Butterworth filter
type of signal processing filter designed to have a frequency response as flat as possible in the passband
en-GB/bʌtəɹwɜːθ ˈfɪltə/
en-US/ˈbʌtɚˌwɝθ ˈfɪltɚ/
type of signal processing filter designed to have a frequency response as flat as possible in the passband