The PreSonus Eris MTM E44 Studio Monitor is a bi-amped active studio monitor which features two 4.5 inch woven Kevlar low frequency drivers paired with a single 1.5 inch silk dome tweeter for a balanced and clear sound. Also featuring balanced and unbalanced inputs low cut filter acoustic environment controls and the ability to be used horizontally or vertically the Eris MTM E44 is a high performance studio monitor designed by professionals for professionals.