As air warms up, its molecules move faster and sound travels faster. The frequency stays the same, so the wavelength gets longer.
Press a key to play the note and set the frequency. One octave up doubles the frequency and halves the wavelength.
Example: two loudspeakers play the same sound and speaker B is Δd farther from the listener. The sound covers this extra path in Δt = Δd / v.
At room temperature (20 °C) · speed of sound 343.4 m/s
At 180° the two waves cancel each other. This is what happens when one loudspeaker cable is wired the wrong way round (reversed polarity). The same happens when the path difference between two loudspeakers is half a wavelength.
At room temperature (20 °C) · speed of sound 343.4 m/s
The frequency is calculated from f = v / λ (within 20 Hz – 20 kHz).
Delay is how late a source plays its sound (like the delay on a mixing console). You can compensate a distance difference with delay and bring the two sounds back into phase at the listener.