phase shift after low pass filter

[erez1012]

hi all
i buy LPF kit for my open baffle speaker.
i have FR speaker connected to class A direct with not filters, the FR start at~300Hz.

now for the bass: i change the filter to work at 10-250Hz with nice FR, but the phase shift at this rage (about 100Hz) us 180 deg !!!

how much is important, i know about amplitude canceling, but here the FR not working in thus frequency's.

do i need to change my filter?

thanks

 

[picowallspeaker]

If it's 180° it's ok, just invert connection at the loudspeaker !

 

[erez1012]

sorry for no plot the phase shift.

until 100Hz its 180 deg, after that its start to return to 0.

the question is if this influence the sound, because the FA speaker is not "work" in thus range.


the next pic is new dasign that i made just now, what do you think?

 

[Nrik]

Phase shift is an unavoidable and normal function of filtering.
All crossovers has phase-shift, even if some claim that they are "phase-correct".
So don't worry about it.

If you want to know it all, then read more from the master himself Siegfried Linkwitz.
Click on his small links to his hand-drawn simulations...they explain more than a 1000 words.

 

[erez1012]

yes i read about "Siegfried Linkwitz." WOW

what do you think about the design in the picture? it is ok? there is something i miss?
thank

 

[picowallspeaker]

The correct phase alignment should be done at crossover frequency; the woofers alters its phase response at resonant frequency ( it's due to the impedance "bell" that has capacitative reactance type before the peak and inductive reactance after ).
If the phase is sufficiently spaced along the spectrum ( more than an octave) it would be less audible...