https://www.musical-u.com/learn/fix-the-mix-dont-let-a-muddy-sound-ruin-your-tracks/
Don’t depend on trial-and-error!
Train your ears to hear frequency.
In the studio, frequency training seems almost intuitive.
You may not know why your track sounds better with some deep bass, an added high-pitched synthesizer, or even a thinner texture, but you do know that your music can go from average to awesome after a few minor tweaks.
Learn how to improve your mix below as we take a simple music sketch and improve it using common frequency-mixing tricks.
Test your ear training skills. Listen for octaves, frequency, pitch and texture.
Then use the great tips from this article in your own music.