What is the difference between a balanced and unbalanced cables?
All audio cables are shielded from electromagnetic interference, the difference is in how many conductors are inside. This shielding is imperfect for getting rid of noise, so balancing was invented. On an unbalanced cable there is a single conductor that carries the signal which is wrapped by the shield which is grounded. On a balanced cable there are two conductors, often called High and Low, Hot and Cold, or Pin 2 and Pin 3 (pin 1 is the ground). The shield is grounded, but not is part of the signal path like on an unbalanced cable. These two conductors carry the exact same signal but are polarity inverted from each other. When a balanced input gets these two signals, it re-inverts that out of phase signal to restore the original signal, thus taking any noise generated along the way OUT of phase. (Common Mode Rejection is the specification of how well circuitry rejects interference that is common to both the High and Low conductors.) A 1/4″ balanced cable is called a TRS or Tip-Ring-
