Okay i don't know i can explain that because my english skill is so limited, english is not my mother tongue. I am so sorry. Please can someone explain that for pjyi??? according to my experience, to reduce few dB upper 3-5 kHz can kill brightness. I often use Behringer DEQ2496 and iTunes software EQ and FFT Plot(iOS app, real time sound frequent analyzer) is good for simplified sound measurement.