Has anyone tried a rubberized coating on older Klipsch tweeters?


I’m restoring my RF-3 ll speakers. They are VERY bright compared to my RP-600M pair. I’m thinking of trying a rubberized coating on the surface of the horns, any thoughts?
aburnhamuu
I bought sheets of dampening material used for sound proofing autos and placed it all over the exterior of the horns. I found the results pleasing. Toned down the harshness of the highs. 
Not tweeters, but I have used a product similar to dynamat,  peel-off rubber like sheets meant for this purpose on the outside of the horns on my Epic CF-4's. I did 2 layers and it was effective, but I wasn't having an issue with brightness, I just wanted to make it more dead, and to compensate for the fact that it's plastic, not thicker wood.  
I have used Dynamat on the outside of the horns in some of my Klipsch Heresy speakers.  I'm not sure I'd bother with the RF-3s.  I'd encourage you to move to the Heritage line or see if you can find some second hand Epic (CF-X) or Legend (KLF-XX) series speakers if you want better sound quality and like the Klipsch sound.  Bob Crites sells replacement tweeters for Klipsch speakers that are less fatiguing, but I don't think he carries anything for the "Reference" line.  
Thanks, I own a great pair of Quartets I have upgraded with titanium drivers mid and tweet, more sound absorbing in the cabinets and rebuilt E2 crossovers parts for the Quartets. I did Dynamat the Tractrix horns and the woofer and passive frames. I just really like my old RF-3 lls. 
I've always wanted to try some Quartets out.  The RF speakers aren't bad by any means.  I still have a pair of RF-3 I in my home theater setup and also a pair of RF-5.  I've owned RF-7, RF-3 II, and RF-82 II also.
Thanks for the mention, tomic. The horns on the RF3, and series 2, handle much of the midrange as well as the treble, as they are a 2 way, based on the crossover point to the woofers. Dynamat is a great material to use, but some of my clients wanted to do it a bit less expensive, so I used Peel and Seal, a roofing repair tape, found at Lowes and the HD. There are others you can use as well. IME, every horn, whether metal, aluminum or a poly material, gives the listener a smoother, more relaxed, less colored, cleaner, with greater detail, and a more dynamic presentation, when properly damped. Been damping horns for 50 years ( early on, I used clay, and mortite ). The RF3II is worthwhile, as long as you like them. Do the same as you did with your Quartets. Enjoy !, and be well, all.