after calibrating my room using Sonarworks Measurement Microphone and Software, the quality of my mixes was in a different realm. Even though my control room is sound-treated, the attached screenshot of the frequency response curve shows, how much my room was off from being linear on all frequencies. To make sure, the measurement was correct, I also measured my room, using a different software from another company: the resulting frequency response curve was almost identical. The quality of my mixes as well as the confidence I have in my mixes improved dramatically.