A Filter is an electronic circuit designed to attenuate a specific range of frequencies while allowing others to pass through unaffected. It serves as the primary tool for subtractive synthesis and audio corrective work. The point at which the filter begins to operate is called the cutoff frequency. Beyond this point, the effectiveness of the attenuation is defined by the filter slope, which indicates how steeply the volume drops off as the frequency moves away from the cutoff. This slope is typically measured in 6dB increments per octave, corresponding to the number of poles in the circuit design. For instance, a 1-pole filter provides a gentle 6dB/octave slope, suitable for subtle tone shaping, whereas a 4-pole filter provides a steep 24dB/octave slope, ideal for creating deep bass sounds and sharp, synthetic textures.