I have this machine. I use the original fmq foot that came with it. No popping or hollow noise at all. In fact I quilted all day today with it and not one thread break or messed up stitch that was the machine's fault. I use Glide thread top and bottom, a bobbin Geni (I take out the bobbin case spring) and Titanium coated topstitch needle size 80/6. It just purrs along easy as can be. I don't use the three hole bar at the top, I buy pass it, I put my thread down the far right hole for a guide only.