I received my Grado 225's yesterday and already had to do my first mod. Turns out that my head is to small for them, so this morning I took a ride down to Home Depot and bought some Rubber Foam WeatherSeal with an adhesive back (3/4"w, 7/17t", 10'l). Went home and cut off about a 5in. strip and stuck it to the bottom of the headband. Now they fit and sound great. The rubber foam is awesome because it adds some cushion for the top of the head, but the surface of it keeps the headphones from sliding around.