XLR - The Balanced Audio Standard
3-pin locking connector - signal+, signal-, ground. The pro audio default for microphones, line signals and PA up to 100 m without hum.
The XLR connector (Cannon X-Latch-Rubber) is the workhorse of professional audio. Three pins - Pin 1 = ground / shield, Pin 2 = signal+ (hot), Pin 3 = signal- (cold) - carry the signal twice in opposite phase. The receiver subtracts the two and any noise picked up on the cable cancels out (common-mode rejection). Result: clean signal even on 100 m runs in noisy stage / venue environments. The latching mechanism prevents accidental disconnection during shows. P48 phantom power (+48 V on pins 2 + 3 against pin 1) feeds condenser microphones over the same three wires.
Technical Specifications
| Standard | IEC 61076-2-103 |
| Pins | 3 (Pin 1 GND, Pin 2 hot, Pin 3 cold) |
| Topology | Balanced / differential |
| Phantom power | +48 V (P48) - microphones |
| Latching | Yes - push-button release |
| Cable length | up to 100 m |
| Common-mode rejection | > 60 dB at 1 kHz |
Matching products in the shop
- XLR microphone cables
- XLR-to-jack adapters
- DI boxes
Frequently Asked Questions
Why send the signal twice in opposite phase?
Any noise (hum, RFI) picked up between transmitter and receiver appears on BOTH lines equally. The balanced receiver subtracts the two signals - noise cancels, original signal is recovered. This common-mode rejection is what enables 100 m clean cable runs.
Is phantom power dangerous to dynamic microphones?
Modern dynamic mics with proper transformer wiring are safe with P48 enabled. Ribbon microphones can be damaged - always check the spec sheet and use a dedicated dynamic input or an isolating cable if in doubt.
XLR vs TRS jack - both balanced?
Both can be balanced. XLR adds a locking latch and pin 1 grounding for shield, making it more robust over long distances. TRS jack saves space on rack equipment.
Related connectors in the glossary
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