DiyMobileAudio.com Car Stereo Forum banner
1 - 20 of 67 Posts

·
Registered
Joined
·
81 Posts
Discussion Starter · #1 · (Edited)
so mosconi has a cool calculator of phase degree it's called phac(Phase Control shortcut and it is awesome.
this thing basically adjust the phase degree for getting better imaging and more precise stage.
u can learn more here:

EQ, T/A, isn't everything if u tune a system countless of times u will found everytime the instrument or the vocal doesn't sound natural something is a little bit off, even though everything else is perfect, the solution is for this situation.
most of the helix line up u have phase degree, most of the people don't use this option cuz they don't know how.
This is basically the secret sauce, the last 10% you can get from your system.
This is the closest u can get to FIR.
I was in shock after i tested this method, try and see for yourself, The stage got perfect and i mean perfect, all the sound became natural, the separation was spot on, it is the final destination.
This tutorial is an advancement tuning step, if u don't know all the other basics it won't help you.


So how we do it?
1. Download mosconi dsp tool.
2. Tune your system, Eq, Crossovers, Gains, Polarity check, ETC, (Don't T/A yet)
3. Open mosconi software and chose dsp with more Channels then yours dsp, my got 10 so i will chose aerospace 8/12, Chose work offline.
4. Import the setting from the Helix to the mosconi software - EQ and Crossovers.
5. this is the opne the freq chart
this graph calculate the phase shift after apply all the filter and the eq.
Computer Audio equipment Personal computer Font Screenshot


6. then chose the channel so u will see the phase and the phase which mark with red circles.
This is your starting point, before applying any changes, now you can close the cart.
Light Rectangle Font Slope Line


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"
Chose freq in the left i found that 400-1000 works the best but it depends on you settings.
Colorfulness Font Audio equipment Parallel Electronic device


8. The phac window opens, we will attached the mid L(ch3) to woofer L(Ch5) and so on, here u can see we got 81 degree change
WRITE THAT DOWN, everything the phac calculate write it so in the end u will import it to the helix/your dsp.
Colorfulness Font Screenshot Software Audio equipment


9.Then ch4->ch6(mids R to woofer R), Write that down and continue with the order from step 7,
Font Audio equipment Technology Electric blue Multimedia


10. in the end the result should look like that:
All the even channels are the same and the odd channel are the same(1-2 degree doesn't matter)
* On the subs channel 7-8 i made a mistake u should correcrt the degree to the same, one of the woofer doesn't matter which so be aware, both 7-8 should be 49/59 doesn't matter which degree target u chose.
Font Number


11. U can check the cart and see the phase is much better(I moddify the graph so u could understand better, after 180 degree the graph start from the top).
As u can see 100hz-3k is look much better alot closer to each other which mean better stagin,
compare this to the graph from step 6.
Colorfulness Rectangle Slope Plot Line


12. Import the phase degree u write down though the process we just did.
be aware degree bigger then 180 decrease 180
let's say the calculator give you 250 degree shift so you import in the helix 70(since 250-180=70)
Plus the helix tend to make steps of 5.6 degree so chose the closest one.
Font Rectangle Audio equipment Parallel Screenshot


13. T/A the system, i found that the helix auto T/A works perfect after 3-4 tries, make sure to use a enough volume in the T/A to the bar will be green otherwise it doesn't work that well.
If u have another processor make it manual though REW of Smaart(Or if u short on money - OpenSoundMeter which is like smaart but free and have the thing u need for T/A) But pleaseeee don't use the lame distance caculator it will not give you anything other then disappointment , if you want top natch system make your T/A the right way.
It's what make nice system to amazing system, this is how we connect speakers and make then into sound, a real sound.
I know zapco HDSP also has the phase shifter and I'm think on chaning the dsp soon.
If u know how to tune and u miss something, this is it, the last mile.

If u have any corrections/suggestion feel free.
I don't know anyone else who does this trick other then me.
U will be amazed.

I wrote it before i got to bed so there are some mistake in the tutorial i will fix everything tomrow...
 

·
Vendor
Joined
·
21,141 Posts
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.

2) you can (kinda) do this in the helix software already... see below

Font Line Rectangle Slope Mesh

Slope Line Font Rectangle Parallel
 
  • Like
Reactions: lpreston and vactor

·
Registered
Joined
·
81 Posts
Discussion Starter · #3 · (Edited)
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.

2) you can (kinda) do this in the helix software already... see below

View attachment 347814
View attachment 347815
1. it works for me... and all my people i know with Mosconi like the phac u can try it out.
it fix the phase shift made of the crossover and eq, plus it helps with the group delay so the result should be better sound stage.

2. I forgot about it i will check it but i don't think it will help u anyways.

Edit:
Checked it and it is not possible though the helix allpass display.

A demo of how it works with smaart:
 

·
Registered
Joined
·
517 Posts
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!).
 

·
Registered
Joined
·
517 Posts
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.
 

·
Registered
Joined
·
81 Posts
Discussion Starter · #6 · (Edited)
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!).
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.
 

·
Registered
Joined
·
4,103 Posts
Phac is purely electrical and not taking any acoustics into account or the influence of the cabin into account, so for me it’s a bit useless unless you happen to place crossovers in a minimum phase area ie the cabin has zero influence over the phase (highly unlikely)

it also assumes speaker phase is flat… it’s not and the midrange of the audio spectrum is always lagging from a driver and the sub bass and treble always leads

for want of a better description if you have a perfectly aligned two way home audio speaker the phase will generally look like a smiley face varying by 180 degrees at either end

So again phac doesn’t take the above into account
 

·
Registered
Joined
·
81 Posts
Discussion Starter · #8 ·
Yea I agree and this was my original though that it won’t help and you should adjust everything using Smaart which there you can see the impact of the acoustic environment on the phase very precisely.
But I’ve tried it and found that it works, so you can try calculate everything into you head, but something the realty is different.
I want some one with experience to try it and then check the impact it has.
 

·
Registered
Joined
·
4,103 Posts
Yea I agree and this was my original though that it won’t help and you should adjust everything using Smaart which there you can see the impact of the acoustic environment on the phase very precisely.
But I’ve tried it and found that it works, so you can try calculate everything into you head, but something the realty is different.
I want some one with experience to try it and then check the impact it has.
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
 

·
Registered
Joined
·
517 Posts
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.
 

·
Registered
Joined
·
517 Posts
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. ;)
 

·
Registered
Joined
·
81 Posts
Discussion Starter · #12 · (Edited)
Yea I know JL Tun is awesome this is based of smaart files, confirmed by a friend that works at JL, the licences to implante it cost them a lot.

and to cathul that is why I recommended t/a afterwards cuz the stage shifted from the center To the side from me. I’ve tried all Marks methods and I like him a lot, he is a crazy meniak, but this is just my personal preference.

and yes this is faster and more easy then tries various phase degrees.
If you have the time you can make it better? Absolutely, but this method seems to give me the best stage I have had plus u can done all the tuning in less than 2 hours with it.

anyways there isn’t any decent staging guide over here so I think it can be really helpful.
 

·
Registered
Joined
·
517 Posts
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.
 

·
Registered
Joined
·
81 Posts
Discussion Starter · #14 ·
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.
yep this guide is not dummy-proof u need to use your brain in some cases.
 

·
Registered
Joined
·
4,103 Posts
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. ;)
The phase slider in helix is designed to give x amount of phase shift at the crossover, so your not guessing anything, helix software does it for you
 

·
Registered
Joined
·
4,103 Posts
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.
You’d simply add delay to the midbass and everything above equally in that case or adjust the crossover slope and freq of the subwoofer a touch or the midbass, in reality 10 degrees is very little to adjust
 

·
Registered
Joined
·
4,103 Posts
Same with PhaC.
But we are talking about using smaart and other dsp softwares, why do I need phac, what does it offer me

with phac alone unless you can measure phase in the environment it’s not going to help as you will have to adjust after phac for the environment

phac can’t adjust anything automatically for the environment, so your left adjusting manually regardless
 

·
Vendor
Joined
·
21,141 Posts
Phac is purely electrical and not taking any acoustics into account or the influence of the cabin into account, so for me it’s a bit useless unless you happen to place crossovers in a minimum phase area ie the cabin has zero influence over the phase (highly unlikely)

it also assumes speaker phase is flat… it’s not and the midrange of the audio spectrum is always lagging from a driver and the sub bass and treble always leads

for want of a better description if you have a perfectly aligned two way home audio speaker the phase will generally look like a smiley face varying by 180 degrees at either end

So again phac doesn’t take the above into account
This is why I just do it by ear and rta
 
  • Like
Reactions: vactor

·
Registered
Joined
·
81 Posts
Discussion Starter · #20 ·
This is why I just do it by ear and rta
And this is why I made this guide - for people without trained ear.
Without 10 years experience.
Now they can make it too…
 
  • Like
Reactions: vactor
1 - 20 of 67 Posts
Top