woofer is a great replacement for the stock woofers in the RT-10s. Bass extension is solid and a bit more controlled than with the stock woofers (the wool may be playing a part here). Midrange performance is on par with the stock woofers. Unfortunately, I don't have the equipment to take Frequency Response measurements, but I've tried them out with a variety of material...and so far, they've passed with flying colors.
Hope someone finds this info helpful.