Filter

An electronic circuit designed to attenuate a specific range of frequencies. (See low-pass, high-pass and band-pass.) The amount of attenuation depends on the filter slope which is typically either 6, 12, 18 or 24dB/Octave. For example if a high-pass filter had a corner frequency of 100Hz and a 12dB/octave slope, a signal at 50Hz would be attenuated by about 12dB, and a signal at 25Hz by 24dB.