Midrange Increasingly Harsh

Way more knowledge at this site and more manufacturers available than here.

https://www.whatsbestforum.com/forums/

I concur that tubes are the place to start looking, 5 years is a fairly long time for power tubes if you're listening with any frequency.

The cause of your issue can be anything in the chain from start to finish, including the source material, cables, seating location and the room itself. All you can do is replace one item at a time and listen to see if the problem has gone away. Do you have friends or a friendly dealer, that can loan you gear to eliminate each piece in your system?

I would start with the speakers, but I wouldn’t be shocked if it turned out to be the room.

I had the same problem with the same source material and it took replacing my speakers to fix it. Even with trim pots on my speakers, I couldn't correctly tone down the shrillness and etch without adversely effecting the adjoining frequency ranges. Good luck with what you try.

All the best,
Nonoise

There’s your answer , I recently finished upgrading a pair of older Klipsch

the capacitors get dryed out  and start loosing their harmonics it just gets worse 

I replace the resistor so with much better quality then the old cement typeresistors which are gritty , and the stock capacitors in most speakers under $15k is nothing special.  I learned upgrades when I owned a Audio store 

go to Humble homemade hifi capacitor test, you should pul a bass driver out and take a picture, if you are lucky the wires from the Xover are just slide on terminals 

where you can remove the Xover ,if not it’s soldered-in place . If you like them and plan on keeping them that’s what I would do first ,upgraded Xovers sound much better then stock parts ,it’s Like going from a stock engine to a Hot rod.