Hearing background sounds more vividly at low to (somewhere around) medium volume is a classic effect of greater dynamic range compression, IME. I am not saying that is what you are experiencing @TheIceman93 . This is the just the first thing I think of when I hear that description. Unless we can compare the exact same mastering with and without MQA, I don't think we will really learn anything. I don't know if the tools (comparing EAC logs or null testing) to verify that the mastering is identical (or not) will apply with MQA involved.