Hi all. I have a Yamaha RX-v683 receiver with Kef Q15.2 speakers for my front L/R. For months, my right front speaker has not been receiving audio to the tweeter. I tried troubleshooting by switching the front speakers, and now I have the problem in both fronts. The audio sounds thin, and there is no movement in the speakers when I touch them. Center, surrounds, and Zone 2 speakers are all functioning normally. I have tried recalibrating with YPAO, restoring factory settings, and unplugging everything and replugging. I have also tested the front speakers on another Yamaha receiver and they work perfectly. I have no idea what else to try. Any thoughts? Thanks in advance.