The OnkyoEQ-211 M is an audio equalizer designed to enhance sound quality and provide users with control over their listening experience. It features adjustable frequency bands that allow users to tailor audio output to their liking, potentially improving clarity and depth in the sound. Typically, models from Onkyo are known for their attention to detail in sound processing, making them suitable for various audio systems. The EQ-211 M likely includes options for preset equalization settings in addition to manual adjustments, providing versatility for different music genres or listening environments.