Text: Acoustic feedback occurs when sound vibrations from the loudspeaker travel back to the record player. The phono stylus then picks up the vibrations from the speaker along with the modulations in the record groove and feeds both signals to the amplifier and speaker. The result is - at best - a slight tonal blur or a rumbling noise. At worst, the re-amplified vibrations pile up, overload the amplifier, and produce a loud rumbling, humming sound that, if sustained, could damage the speakers.

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