Ipod Classic EQ

In 2023 I am still using my iPod classic 7th generation, but I wonder if there is a way to manually modify the equalizer, since in the settings there are only presets, and I am looking for the bass of the songs to be heavy, at the time of putting some preset this is distorted, and that I want to be able to modify it, currently I use the rockbox firmware since in this I can modify the equalizer, I would like to know if there is a way to change the equalizer in the iPod OS without having to use rockbox to have to listen to my music.