phase correction filter

[emosms]

Hi,
Has anyone played with all pass phase correction filter?

Let's take two way active system.

If we put that filter on the tweeter chanel? Any benefits?
F.ex. - tone, stereoimaging?

I know that if the drivers themeselves are not phase/freq linear (impossible), if the cabinet design does not take physical placement into account - it won't help for phase linearity for the whole frequency band.
The best way is DSP and FIR filters.

So, does it worth the effort?

Regards

 

[Fast Eddie D]

I will tell you this. A properly designed passive crossover often includes a "Zobel" on the woofer (sometimes the other drivers too) that corrects impedance rise with frequency and also can correct the phase shift between the drivers. This can be a big step towards hitting the "sweet spot" at the crossover. Impedance and phase graphs are available for many drivers.

I tell you this because there's a thread about Zobel networks in the speaker forum that might give you some insight. So the answer to answer your question is yes you can and it's certainly worth a try. This could almost certainly be done with analog filters too. My personal experience is that some pretty simple active filters can go a long way towards correcting speaker response. I've had great luck with my analog line level filters so I would encourage you to see what the DSP can do. Please share your results.

 

[emosms]

Rod Eliot is not that much enthusiastic, neither rejects the idea..
- http://sound.whsites.net/pcmm.htm

Btw, anyone knows how to set the all pass filter in APO equalizer, so that one can control the phase shift?
- https://sourceforge.net/p/equalizerapo/wiki/Configuration reference/#filter

Using IIR?
- https://sourceforge.net/p/equalizer...ter-with-custom-coefficients-since-version-09

Many things to do on the list. Want to test it somehow or get feedback, before going to build it (alongside with many other pending stuff).

btw, if there is more than one cycle shift, one can use APO delay:
- https://sourceforge.net/p/equalizerapo/wiki/Configuration reference/#delay-since-version-09
I haven't tried to set a combined filter, so that delay is applied to part of the frequency spectrum... One can adjust f.ex. the group delay of a bass reflex cabinet 🙂

If all that stuff works with apo and there is noticeable difference, it would render useless the idea to build analog crossover 🙁.