[2018 MacBook Pro, OS 10.13.6; Finale Print Music 2014.5.24; Aria Player v1.872, Aria Engine v1.872 (OS 10 x86); GarageBand 10.3.4]

I can't find a way to suppress or EQ-down certain piercing higher end pipe organ notes; even after exporting aiff audio files into my DAW, I still cannot suppress those piercing notes in my DAW without totally muffling the otherwise majestic sounds of the pipe organ. How can I eliminate or at least reduce the piercing aspect of high notes?