Well...in the context you are quoting, I would define midbass as the upper bass frequencies. That means that if you have poor midbass, you won't get as much "punch" in the drum kicks in the music, and such. If you have very good midbass, you will feel it in your chest. This is different than low bass, as midbass is not handled by a sub. Midbass usually goes to about 80-100 hz. Below that is true bass.replied .. whats midbass ?