Dual-Mic Phase Alignment Planner

What this tool is for

Convert two source-to-capsule distances into arrival delay, sample offset, and phase at one frequency. Recording tools convert documented device specifications and measured waveform evidence into loading, level, headroom, and timing comparisons. They never authorize speaker-level connections or powered-device repair.

Use it when you can describe the current state and need a defensible next check. It is not a shortcut around inspection: preserve the starting state, change one variable, and verify the result under the same conditions.

Before you begin

Measure from one acoustic source datum to each capsule’s acoustic center. Record distance unit, air temperature, sample rate, and one frequency of interest; secure stands before moving microphones.

Use a stable, tuned instrument unless the page specifically investigates tuning.
Name the physical reference, unit, and test condition beside every important number.
Keep the original measurements so any reversible change can be returned to baseline.

Input guide

Distance unit: sets the interpretation and display unit; do not mix units elsewhere in the same run.
Microphone 1 distance: supplies a measured geometric quantity whose datum and resolution should be written down.
Microphone 2 distance: supplies a measured geometric quantity whose datum and resolution should be written down.
Air temperature (°C): provides a measured or counted input; confirm the allowed range and repeat the reading before relying on it.
Sample rate (Hz): provides a measured or counted input; confirm the allowed range and repeat the reading before relying on it.
Frequency to inspect (Hz): provides a measured or counted input; confirm the allowed range and repeat the reading before relying on it.

Input labels describe evidence, not targets. A placeholder demonstrates format only; it is never a recommendation for a particular guitar.

How the result should be read

Use the sample offset as an arrival-time comparison and confirm the waveform. Delay the nearer channel or move the farther microphone closer, then repeat the physical and recorded measurements.

Read priorities from top to bottom, but stop as soon as new evidence contradicts an earlier assumption. Save or print the result ticket with the entered conditions so another person can reproduce the decision.

Method and logic

The model estimates speed of sound as 331.3 + 0.606 × temperature °C, converts distance difference to arrival time and samples, and converts signed delay to phase at the entered frequency.

The page keeps calculation and diagnostic claims deliberately bounded. Display rounding improves readability, while the underlying logic uses entered values; descriptive branches report relative tendencies and the evidence needed to confirm them.

Worked example

At 20 °C, a 34.33 cm path difference is about 1.000 ms and 48 samples at 48 kHz. At 1 kHz it is approximately one 360-degree cycle, while other frequencies have different phase relationships.

The example demonstrates reasoning, not a universal setup specification. Substitute real measurements and repeat the final test before accepting the next action.

Assumptions and limitations

Room reflections, cabinet dimensions, off-axis paths, acoustic-center uncertainty, polarity, filters, loudspeaker radiation, and broadband comb filtering are not predicted by a one-path, one-frequency model.

Instrument design, service history, measurement error, and player technique can outweigh a calculator or checklist. Where manufacturer instructions exist for the exact hardware, use those instructions and record the revision consulted.

Safety and stop conditions

Turn monitoring and outputs down before changing connections. Never connect an amplifier speaker output to a DI, reamp box, pedal, microphone input, or audio interface unless the exact manufacturer documentation explicitly provides the compatible speaker-level load/input. Do not open an amplifier, power supply, or mains device. Stop for clipping, electrical sensation, heat, odor, damaged cables, unstable microphone stands, or a specification you cannot verify.

Related workflow

Round-Trip Alignment Calculator — Convert measured transient positions into round-trip delay and remaining sample compensation.
How to Measure a Guitar Recording & Reamp Chain — Capture comparable levels and transients without connecting a speaker output.
Pickup Phase Troubleshooter — Distinguish combined-position phase symptoms from pickup height, output, and wiring differences.

Open the related page that answers the next unresolved question; do not run every tool as if every system needs adjustment.