Not simple to troubleshoot where the problem. Center EQ issue? Processor for some reason?
Break out the tools. Swap speaker to right speaker position. Same issue. Not EQ or processor.
Spectrum analyzer. Yep, dropped like a rock at the crossover frequency for the tweeter.
Pull the tweeter. Yep, no resistance, infinite R. Hunt for tweeter on line. Tampa dealer, dealer in Michigan.
Look for my records when and where I bought it.
Called local dealer on Saturday where I bought it ; too busy, call back Monday. Called Monday, gave all info. Still waiting for a callback.
I guess they have enough other business.
Called JBL, yes they have it in stock; rather expensive vs online. Found in record another dealer I called in the past and the person's name. Yep still working there
have it in stock, price is good and is on the way.
Maybe the abuse over 4 years is cumulative on that tweeter like hearing damage?