I have a pair of EPI 100Vs and I think there is a issue with one of the tweeters. I've narrowed it down to the speakers through trying different sources, headphones, etc. I have a Sansui 551 with the loudness on and treble fairly high. One tweeter is definitely not as loud. The sound is still there, but when I flip the amp to mono and flip the balance, it's not the same. Could it be blown and still be emitting sound? Or is it something else within?