Audio 40 - Q. Is the QED Audio 40 cable directional?
No, the Audio 40 range are not directional. This is because the cable is wired in traditional unbalanced mode, similarly to a co-axial cable, using the braid as both a shield and a path for return currents. This gives the cable exceptionally low capacitance and a high resilience against external high current noise sources such as nearby mains cables etc., as well as good immunity to external high voltage spikes such as light switches. In order to ensure that the left and right cables present an identical pathway to the music, they should be installed so that the writing on the cable faces the same way on both cables – it doesn’t matter which way the writing goes but if it reads from source to sink it will ensure that the direction of pull of the copper conductors is in the same direction as the notional direction of the musical signal.
On the other hand, when an older type QED interconnect has arrows printed on it, it is because it is wired in quasi-balanced mode where the shield braid is connected at the source end only (hence the arrows, so you connect it the right way round). This gives the cable an exceptionally high resilience against external high voltage spikes such as light switches as well as good immunity to external high current noise sources such as nearby mains cables etc.. if you connect the cables the wrong way round, the noise immunity will be affected and the sound is consequently degraded. The only downside to this is the capacitance is much higher, which we feel affects the sound stage and timing of the cable so we have moved away from this type of geometry in recent years.