OFC is abbreviated from the term Oxygen-Free Copper and is associated with high quality speaker wires because of their excellent conductivity and ductility.
Oxygen-Free Copper (OFC) cables are highly conductive pure copper that is melted under non oxidizing conditions to remove oxygen and unalloyed copper to become pure copper to a grade of at least 99.95% cu and contain no more than 0.03% O2. The OFC ability for electrical conductivity must exceed IACS 100% material rating system.
The melting of copper is performed in several stages until it reaches 99% purity. Then the copper is placed in anodes to be refined electrolytically to a grade of at least 99.95% pure copper. On completion of the aforementioned processes the copper wires can then be classified as oxygen-free copper.
The definition of IACS stands for International Annealed Copper Standard. Copper has been selected as the benchmark standard when comparing the electrical conductivity of metals, and is the measurement standard that has been adopted worldwide.
The pure copper is then used to manufacture speaker cables, such as OFC 99.95% and OFC 99.99% grades. For instance, the speaker cable manufacturers will source pure copper according to known standards respectively, such as C10100 and C10200 standards.
High-fidelity speaker cables are very popular with audiophile enthusiasts since the accuracy of audio signals, are reproduced immensely well with high-fidelity cables. This is why many audiophiles select OFC speaker wires for their preferred high fidelity cabling in audio systems.
There is another metal utilised for speaker wire alongside copper on the market. This is silver which you’ll see occasionally manufactured with both silver and copper incorporated in twin-pairs of OFC speaker leads.
Silver has the highest electrical conductivity and lowest resistance of the metallic family. Hence the electrical signals pass freely along the silver wires mostly unopposed, giving justification to some audiophiles believing that enhanced audio is achieved when using silver speaker wires. Moreover silver wire will be designated for the negative polarity conductor and the copper intended for the positive polarity conductor. However the majority of OFC speaker cables on the market utilise copper for both the negative and positive conductors.
The actual gauge (diameter) of the copper wires is typically referred to using the American Wire Gauge (AWG) measurement system. The AWG measurement system is widely used amongst OFC speaker cable sellers. Furthermore the OFC speaker wires are sold in numerous AWG sizes, such as 22AWG, 18AWG, 16AWG, 13AWG, 11AWG, 9AWG etc.
Manufacturers like SoundLink manufacturer a wide variety of the AWG sizes mentioned previously. SoundLink construct the OFC speaker cables with clear see-through jackets, as well as, in round wire shape and a flat wire shape to neatly fit under carpet. The flat-designed OFC speaker cable can then be laid inside automobiles for their car audio systems.
In conclusion, pure copper OFC speaker wires are very good in transmitting beautiful audio sound to your ears. If you have a nice home theatre system with digital Dolby Digital and high quality speakers then install OFC speaker cables and you’ll be amazed.