I have an 875 Q also - I finally used the taper stitch feature - keep in mind I have never had a class - this is my first computerized machine - I have owned it for less than a year. Ok - if you are doing decorative stitches (for instance I did some satin stitches on applique) the taper can be adjusted to 30, 45 or 60 degrees so when you come to an inside corner or outside - it will bring the stitches down so you don't have this big gobs of stitches overlapping each other. You set it on your machine then when you need it you hit a button (I think the reverse button - I don't remember) and it automatically takes care of it.
Ok - mine does not make loud sounds - except when I don't have it threaded right - then I know instantly what is wrong. Hope this helps. Play with your machine it does many things.