RTI 6 Nothing from the mid range speaker

Hello I bought these RTI 6 about six months ago. I love them great sound. Recently I have had some problems. I have been going back and forth with this HK recevier The last reciever I got from HK would play fine then I would hear a loud pop sound in the right RTI speaker. Then it went into protect mode. So I tried another R50 speaker in place of the RTI6 same problem. I thought okay has to be the reciever, and returned it once again to HK. And they did the right thing and gave me an upgrade.

I am still waiting for the new reciever, but while I wait I decieded to use my old stereo reciever in it's stead. So I connect the RTI pair to the good ole stanby reciver, and I can barley hear out of the right channel. Now I thinking something is up. I go to the speaker put my ear to it and sure enough the mid-range speaker just pure isn't playing. The left speaker is fine, the right no go, except for the tweeter. so I but the R50 in it's place and it works fine.

So I go to the forum and read that some people have had this problem and that they replace the brass bi-amp conncetor for speaker wire. So I do this with I think 50 guage speaker wire, plug it back into the my trusty reciver, still no sound from the mid-range speaker. Seeing as this speaks to me like a blow cross-over, I consult my brother the Electrical Engenierr. He unscrews the back panel and looks at the cross-over. He is impressed with build of the speaker, especially the binding post, but sees no signs of a burned or blown crossover. I am at a lost. I have been putting together amatuer home theater set-up's for about 8 years now.

The only part that I haven't elminated is the speaker wire, but if that was the problem the R50 wouldn't work. Please Help. I've finally have the Home theater sound I have always wanted. RTI 6 fronts CSI 3 center, and mirage surrounds. Please help my dream come true and help me with the RTI 6 speaker.