I've just begun building a bass (20-200Hz) class D amplifier and already ran into some problems.
The audio source is a car radio with 1V p-p signal. I firstly feed that sigal through a band-pass filter with corner frequencies at about 20Hz and 200Hz. This is how it looks like in LTspice:
Upper three op-amps are configured as high-pass and lower three as low pass active filters. The frequency response of the circuit looks good, but there is -100 to -1300° phase shift. I am wondering what is the importance of phase shift in such amplifiers? Can I just ignore it or should I compensate for it? How would I go about compensating the phase shift?
Note that I am building this for learning purposes and the output doesnt have to be/wont be really clean or anything like that. But I would like it to "sound" reasonably well, so will the phase shift cause distortions or anything like that?
9Hz to 500Hz area, their attenuation levels are ~30dB.
100Hz to 500Hz area zoomed into 0dB to -30dB attenuation level.
This is a picture of plotted group delay vs frequency.