Hold the bow in one hand and bang the side of the risor with the other and see if you cant here where its coming from . Be gental , all you have to do is tap it . Most likely its an accesory . like your sight , or quiver mount or rest . It maybe that simms string leaches are all thats needed if its string twang . Mathews strings stretch so much they dont make much noise , but aftermarket strings dont so they are louder on the shot .