Live Sound 101: Cables & Connectors for PA Systems Explained

When it comes to PA systems, sound is only as strong as the cables connecting it all together.

Why Cables Matter in Live Sound

• Reliability: A single bad cable can take down a show.
• Signal Quality: Balanced vs unbalanced connections determine how much noise gets into the system.
• Safety: Using the wrong cable (e.g., mic cable for a speaker) can fry gear.

Common Connectors in PA Systems

XLR Connectors

• Industry standard for microphones, mixers, and powered speakers.
• Sturdy, lockable, and built for professional use.
• Supports balanced transmission (cancels noise).

TRS & TS (Jacks)

• TRS (Tip-Ring-Sleeve): Used for balanced signals, headphones, and stereo connections.
• TS (Tip-Sleeve): Used for instruments like guitars and keyboards.
• Watch out: using the wrong one can create hum or dropouts.

Combo Jacks

• Found on many mixers and interfaces.
• Accepts both XLR and TRS — versatile for stage setups.

RCA (Phono Connectors)

• Common on consumer AV gear.
• Always unbalanced, prone to noise on long runs.
• Red = right, White = left.

USB Connectors

• Used on modern mixers for recording or playback from a computer.
• Great for streaming, recording live sets, or backing tracks.

Types of Cables

Mic Cables (Balanced)

• XLR male → XLR female.
• Cancels noise, ideal for microphones and long runs.

Line Cables (Unbalanced)

• TRS or TS phone jacks.
• Used for instruments and keyboards.

Speaker Cables (for Passive Speakers)

• Not shielded. Built to carry high-power signals.
• Often use SpeakON connectors (lockable, safe).

⚠️ Never substitute mic cables for speaker cables, it can damage your amp.

Snakes (Multicore Cables)

• Bundles multiple audio lines into one thick cable.
• Saves time on stage and keeps cables tidy.
• Standard for large bands, conferences, and corporate AV.

Balanced vs Unbalanced Signals

• Balanced: 3 wires (hot, cold, ground). Cancels out noise. Ideal for long cables.
• Unbalanced: 2 wires (hot, ground). Cheaper, but picks up noise on long runs.

👉 Rule of thumb: use balanced whenever possible, especially for microphones and long stage runs.

Pro Tips for Event Planners & Engineers

✅ Keep mic cables short for less noise.

✅ Use DI boxes to convert unbalanced to balanced.

✅ Label cables to save time in setup and troubleshooting.

✅ Always carry a few spares, cables fail more often than gear.

Key Takeaway

Cables may not be glamorous, but they’re the lifelines of live sound. Knowing the difference between XLR, TRS, RCA, and SpeakON  and when to use balanced vs unbalanced, separates smooth shows from disasters.

Shout Out to our contributors:

Johnny White

RSA🇿🇦 Live Sound Engineer