Technically- No, but it also depends on what songs you are listening. You can also try changing the settings on the equalizer on the audio application you are using on the phone... I know you can change the equalizer on Apple music and Spotify apps.
This also happened to me on a pair if Slims.. I actually took them apart, took out the metal screen, cleaned it out with a qtip and alcohol, and reassembled them.. sounded fine after I did that.
If none of that works, contact anker if you still have warranty on them