XLR to XLR Wiring: Building the Straight Cable and Knowing When to Reverse It
Quick answer / TL;DR: Short answer: the standard XLR to XLR wiring is straight – pin 1 (shield) to pin 1, pin 2 (hot) to pin 2, pin 3 (cold) to pin 3, at both ends. Build it by preparing the shield and conductors, terminating each to its same-numbered pin, securing the strain relief, and verifying continuity plus phase. A reversed pair (swapping 2 and 3 at one end) is a deliberate tool for correcting an external phase inversion – never the default, and always a decision, not an accident.
Wiring an XLR to XLR cable is usually the straight build – each pin to its same-numbered pin at the other end, phases aligned. But the wiring question that actually comes up is the reversal: when a straight build produces a thin, hollow channel, the fix is sometimes a deliberately reversed pair. Knowing the standard build cold is what makes the deliberate reversal a tool instead of a mystery.
This guide walks the straight XLR to XLR wiring end to end, explains the reversal case, and puts the phase check at the point where it belongs – the finish of the build.
The Straight Build, Step by Step
| Step | Action | Check |
|---|---|---|
| 1 | Cut and strip the cable to length | Clean jacket strip, conductors intact |
| 2 | Prepare the shield – gather the braid, do not fray it | Shield forms a single path to pin 1 |
| 3 | Prepare the conductors – twist strands tight or ferrule | No fanned strands |
| 4 | Terminate pin 1 to shield, pin 2 to hot, pin 3 to cold | Same-numbered pins at both ends |
| 5 | Secure the strain relief | The jacket, not the joint, takes the pull |
| 6 | Verify continuity on all three pins | No opens, no shorts |
| 7 | Verify phase – pin 2 hot, pin 3 cold aligned | The straight relationship holds end to end |
The Reversal Case: When 2 and 3 Swap
A straight build keeps the phase aligned between ends. If the system introduces a phase inversion elsewhere – a device with a polarity switch set the wrong way, a speaker wired reversed, a patch that crossed – the channel sounds thin and hollow. The deliberate fix is a reversed pair: swap the hot and cold at one end so the cable's inversion cancels the system's. The reversal is a correction applied with knowledge of where the inversion comes from – applying it without that knowledge just moves the problem.
| Situation | Correct wiring |
|---|---|
| Standard mic or line run | Straight – never reversed by default |
| System has a known external inversion | Reversed pair, to cancel it |
| Two sources summing out of phase | Correct one source's polarity, or reverse its cable deliberately |
The Phase Check: The Build's Finish
- A continuity check confirms each pin reaches its conductor – the cable is electrically complete
- A phase or polarity check confirms pin 2 is hot and pin 3 is cold, aligned for a straight build – the cable is electrically correct
- The two checks are different: continuity says the cable connects, phase says it connects correctly
- A cable that passes continuity but fails phase is the thin-sound cable – wired, but reversed
Common Wiring Errors in XLR to XLR Builds
| Error | Symptom | Fix |
|---|---|---|
| Shield frayed onto pin 2 | Dead or heavily degraded channel | Re-prepare the shield; keep it clear of the signal pins |
| Strands fanned at the joint | Intermittent contact, works until vibration | Re-terminate with a tight twist or ferrule |
| 2 and 3 swapped at one end | Thin, hollow sound (phase) | Re-terminate straight, or reverse deliberately if correcting a known inversion |
| Shield open | Hum and noise | Restore the shield to pin 1 at both ends |
Per-connector termination torque and strain-relief part specifications are not provided in the knowledge base. Follow the connector manufacturer's instructions for the specific XLR shell being wired, and keep the phase check as the build's final step.
Real-World Applications
The batch build
A venue wires a batch of fixed XLR to XLR cables; each passes continuity and phase before installation. The phase check is the batch's quality gate – a reversed cable is caught at the bench, not in the show.
The phase correction
A channel sums thin with its neighbor. The investigation finds a device polarity switch set reversed – correcting the switch is the clean fix; where the switch is unavailable, a deliberately reversed cable at that channel is the tool.
The field repair
A cable's connector fails in the field. The re-termination follows the straight build, and the phase check on the repaired cable is what confirms the repair restored the original relationship.
Related reading: The pin functions the build terminates to? Read the pinout guide — blogs/news/xlr-connector-pinout
Related reading: Browse XLR to XLR cables, straight wired — collections/audio-cables
Frequently Asked Questions
What is the standard XLR to XLR wiring?
Straight – pin 1 to 1, pin 2 to 2, pin 3 to 3, with pin 2 hot and pin 3 cold aligned at both ends. The reversal is a deliberate exception, not the standard.
How do I know if I need a reversed XLR cable?
You need one when a known external phase inversion makes a channel sound thin and hollow, and the inversion cannot be corrected at the device. Without that known cause, build straight – a random reversal just creates the problem it pretends to fix.
Is the phase check necessary if the cable 'works'?
Yes – a reversed cable works, carrying a thin, hollow signal that is misdiagnosed as a gear or mic problem. The phase check is the only step that distinguishes a working cable from a correctly wired one.
Can a reversed cable damage equipment?
No – a 2/3 reversal inverts phase, it does not damage gear. The consequence is tonal (thin, hollow, out-of-phase summing), which is correctable. Damage risks come from other errors, like a shield shorted to a signal pin.
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