Bluesky

Hello,I’m new to the forum and I’m looking for help with my system.I’ve been using rf83s for about ten years and always loved the sound until recently.I’m hearing some distortion or static mostly in vocals and the bass doesn’t seem quite right. This could be my 300wpc amp starting to fail or the speakers.my first question is how can I test my rf83s to see if they are functioning at 100%? I tried a different pair of speakers but they don’t have as much detail so I don’t know if they’re just hiding the problem.this bad sound seems to be noticeable at a very certain frequency but I can’t pinpoint where. I was thinking of replacing the tweeters but that might not help at all and new woofers are not available as far as I can tell. Any simple tests I can do on the speakers? I don’t have another amp to try.