Calculator features
Exact physical calculation with temperature adjustment for the speed of sound
Result in milliseconds and samples for DAW compensation
Canvas visualiser of comb filtering across the full audible spectrum
Microphone presets (XY coincident, snare, ambient)
Phase inversion simulation and relative gain control
Support for metric and imperial units
# What is phase cancellation and why does it ruin your mixes?
In the world of audio engineering, phase is one of the most critical concepts and, paradoxically, one of the most overlooked by beginners. When you record a sound source - such as a drum kit or guitar amplifier - with two or more microphones placed at different distances, the sound waves do not reach the capsules at the same time. This time difference, however small, causes a phenomenon known as phase shift.# The Comb Filtering phenomenon
When two identical signals are combined with a slight delay between them, a series of notches and peaks appear in the frequency response. Viewed on a spectrum analyser, the pattern resembles the teeth of a comb - hence the name. This effect destructively alters the natural timbre of the instrument.Impact on Low End
Phase cancellation is most devastating in the low frequencies, where the body of the sound disappears entirely.
Metallic Texture
Comb filtering adds an artificial coloration that sounds 'hollow' or overly processed.
# The influence of temperature on the calculation
Many sound engineers forget that air is a physical medium and its density changes with temperature. The speed of sound is not an immutable constant - at 20°C it travels at approximately 343 metres per second.v = 331.3 + (0.606 × T)
Surgical Compensation
A few degrees of difference can shift the cancellation points by several hertz. Using our calculator with the actual temperature of your studio guarantees perfect alignment in the DAW.# Critical recording scenarios
- Snare drum (Top & Bottom): Align both heads temporally to maximise punch.
- Overheads and close mics: Delay the close mics to match the phase of the overhead mics.
- Guitars with multiple mics: Blend a dynamic and a ribbon without losing low-mids.
- Bass DI and mic: Sync the direct signal with the amp mic for a massive sound.
# Physical Alignment vs. Digital Processing
Although our tool gives you the values to correct phase in your DAW after recording, we always recommend attempting the best possible physical alignment in the studio. Moving a microphone a few millimetres can be more effective than any digital processing. 343.2 m/s Speed @ 20°C
0.029 ms Milliseconds/cm
1.4 per cm Samples @ 48kHz
# Reference table: Distance vs. First Null
| Difference (cm) | Delay (ms) | 1st Null (Hz) | Affects... |
|---|---|---|---|
| 1 cm | 0.029 | 17160 | Extreme high end |
| 5 cm | 0.146 | 3432 | Upper mids (Presence) |
| 10 cm | 0.291 | 1716 | Mids (Presence) |
| 30 cm | 0.874 | 572 | Low-mids (Body) |
| 1 metre | 2.914 | 172 | Low end (Fundamental) |
# Pros and cons of correction methods
Voordelen
- Physical alignment: Less degradation of the original signal.
- Digital correction: Absolute precision at the sample level.
- Polarity inversion: Instant fix for 180° cancellations.
- Time compensation: Recovers lost impact and punch.
Nadelen
- Physical alignment: Difficult to adjust with microscopic accuracy.
- Digital correction: Can create pre-echo if applied incorrectly.
- Polarity inversion: Does not fix intermediate phase shifts.
- Time compensation: Requires precise measurement of each mic.