What is Phase Angle and Shifting?

Mrtennis: Not familiar how ESL's compare with their integral transformer but magnetic planars have no voice coils and primarily resistive across their range and have negligible phase "distortion". That, in itself, doesn't make them ideal but I've wondered if that has always been part of the appeal.

Ok thanks. I get the picture. The topic is a can of worms. Let me try to simplify the question a little. In the context of tube versus SS amps, I recall reading comments that certain speakers can be hard to drive for certain amps because impedance in the lower bass frequencies is very low AND the speakers present "hard" phase angles. Anyone care to explain the concept??

Also, as a high level observation, there are a number of OPs that ruminate about accuracy and precision of sound systems. In light of the thoughtful comments made here and elsewhere about so called time and phase coherent speakers, it would appear the macro concept of accuracy and precision is disingenuous. Even if one believes that their electronic gear perfectly amplifies input signal information, i.e., so called gain on a wire, the speakers are at best the culmination of design compromises that include issues pertaining to time and phase conherence.

Notably, there are several comments in various OPs that contend that not all time and phase differences sound that bad. And further, attempts to "correct" such differences create other sonic problems.

In short, if one would compare the complex sound waves comprising music produced by a speaker to the same electronic analogue signal fed into the speaker, there must be considerable distoration, especially around the cross over points of the drivers as well as at the resonant frequencies of the drivers. However, I surmise that the difference between a speaker that sounds good and one that does not is a function in large part of whether the harmonic distortion sounds good or bad.

It's kinda' like tryin' to squeeze jello in the palm of your hand. When you tighten your hand around the jello, some is bound to squeeze out between your fingers. There's no getting around it. So the trick is squeeze, but not too much.

Thanks for the information. This discussion puts a different spin on speakers, at least for me.

"However, I surmise that the difference between a speaker that sounds good and one that does not is a function in large part of whether the harmonic distortion sounds good or bad."

Or an amp, or a concert hall, etc. We all like distortion :).

Mrtennis: Forgot to mention that dipoles have rear dispersion that's out of phase and can react with the room in many ways. For myself, it's most noticeable on vocals.

re: Bifwynne's question:

Without an entire dissertation, consider the analogy of a hose through which water is passing at the end of which is a nozzle. Difficult impedances involve a negative, or capacitive phase angle. That means that the current demand, or flow rate of water, increases before the voltage, or water pressure, is produced that is sufficient to drive the current/water through the load (spkr)/nozzle.

One critical aspect of an amplifier's specification is its ability to deliver sufficient current to capacitivie impedances which most commonly occur at low frequencies.