Also called filament-hum or buzz, is a phenomenon of the clipped waveform of all phase-control dimmers. Higher wattage lamps are usually more susceptible, as are PAR56 and 64 lamps of all wattages.
The latest sine-wave dimmers, which work by altering the amplitude of the sine-wave rather than clipping it, eliminate this problem. Some concert halls, where ALL environmental noise is a distraction, are installing sine-wave dimmer today, with variable results.
It has been suggested that Sine Wave Dimmers are "the party the dimmer manufacturers gave, but nobody came", in the USA. Due to cost, and sometimes lack of reliability and poor design in early implementations (even by a well-known manufacturer), market uptake of Sine Wave dimmers in the USA has been minimal.
The latest sine-wave dimmers, which work by altering the amplitude of the sine-wave rather than clipping it, eliminate this problem. Some concert halls, where ALL environmental noise is a distraction, are installing sine-wave dimmer today, with variable results.
It has been suggested that Sine Wave Dimmers are "the party the dimmer manufacturers gave, but nobody came", in the USA. Due to cost, and sometimes lack of reliability and poor design in early implementations (even by a well-known manufacturer), market uptake of Sine Wave dimmers in the USA has been minimal.