Pole

This is a technical term that helps describe the design of a filter. Each pole of a filter attenuates frequencies beyond its cutoff or corner frequency by 6 decibels (dB)/octave; the more poles, the stronger the filtering effect. A 4-pole low pass filter, for example, attenuates frequencies one octave above its cutoff frequency by 24 dB; frequencies two octaves above the cutoff are attenuated by 48 dB and so forth.