All Pass Filter

All Pass Filters are so named because they do not affect the amplitude response of the signal passing through it.  Instead, they affect phase response only and, therefore, can be used to compensate for the phase anomalies caused by equalizers, crossovers and other filters.  All Pass Filters are available with up to sixteen bands.

 

 

Active Band selects the current band to be adjusted.

 

Center Freq (Hz) adjusts the center frequency for the current band.  

 

Bandwidth (oct) adjusts the range of frequencies, above and below the center frequency, which are affected by the current band.  These settings may also be adjusted by dragging the band controls shown inside the graph.  Dragging the larger center dot affects center frequency.  Dragging either of the smaller dots affects bandwidth.

 

Add Band and Remove Band work within the designated number of bands for the filter.  

 

Bypass Band and Bypass All disable the band(s) without changing settings.  

 

Drag Points turns on/off the band controls, revealing the resultant curve only.  

 

Band highlights the phase response of the current band inside the graph.

 

The Transfer Function object can be used in conjunction with All-Pass Filters to help visualize the effect of this block on the phase response of the signal.