You can do this by wearing your helmet and positioning each speaker position against your left and right ear. Have a friend help mark the positions of the Velcro mounting part (this is the opposite end of the speaker boom) on the side of your helmet with a piece of tape or blu tack. Mount the 2 pieces of rectangle (6cm long) Dual Lock Velcros. The 6cm long Velcro provides you with adequate freedom to adjust the speakers’ position forwards or backwards to your preference.