The same VGA cable can be used with a variety of supported VGA resolutions, ranging from 320×400px @70 Hz, or 320×480px @60 Hz (12.6 MHz of signal bandwidth) to 1280×1024px (SXGA) @85 Hz (160 MHz) and up to 2048×1536px (QXGA) @85 Hz (388 MHz). There are no standards defining the quality required for each resolution but higher-quality cables typically contain coaxial wiring and insulation that make them thicker. Shorter VGA cables are less likely to introduce significant signal degradation. A good-quality cable should not suffer from signal crosstalk, whereby signals in one wire induce unwanted currents in adjacent wires, or ghosting. Ghosting occurs when impedance mismatches, 75 ohm (Ω) by the specification, cause signals to be reflected. However, ghosting with long cables may be caused by equipment with incorrect signal termination or by passive cable splitters rather than the cables themselves.