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1. PhaC can work
2. The frequency you put in shouldn't be an arbitrary frequency, but the crossover frequency from the drivers you want to align, f.e. when aligning midrange to midwoofers you choose f.e. 300Hz., for tweeter to midrange you type in 3000Hz (when crossing at 300Hz and 3000Hz).
3. PhaC only calculates phase based on driver specific filters.
3a. If you use the group eq to be able to use 30 bands of EQ for each driver PhaC will not work as it doesn't use the group eqs for calculations!
4. when doing it the "Mosconi way" you have to basically set T/A right at the very beginning (with safety crossovers for midranges/tweeters) with a binaural mic, otherwise results of PhaC may not be that good. I verified that with Frank Miketta.

Reason for 4 is the following:
Frank Miketta rightfully says if you set T/A it's a constant as it accounts for distances and speed of sound for both passband and stopband before you set the crossovers, i.e. the whole range of frequencies of the drivers. Crossovers and driver specific filters alter phase then in the crossover region, but passband phase stays the same, so you only have to adjust phase in the crossover region to get good alignment. All the builtin calculations are programmed for use of a binaural mic basically.

5. you really need to measure and verify it, 'cause sometimes it doesn't really work acoustically (ask me how i know!).
 

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2 things..

1) you are adjusting phase based off of the electrical signal. To be honestly, I really didn't read through all of this, but based on what it seems like you are doing, you may be correcting something that is just not there.
And this is one of the reasons why PhaC doesn't always work. In theory it should, but sometimes it just doesn't.
 

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I respect everything u wrote and I know that already, but I found this is the best method.
I know the mosconi way, tried is several time,
and I know that they say t/a first but I found that after applying the Phac the center of the stage shifts so you need to t/a again.
and I know it meant for the crossover points but you can utilize it the align the phase as you wish and this works perfect, I don’t tend to follow the line, but try things for myself.

and for me and all myfriend the Phac works.
If you don’t know how to t/a or basic steps of tuning it won’t help you. But it give you some extra if you do.

5. When I will found free time I will try to measure it you are right, but I can ear it for sure.
I tried it myself with the PICO 8/10 in my Mustang and afterwards i told Frank Miketta it didn't work as expected (at least for competitors).
Stage was good, no doubt, but stage was above the steering wheel when done as intended and this doesn't work out for a competition where the stage is expected to be in the middle of the dash (slightly left to the windscreen from a left hand drivers point of view). So i went back to my way of doing T/A with impulse responses and phase alignment via impulse measurements and stuff.

But i agree that this is a fast way to align phase, especially if you have a system like OpenSoundmeter or Smaart running on another screen to watch the changes in real time unlike like setting allpass filters by hand.
 

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If your using smaart it’s far more accurate and you don’t need to calculate everything in your head, just adjust it live and place crossovers very accurately, the above that I mentioned are not an issue when using smaart
Jl tun allows you to do a similar thing and model all pass filters based on crossovers, and again in reality it doesn’t change the fact that it’s not reflected in the real world due to phase not being perfectly flat from a driver or combination of drivers
If using Smaart PhaC allows you to change phase just with a slider and in real time as the calculated allpass filters are applied in real time to the system.
When watching it in real time in Smaart this is a real good way to set the phase as desired in a very quick way. Way quicker than typing in different allpass filters with bandwiths and stuff like that.
So PhaC can work if you use it a bit outside of the workflow as intended by Frank Miketta. ;)
 

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7. The order of phase degree is L + R separate and,
the woofer are our reference.
we start with mids-> woofers
tweeters -> mids
sub -> woofers
we chose "Phase Shifter"
If the phase on any driver is less than the driver you want to alter it to it wont work.
In your example if subs phase is -59° and woofers phase is -49° in phase you cannot use PhaC to adjust the sub to the woofer, but only the other way around, i.e. woofer to sub.
 

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phac can’t adjust anything automatically for the environment, so your left adjusting manually regardless
Same with Helix.
Look... i don't use PhaC myself most of the times. But all PhaC does in the end is set a 1st or 2nd order allpass filter with a frequency and in case of 2nd order a bandwith just like the variable phase slider in the Helix software does.
With Helix you move the slider and it automatically calculates the resulting allpass filter, frequency and bandwith, PhaC does the same, you move a slider and it automatically calculates the resulting allpass filter, frequency and bandwith for a frequency that you define. Only difference is, that Helix does this in 5.something degree steps and PhaC in 1 degree steps.
I already agreed with you that you should do that with some other software like Smaart or similar tools to minimize the amount of time needed, because you can see the result in the measurement software.
cathul said:
When watching it in real time in Smaart this is a real good way to set the phase as desired in a very quick way. Way quicker than typing in different allpass filters with bandwiths and stuff like that.
So PhaC can work if you use it a bit outside of the workflow as intended by Frank Miketta.
So i don't get it why you're arguing with me now.
 

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Well, PhaC is taking into account all the phase shifts from crossovers and driver filters, which the phase slider in Helix doesn’t. In this way PhaC might be more accurate after all. And as the OP outlined you need to transfer everything from the Mosconi to the Helix (or vice versa) to get accurate results, didn’t he?
 

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APFs have uses , but not like that. The problem is it can make the passband have a good phase, but the stop band is a catastrophe.
and that’s the part I think the engineers break down and don’t realize that almost everything that we hear is a mix of all the speakers playing.

so when you have detrimental timing discrepancies in the interaction areas there’s no way to come back from that…

And then you hear these catchphrases like, all past filters fix crossover phase twist. Which is actually the exact opposite of what they do, they add more phase twist. They simply move in the wrong direction.

All passes are a good tool to have, just not for this…
If you talk to Frank Miketta about the theory it totally makes sense to use a tool like PhaC or the Helix phase control for exactly this purpose.
From the workflow point of view with PhaC you are correcting phase differences that are caused by crossovers through the different slopes, especially with odd order crossovers and driver specific filters that all have an effect on phase after you have done the time alignment, and you do the PhaC on both side drivers, not only on one driver, and you do the PhaC on the crossover freqency, not an arbritary frequency that you see fit.
As allpass filters cause a frequency dependant delay they actually can work under these circumstances as you f.e. usually need to delay the highpassed speakers due to the phase shift caused by crossover slopes.
But again, it only works correctly if you're doing the time alignment as the very first step before setting driver specific filters including crossovers.

Problem is, you always have to measure if you really have an actual problem in this area after the car messed around with the acoustical phase due to all the reflections and stuff like that.

I personally listened to cars where the PhaC worked like expected and intended, but i also heared my own car where it didn't really work as expected and intended.
 

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However it still doesn’t change the facts we’ve both mentioned in that it doesn’t take into account any phase shift induced by the vehicle so may improve things or make it worse
One question (well, actually it's more than one...). Isn't this phase shift of the cars acoustics done to all drivers at the same time? F.e. in the area where you pass over the duty from midrange to tweeter?
If yes, the relative phase would stay the same even due to the induced phase shift by the car, right?
In this case, an allpass filter as created by either PhaC or the Helix phase control would still work as intended.
 

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Only if both drivers were in the exact same place in the car literally, even 5” centre to centre will change the reflections which will then potentially influence phase

this is why driver positioning and crossover freq have to be chosen very carefully
Yes, but these reflections will be the very same at all times, right? No matter if you set a crossover or driver specific filters, the reflections will be always the same and therefor relative phase will stay stable. It is not like the distance changes between drivers while listening.
Therefor this cannot be the answer. When i set the time alignment without crossovers (in theory that is, of course you need crossovers) the direct sound will all arrive in time, right?
When i set crossovers and driver specific filters arrival times will be changed, especially the lowpassed drivers will lag behind the highpassed drivers, no matter the always existing reflections. When i set an appropriate allpass filter on the highpassed speaker i can bring the arrival time back in time to the lowpassed speaker as the reflections will be stable.

Or is this way of thinking too simple?

Just trying to understand.
 

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Music is a lot of sine waves at once, which then, when overlayed, creates a not like sine wave looking wave, but still, technically it is all sine waves.
And these waves can be out of phase if played by two speakers, be it left+right or left midrange+left tweeter.
So getting the phase in order is really important in my opinion.
Time aligning the drivers before doing everything else makes sure, that every single frequency arrives at the listening position at the same time (plus/minus a few fractions of a milliseconds).
Adding driver filters to the aligned drivers creates phase problems as every single filter alters the phase at the listening position.
With the LR24dB filters the lowpassed driver is now one cycle behind in phase, but still in time.
Having a tool to bring them back in phase without altering the time alignment is now a handy tool, and allpass filters do exactly that.
If you have no allpass filters you can do the phase alignment also with time alignment, but time alignment then puts every frequency above or below the crossover area, depending which driver you are putting additional delay to, out of time with the frequencies of the other driver, except for the crossover region that is, because there you are back in phase and still in time.

And this is what PhaC (and the Helix phase adjuster) tries to do. It gives you an easy way to manipulate phase at the crossover region without affecting the time alignment of the different drivers.
Debate is on the technical implementation of the tool, not that allpass filters don't work.
 

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adding An AP midband or even slightly out of band on one driver in a multi way, like a right midbass for example, and not do it to the left or all the speakers , that is detrimental to the time domain. It might make one part better while messing other parts up
That's not how people should do it.
If you have a phase problem, you should make the good phase side similar to the bad phase side, not the bad phase side similar to the good phase side (as this is almost always impossible to do due to the environment). Result is same bad phase on both sides, which then negates the negatives that might occur when using allpass filters on one side only.
Ideally you wouldn't need an allpass filter, but a car is not an ideal environment, so sometimes you just have to use them.
 

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So you are pretending that it is impossible to have two drivers in phase and time in the crossover region and their passbands, right? Because if the lowpassed driver is lagging one cycle after applying the crossovers to both drivers they are in phase, but one cycle out of time. How do you solve that?
Just trying to understand.
 

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Ok, understood...
Another question.
When having a 3-way system with a typical midbass crossed at 60Hz highpass and 300Hz lowpass, do we need to account for the phase shift caused by the lowpass of the midbass in the highpass of the midbass region? When calculating the phase it seems that even with LR24dB filters in the highpass region you have a difference in phase of almost 30 degrees, or even more if you cross the lowpass lower (like in BMWs f.e.).
 
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