Cordial Knowledge Base

Skin Effect

For some time rumor has it that the "sound" of a cable also depends on the so-called skin effect. We have already informed you - see shielding - about magnetic fields around a conductor. When current flows, a magnetic field will also form inside a conductor. With direct current, the current density is the same over the entire cross-section. With alternating current, however, the magnetic field changes periodically, thus generating eddy currents within the conductor resulting in power losses. The electrons located in the middle of the conductor are exposed to a stronger magnetic field than the electrons further out. A resistance is created (see last week). This practically reduces the cross-section of the conductor and the current flows quasi only at the outer surface of the conductor, i.e. quasi on the skin. Hence the name, skin effect.

In the analog audio sector, however, the skin effect doesn’t carry great weight because it depends on the frequency. Only from 50 kHz onwards with a 0.5mm² conductor this skin effect will be noticeable at all. For example, the resistance only increases by 0.2% at 20 kHz, and by 20% at 200 kHz.

Therefore, manufacturers use individual wires insulated from each other, silver-plated conductors or waveguides in the high frequency ranges because common stranded conductors do not reduce the skin effect as they are not isolated from each other. They only improve the flexibility of the cable. All in all, in the field of audio technology the skin effect does not have any significant consequences and can safely be ignored.