The TRS cable is an audio cable used extensively in the recording studios. TRS cables have multitude of functions for use in headphones, microphones, telephones, digital cameras, computers, amplifiers, electric instruments, and other audio equipment. TRS cables which stands for, ‘Tip’, ‘Ring’, ‘Sleeve’, can provide a high quality transfer of audio through its balancing capabilities.
Using TRS Cables in the Studio
Historically, TRS cables were first used as telephone switchboard connections. In fact, the quarter inch (1/4” or 6.35 mm) cable is one of the oldest electrical cables still in use today. Other historical uses of the TRS plug were for transistor radios as well as in earpieces of aircraft radios, though these plugs had a slightly smaller size (TT/Tiny Telephone)
TRS plugs commonly appear in three sizes: 3/32” or 2.5 mm (used primarily for cell phones), 1/8” or 3.5 mm (often used in headphones for portable music devices), and 1/4” or 6.35 mm. The later is most often the TRS cable size used in audio recording and amplification applications.
It’s important to understand the difference between cables that are balanced and those that are unbalanced. Unbalanced cables contain only two signals: a “hot” line carrying the signal and a “ground” (sometimes called “earth”) line, which acts as the return path for the electric signal. In a connector, the tip carries the hot line, while the sleeve will carry the ground signal. A balanced cable, however, contains an extra line which is called a “cold” line, in addition to the hot and ground lines. The cold line is an inversion of the hot line, which, when reversed and merged with the hot line, forms a stronger signal than than an unbalanced signal. For this reason and the capability of balanced signals to cancel external noise especially over long cable runs it’s recommended to balanced cables whenever available. The longer the cable, the more the risk of interference, which is why short cables runs (12 feet or less) can usually afford to be unbalanced.
TRS cables have the capacity to be used for a stereo signal. This is often found in headphone cables, where the tip sends the left channel signal and the ring the sends the right (with the sleeve still carrying the ground). However, most TRS cables in the audio studio are used to deliver balanced signals, giving a high quality signal transfer.
