Audio Cables and Connectors Common Audio Cables Balanced: Have two conductors and a shield or ground. Used for low impedance - balanced circuits (+4 dBu) Unbalanced: Have one conductor and a shield. Used for high impedance unbalanced, or -10 dBV signals Speaker wire: 2 conductors and no shield A Balanced Line An Unbalanced Line Speaker Wire 3 Electrical Characteristics of Wire Resistance/ Impedance: Will decrease the audio signal level Capacitance: Will roll off high frequencies Inductance: Will alter the frequencies of the signal in various ways Specs for quality wire Resistance/ Impedance: Less than 100 ohms per 1000 feet Capacitance: Under 100 Pico farads per foot Inductance: Depends on how the wire lays - coiled wire has more inductance than uncoiled wire Wire Gauge The diameter of wire is measured in gauges The smaller the gauge - the bigger the diameter Audio cables are typically 20 - 22 gauge Speaker cables can be from 18 and down depending on the system Comparison of Balanced/ Unbalanced Lines Balanced Unbalanced Fairly insensitive to electrostatic noise/ RF interference Very sensitive to electrostatic noise Can be used in lengths from 25 - 300 feet At lengths greater than 25’, much of the high frequencies in the signal start to disappear XLR, TRS Connectors TS, RCA Connectors Used for low mics, pro line level gear Used for high mics, line level instruments, consumer or semi-pro gear Guidelines for Speaker Cable If you are driving an audio system outputting under 500 watts RMS, and your speaker wire runs are under 100 feet, use 18 gauge speaker cable・ If you are under 500 watts RMS and greater than 100 feet, but under 250 feet of wire, use 16 gauge speaker cable・ If you are between 500 and 2000 watts RMS and under 100 feet of speaker wire runs, use 16 gauge speaker cable・ If you are between 500 and 2000 watts RMS and and greater than 100 feet, but under 250 feet of speaker wire runs, use 14 gauge speaker cable・ If in excess of 2000 watts, you should refer to the documentation associated with your PA system power amplifiers and use what they recommend. Balanced (TRS) 1/4” Connectors T = Tip R = Ring S = Sleeve Balanced XLR (Mic) Connectors Male XLR Female XLR Unbalanced (TS)1/4” Connectors Sometimes called an instrument or guitar cable Unbalanced RCA Connectors Common Speaker Connector found in Studios Balanced Multi-pin Cable •Used to connect 2 or more channels of audio on a single connector. •Commonly found on recording console I/O,DAW interface I/O, audio patchbays, as well as multi track tape machines. •Used in conjunction with multi channel audio connectors. Balanced Multi-pin Connectors ELCO Balanced Multi-pin Connectors D-SUB Balanced Multi-pin Connectors DL Audio Patchbays Most pro audio studios use TT (tiny telephone) patchbays. Each patch point is electrically balanced. Front panel switches make it easy to change between full, half and non-normalled connections. Punch style patchbay by ADC Patchbay with soldered connections