As the source of a sound, emitted at constant frequency, moves towards a stationary observer, the perceived frequency increases due to the progressive compression of the wave-fronts, as described and easily observed by the well-known Doppler Effect. The reverse is also true, in which a receding sound source decreases in frequency relative to a stationary observer. This is happening all the time at some scale with loudspeaker diaphragms, which continuously move towards and away from a seated listener whilst trying to reproduce a wide range of frequencies simultaneously. This must introduce some inaccurate deviations compared to the original sound source and gives rise to intermodulation distortion, in which higher frequencies are modulated by lower frequencies to some extent. Theory dictates that the effect is accentuated in proportion to the operating bandwidth of the driver (so 5-way is better than 3-way is better than 2-way in this respect) and is akin to the effects of low level jitter being introduced.
I wonder, how great is the effect of Doppler distortion in reality, at its worst with sustained low frequency bass excursions modulating higher frequencies, and could, or should, Exakt attempt to compensate for such anomalies?
I wonder, how great is the effect of Doppler distortion in reality, at its worst with sustained low frequency bass excursions modulating higher frequencies, and could, or should, Exakt attempt to compensate for such anomalies?