The Complete Guide to Audio Cables and Connections

## Analog Audio Cables

Analog cables transmit a continuous electrical wave representing the audio signal. Quality can degrade with distance, interference, and poor shielding — but for short runs, any quality cable works fine.

### 3.5mm TRS / TRRS

The ubiquitous headphone connector. Found on phones, laptops, headphones, and audio interfaces.

- **TS** (Tip-Sleeve): Mono, unbalanced. Used for guitar cables.
- **TRS** (Tip-Ring-Sleeve): Stereo headphone or balanced mono. Studio monitors.
- **TRRS** (Tip-Ring-Ring-Sleeve): Headset with microphone. Smartphone headsets.

**Max recommended length**: 3m unbalanced; beyond that, use balanced XLR.

### 6.35mm (1/4 inch) TRS / TS

The professional version of 3.5mm — physically larger and more robust. Standard for:
- Guitar and bass instruments (TS, unbalanced)
- Studio monitor inputs (TRS, balanced)
- Mixing desk channels

### XLR (Balanced Audio)

Three-pin XLR connectors carry balanced audio — the gold standard for professional audio. Balanced cables cancel out electromagnetic interference by inverting the signal on one conductor and reinverting at the destination.

**Advantages**:
- Runs up to 100m+ without signal degradation
- Immune to hum from power cables and lighting
- Locking connector — won't pull out accidentally

**Use XLR for**: Microphones, stage systems, studio monitors, patch bays, broadcast

### RCA

Two-conductor phono connector (red/white for stereo, yellow for composite video). Found on hi-fi receivers, turntables, DVD players, and legacy AV equipment. Unbalanced, susceptible to hum on long runs.

## Digital Audio Cables

### TOSLINK (Optical)

Carries digital audio as light pulses. Common on TVs, soundbars, and AV receivers.

- **Max bandwidth**: 5.1 surround (Dolby Digital, DTS). **Cannot** carry Dolby Atmos or DTS:X.
- **Max length**: 10m (consumer); 30m with premium cable
- **No ground loops** — optical isolation prevents hum between components

### S/PDIF (Coaxial)

Same digital format as TOSLINK but over coaxial cable with RCA connectors. Slightly better bandwidth than TOSLINK in theory; in practice indistinguishable.

### HDMI ARC / eARC

HDMI's Audio Return Channel lets audio flow from TV to soundbar over the same cable used for video.

| Feature | ARC | eARC |
|---|---|---|
| Max audio | 5.1 Dolby Digital | Dolby Atmos (lossless) |
| Bandwidth | 1 Mbps | 37 Mbps |
| Cable | Standard HDMI | Ultra High Speed HDMI |

**eARC is the right choice** for modern soundbars and AV receivers — it's the only way to get lossless Dolby Atmos from a TV.

### AES/EBU

Professional digital audio standard using XLR connectors. Found in broadcast, recording studios, and high-end AV installations. Supports 24-bit/192kHz audio.

## Choosing the Right Connection

| Scenario | Best Connection |
|---|---|
| TV to soundbar | HDMI eARC |
| Microphone to interface | XLR |
| Guitar to amp | 6.35mm TS |
| Studio monitors | 6.35mm TRS or XLR |
| Headphones | 3.5mm TRS or 6.35mm TRS |
| Turntable to receiver | RCA |
| PC audio to powered speakers | 3.5mm TRS |
| Long-run stage cable | XLR |