One more thing to try.......
Hit the Function Button.......
Push either the arrow up or arrow down buttons (just under the data wheel) until you see "Master EQ Type"......
Use the + or - buttons to select one of the 5 different pre-sets. These will drastically change the way the pianos sounds coming from the internal speakers.
I found when the keyboard first came into my store that I heard way to much bass coming from the lower keys and by changing the settings to a different pre-set, I liked the sound much more when playing the piano sound.
George Kaye
Kaye's Music Scene
Reseda, California