Do Digital Equalizers Cause Phase Shifts? 2009-06-28 10:11:35 According to http://www.ethanwiner.com/EQPhase.html:QuoteTo create an equalizer from a digital delay line you tap into one of the intermediary memory addresses and feed a varying amount back to the input. Just like the feedback control on a tape recorder-based delay like an old EchoPlex. Except without all the wow and flutter. You can also reverse the polarity of the tapped signal before sending it back to the input to get either cut or boost. The bottom line is the delayed sound combines with the input - just like a flanger effect - to create peaks and dips in the frequency response. By controlling which addresses along the delay route you tap into, and how much of the tapped signal is fed back into the input and with which polarity, you create an equalizer. With an analog EQ the delays (phase shift) are created with capacitors and inductors. In a digital EQ the delays are created with a tapped shift register. But the key point is that all EQ shifts phase, unless it uses special trickery.All equalizers, regardless of their analog/digital domain, cause phase shift. So I ran a quick verification:I converted 16/44.1 RMAA reference wav with Foobar2k, EQ on, and analyzed the reference wav with RMAA.Phase did not change at all. Is my verification wrong? Do Digital Equalizers really shift phases?