An all-pass filter alters phase and timing but not amplitude
Evidence
There is a special type of filter known as the “all-pass filter.” This is not a piece of wire! It is a filter that changes the phase of the signal’s frequency components without affecting their amplitude. Because the phases have been changed there is also an associated time response. — David Howard, Jamie Angus, coustics and Psychoacoustics, 481
There is a special type of filter known as the “all-pass filter.” This is not a piece of wire! It is a filter that changes the phase of the signal’s frequency components without affecting their amplitude. Because the phases have been changed, there is also an associated time response. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 483
Categorization
- DEFINE: Defines the all-pass filter by contrasting it with ordinary wire and its phase-only effect.
- corroborated: 6 independent passages support this claim — David Howard, Jamie Angus, coustics and Psychoacoustics, 481; David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 483
- XREF: connects to: Phase differences among wavelets reduce the total difference-tone amplitude; Every stage of the audio chain high-pass filters bass, accumulating phase shift.; Frequency, phase, and impulse responses are interchangeable transforms of each other (+4 more)