Speaker cables are often available as "pure" copper cables, although they only have a very thin layer of copper. This is especially true for so-called "CCA" (copper-clad aluminum) cables or "CCS copper" (steel cables with a thin copper coating). These cables have significantly worse data transmission properties than OFC copper cables. Generally, the longer the speaker cable, the greater the power loss, but this is only noticeable through the strength of the signal at the end of the speaker. Since power loss can be compensated by increasing the cable cross-section, it is advisable to use cables with different cross-sections depending on the cable length, for example, a larger cross-section for the rear speakers in a surround setup.