Studio Monitor Time Alignment Calculator — Distance, Delay & Phase
Monitor paths and audio settings
Often the crossover or another problem frequency.
Your measurements stay in this browser. No distances or settings are uploaded or stored.
Alignment result
Uncorrected path phase
25.17°Monitor B arrives 0.874 ms later than Monitor A, equivalent to 25.17° at 80 Hz.
| Monitor A acoustic travel time | 3.496 ms |
|---|---|
| Monitor B acoustic travel time | 4.370 ms |
| Speed of sound | 343.23 m/s |
| Wavelength at selected frequency | 4.290 m |
| Full-cycle offset | 0.0699 cycles |
| Nearest whole-sample residual | 0.001 ms (0.03°) |
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How to measure and time-align studio monitors
- Fix the listening position. Mark the point where your head or measurement microphone will be. Both distances must end at exactly the same point.
- Measure from comparable acoustic points. Use the manufacturer’s acoustic reference point when available. For the same monitor model, use the same physical point on each cabinet.
- Enter the two direct-path distances. The calculator identifies the nearer monitor and tells you how much electronic delay to add to it.
- Set the sample rate and check frequency. The sample conversion follows the session or DSP sample rate. Use the crossover frequency when checking a monitor/subwoofer handoff.
- Apply the delay, then measure. Use a dual-channel acoustic measurement or impulse response to account for driver, converter, DSP, and filter latency that a tape measure cannot reveal.
For left/right nearfields, physical symmetry is usually preferable to large electronic correction. For a subwoofer or displaced speaker, delay is commonly part of the alignment workflow.
Distance, time-delay, sample, and phase formulas
The geometric path difference is the absolute difference between the two measured distances:
Δd = |dA − dB|
That distance becomes arrival-time difference, samples, and phase with:
delay (s) = Δd ÷ c
samples = delay (s) × sample rate
phase (°) = frequency (Hz) × delay (s) × 360
The visible phase value is wrapped with phase mod 360°, but the full number of cycles remains in the detailed result. Wavelength is λ = c ÷ f.
The calculator estimates dry-air sound speed from absolute temperature using c = √(γRT), with γ = 1.4 and R = 287.05 J/(kg·K). This is approximately 343.2 m/s at 20 °C. Humidity, pressure variation, and air movement are not modelled.
Technical references: Yamaha Pro Audio — delay time and distance, Analog Devices — time delay to phase conversion, and NIST — speed of sound as a thermodynamic property.
How to interpret monitor delay and phase
If Monitor A is 0.30 m nearer than Monitor B, sound from A has less air to cross. At 20 °C the arrival difference is about 0.874 ms, so adding 0.874 ms to Monitor A makes the two ideal direct paths arrive together. At 48 kHz that setting equals about 41.95 samples.
Phase depends on frequency even when the time difference is fixed. The same 0.874 ms offset is about 25.2° at 80 Hz, 50.3° at 160 Hz, and one complete 360° cycle near 1.144 kHz. A wrapped result of 0° can therefore mean either zero delay or one or more whole cycles; consult the full-cycle value and delay result instead of judging alignment from wrapped phase alone.
Whole-sample rounding is not always necessary. Modern speaker processors and DAWs may offer delay in milliseconds, distance, or fractional samples. If only whole samples are available, the calculator shows the nearest integer and its residual error at the selected frequency.
Geometric time alignment does not flatten room response or guarantee summation. A crossover introduces frequency-dependent magnitude and phase, loudspeaker drivers may have different acoustic centres, and a subwoofer can add DSP latency. Measure both sources separately and together, check polarity, and confirm the impulse response and crossover summation after applying the calculated starting value.
Engineering estimate and limits
This calculator models direct propagation through still, dry air and assumes both measurements refer to comparable acoustic points. It does not measure electro-acoustic latency, crossover group delay, driver phase, reflections, or room modes. Do not treat the result as a substitute for calibrated acoustic measurement, manufacturer guidance, or listening verification.
Studio monitor time alignment FAQ
Which monitor should I delay?
Delay the nearer monitor—the one with the shorter acoustic path. The farther monitor is already delayed by the extra travel through air.
How does distance become milliseconds?
Divide the distance difference by the speed of sound, then multiply seconds by 1,000. At 20 °C, each metre of extra path is about 2.91 ms and each foot is about 0.889 ms.
How is phase calculated?
Multiply frequency by delay in seconds and by 360. Because phase repeats every cycle, the headline result is wrapped to 0–360°, while the detailed result shows the complete cycle offset.
Should I round to a whole sample?
Only if the processor requires it. Use the exact millisecond or fractional-sample value when supported; otherwise use the nearest whole sample and review the displayed residual.
Does equal distance guarantee the monitors are aligned?
No. It removes the ideal geometric timing difference only. Filters, drivers, converters, speaker DSP, polarity, and reflections can still change measured phase and arrival.
Does this page upload my measurements?
No. Calculation, copying, and CSV creation happen locally in your browser.