Class D amplifiers have very little phase shift

There's no way I would put a 10uF cap in parallel with a speaker!! :)

Shown values don't make any sense.  10uF would represent about 0.8 ohm capacitive reactance at 20kHz, while series resonance of  1mH and 10uF would be at 1.5kHz

@kijanki 


The values were picked at random. They aren't real. :) As I wrote, the point was not the values, but where the parts were. :)

E

@erik_squires

Thank you. As for the phase shift, datasheet for the modules in my previous class D amp (Icepower 200ASC) show about 18-30deg phase shift at 20kHz dependent on the impedance of the speaker. Every amplifier has some phase shift at 20kHz because of the limited bandwidth. My amp had bandwidth limit of 65kHz/-3dB but many amplifiers with even lower bandwidth, hence larger phase shift, are praised for wonderful and extended highs. Lamm ML3 that has only about 40kHz/-3dB limit was praised by Stereophile as "airy and extended on top". Yes, I understand that phase shift can suppress highs by improper summing of harmonics, but dynamic speakers at these frequencies have usually inductive character, meaning that they accelerate phase (that would also negatively affect treble). Perhaps such phase shift is not that bad or effect of it is so negligible (who can hear 20kHz) that we don’t even hear it.

The first graph is the phase response of the impedance the second graph is of the frequency.