Speaker cables are often available as "pure" copper cables, although they only have a very thin layer of copper. This is particularly true for so-called "CCA" copper cables (aluminum core with a thin copper coating) or "CCS copper" (steel cables with a thin copper coating). These cables have significantly poorer data transmission properties compared to OFC copper cables. Generally, the longer the speaker cable, the greater the power loss, but this only manifests itself in 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 installation).