Bi-wiring is a means of connecting a loudspeaker to an audio amplifier, primarily used in Hi-fi equipment. Normally, a single cord (two conductors) runs from the amplifier output to the terminals at the loudspeaker housing. From this point, connections are made to the loudspeaker elements - most often through crossover networks. In bi-wiring, two cords are run from the amplifier output to the speaker cabinet - one to the high frequency or tweeter element and one to the low frequency element (through their respective crossover networks). It has been suggested that this would somehow improve sound quality; however, this has not been proved by measurements or properly conducted listening tests. From an electrical point of view, the two ways of making connections are, in principle, equivalent. This has led some to sarcastically refer to the practice as "buy-wiring", implying it is nothing more than a marketing gimmick for expensive speaker wire.