My gosh this was a substantial upgrade. Integrated probably blended all your frequencies together versus separates that are substantially better.
My guess is it’s bringing out the speakers you have maybe in a different way. Maybe better maybe worse but your hearing them differently.
And the subwoofers probably need a lot of tuning because if they’re off probably the trebles gonna be impacted. I have gain settings on my amplifiers and when I adjusted them it reduced the trouble sound from the speakers. But I would avoid adjusting your treble so aggressively because you’ve really reduced it and I would focus on other areas.
Basically you’re hearing your speakers differently because the components you have are outstanding. I’m not a big fan of bell tweeters because they are very revealing and kind of annoying. I don’t even like the diamond tweeters I use on my Bowers speakers. So I’m thinking about sonus faber. Sometimes revealing may not be such a good idea for comfortable listening.
Try different music because now you’re hearing the recording quality a lot better and because of this I am now very disturbed by the poor quality of most of the things I’m hearing because the engineers didn’t do a very good job sadly but I live with it but it does make even a bad recording sound better it’s just I’m noticing them more. Which is why revealing speakers can have their problems.
Final point, 90 dB is very very loud and approaches a danger zone and I'm not sure how big your room is. I would lower the volume and get used to lower volumes for your hearing health. You should be able to handle less volume now that you have a more revealing system.