20 db/decade 6 db/octave意思
The terms "20 dB/decade" and "6 dB/octave" are used in the context of filter slopes or roll-off rates in signal processing and electronics. They describe the rate at which the amplitude of a signal decreases with respect to frequency.
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20 dB/decade: This term is used to describe the roll-off rate of a filter in the frequency domain. A "decade" refers to a tenfold change in frequency. So, 20 dB/decade means that the amplitude of the signal decreases by 20 dB for every tenfold increase in frequency. This is equivalent to a -2 dB/octave slope, because an octave is a twofold increase in frequency, and -2 dB/octave × 5 = -10 dB/decade.
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6 dB/octave: This term also describes the roll-off rate of a filter, but it is used in the context of musical pitch or frequency doubling. An "octave" refers to a doubling of frequency. So, 6 dB/octave means that the amplitude of the signal decreases by 6 dB for every doubling of the frequency. This is a steeper slope than the -2 dB/octave mentioned above.
In summary, 20 dB/decade and 6 dB/octave are both measures of how quickly the amplitude of a signal decreases with increasing frequency, but they are used in different contexts and can be converted into equivalent values for comparison.