The invention relates in particular to a method of adjusting power spectral densities of a plurality of telecommunications lines sending data in a plurality of frequency sub-bands, a power spectral density being assigned to each sub band sending data. The method comprises the following steps: selecting at least one line, called the donor line, whose capacity for sending data is higher than a predetermined reference capacity, selecting at least one sub band of said donor line, and reducing the power spectral density assigned to the selected sub band to a predefined minimum power level in said sub band.