Rumble (noise)

[1] In the context of audio reproduction rumble refers to a low frequency sound from the bearings inside a turntable.

The ‘unweighted’ response curve is intended for use in assessing the level of inaudible rumble with such intermodulation in mind.

An important factor affecting rumble is low-frequency resonance resulting from pickup arm mass bouncing against stylus compliance.

Most so-called rumble filters work by simply rolling off the low-frequency response, which is detrimental to sound quality.

Though several standards exist that define how rumble should be measured, they all have a common basis, and use the weighting curves shown here.