Q: “I have a question about your Word for the Day ‘phase shifter.’ You say it is in the family of time-based effects, however, I recently read in another on-line article that it’s not considered a time-based effect. The article said it was an EQ effect. Just wondering why the discrepancy?”
A: The other article is wrong.
…okay, that’s a little strong. There is confusion about this, and it is understandable. First we have to settle on the semantics of what constitutes a time-based effect. My/our definition is that it’s any effect that uses the manipulation of time (i.e. delay) to achieve its results. Anything that messes with the relative phase of signals is, by definition, changing where it falls in time. If you take two identical signals, and then delay one of them by a microsecond, they are now partially out of phase with each other. Depending upon the signal’s content and the amount of delay applied, the effect is quite audible. This would seem to clearly point to a phase shifter being a time-based effect. Funny thing is, however, virtually every analog EQ circuit also has a time component to it. When EQ is applied to signals, some elements can become delayed very slightly (see WFTD Group Delay), effectively phase shifting them. Phase shifting is often achieved with EQ circuits. Nevertheless, the actual effect on the signal is the same: it, or certain frequency ranges of it, are delayed by small (and often varying) amounts. This has caused a lot of confusion about this process over the years.
Ultimately the argument is a purely semantic one. Regardless of how the effect happens to be created – whether you want to call the circuit an EQ circuit or a delay circuit – the effect is a time-based effect and should be treated as one. The net result on the signal, including where and how you’d apply it in your signal chain, has everything in common with other time-based effects (reverb, delay, flanger, chorus, etc.) and very little in common with things that aren’t considered time-based, such as compression, distortion, equalization, even though each of these potentially has a time or phase component to its process as well.