Thanks for help I also got an email from klipsch today
This is what i wrote :
"Message: Hello , I have the old RF-82 speakers. Can i mix them with the new RC-62 II ? will it be a good match. (Timbre) ? "
And the answer :
"Hello,
Yes this should work just fine. The newer RC-62 II has a little more presence in the upper mid-range, but given this is your center channel, if anything, it would be more of a benefit.
Thanks,"
So its ok