I was reading about optimizing the speakers' output by manipulating the equalizer when I thought of how would I set it up so I tried this method but I'm not sure if this works but it works for me.
First, I create sine wave files of the following frequency: 100hz, 200hz, 400hz, 800hz, 1khz, 2khz, 4khz, 8khz, 12khz, 16khz.
Then, I play each of them and make them equally loud by manipulating the slider for that frequency. Note that our ears aren't sensitive on low or high frequencies. You might be adding more on the left and right side of the equalizer (or reducing those in the middle). In the end, it would probably look like a smiley.
It worked for me. It made the bass sound more pronounced and high pitches became noticeable, unlike before.