 This cost-cutting approach produced recordings with a very limited dynamic range and generally inferior sound.In either case, because of the grain structure of the metal and its resistance to the side-to-side motions of the recording stylus, significant surface noise was inherent and the high-frequency signal content was heavily attenuated.The recording had to be played back with a fiber needle such as cut and pointed bamboo or a plant thorn, as an ordinary steel needle in a typical heavy pickup would severely damage the soft aluminum surface.