this option has been on many an htc device. its not a "problem" and should only be intended for users with hearing deficiencies, not to increase your music and make it better.
this setting CAN and WILL distort music and even voice conversations and should be used with caution EVEN with people with hearing deficiencies.
and ABSOLUTELY UNDER no circumstances should it be used with Beats or any preset audio algorithm!!!!! you are asking for trouble!