How many db/octave is each order of filter?

Each order of a filter typically represents a specific attenuation rate, measured in decibels (dB) per octave. When discussing filters, particularly in the context of audio production, it's essential to understand that the order of the filter directly correlates to how steeply the filter will attenuate (reduce the level of) the signal beyond its cutoff frequency.

A first-order filter, which is the most basic type, provides an attenuation of 6 dB per octave. This means that for each doubling of frequency above the cutoff point, the output signal level decreases by 6 dB. So, a first-order low-pass filter will reduce the signal’s strength at a rate that is fairly gentle compared to higher-order filters.

In contrast to 6 dB per octave, higher order filters, such as second-order and third-order filters, will have steeper roll-offs of 12 dB per octave and 18 dB per octave, respectively. This relationship continues with fourth-order filters at 24 dB per octave, meaning that each order of filter results in a doubling of the attenuation effect beyond the basic first-order.

Understanding the principle of dB per octave for filters is crucial in sound design and audio production, as it helps determine