Oh brother, I shouldn't be, and don't mean to be critical, but you have some
serious catching up to do!

Just out of curiosity, what did you think was making that sound, or was it simly something you never noticed before?
I got my first rotating speaker in 1979, because I knew that's what provided all those delicious tones like Badge, No Matter What, Casey Jones, and especially Foot in Coldwater's singular hit "Make me Do Anything You Want". Once you've played through one it's hard to settle for anything less.