The construction of a cable has a big impact on the overall quality of the sound. The layout of the conducting wires in a cable determines its characteristics – for example, a cable with parallel conductors will have a high inductance, which is a major cause of interference and distortion to the audio. This can be demonstrated in a common aerial lead – they are designed to pick up electrical ‘noise’. In essence, spiralled wires have lower inductance, giving rise to a cleaner signal. High-end cables have negative and positive conductors spiralled in opposite directions to minimise the electromagnetic fields surrounding each conductor.