Free Plugin! ToneLib Baxandall EQ
https://tonelib.net/plugins/tl-bax-eq.html
Baxandall EQ is a special type of shelving equalizer developed by English audio engineer Peter J. Baxandall back in 1950. Its shelves have a wide and gentle Q-factor with a greatly minimized phase shift spread over a wide area, which gives them a very transparent and musical sound. This special trait has kept the Baxandall EQ extremely useful in mixing and mastering for well over half a century.
Whether you want to add presence, sparkle, brightness or air to your highs without making them too harsh, or you want to add thickness and weight to your lows but keep them from getting boomy or muddy, Baxandall EQ is the answer.