Phase shift

[BDWoody]

Ok,

Please do a write up for us ( no Google copy/paste) about absolute phase, minimum phase, excess phase and group delay....

But...take your time...no rush.

 

[maty]

As I wrote hours earlier in another thread, many years ago I decided not to write texts with some substance on the open Internet again. I also decided not to participate again in the net in Spanish.

 

[Julf]

As I wrote hours earlier in another thread, many years ago I decided not to write texts with some substance on the open Internet again.

But you are OK posting stuff without substance?

 

[Julf]

It is not my problem that many are confused about the phase, mixing concepts.

No, but the fact that you are confused about the phase, mixing concepts, is your problem.

 

[Matias]

In my understanding this is a no issue. Bruno already explained this, but again. The delay is constant in time for all frequencies. Only when you plot that constant time as a phase degree x frequency that it shows as a curve. But again these are constant delay in time for all frequencies. No problem.

@maty
I think my previous post may not have been understood correctly, so I spent a few minutes creating this spreadsheet and graph to illustrate my point.

I used 3 delays as examples: 1, 3 and 6 microseconds. Notice how the time delays are fixed by frequency, but since they compared against a decreasing wave period, they are plotted as phase curves.

Spreadsheet attached.

In other words, there is no problem with a constant, fixed delay for all frequencies. All frequencies arrive at your ear at the same time.

 

[Matias]

https://www.audiosciencereview.com/...-dual-mono-stereo-amp-review.9938/post-268273

Corrected results of Hypex NC400 is much worse!!!

https://www.audiosciencereview.com/...ments-of-hypex-nc400-diy-amp.5907/post-132771

First measurements: about 16º at 20 kHz. Corrected: 41º at 20 kHz.

In other words, the NC400 delays all frequencies 6 microseconds. This may be an issue with synching video and audio in a home theater, but for pure music listening with no video, no problem.

 

[maty]

https://www.diyaudio.com/forums/cla...ass-amplifiers-affects-sound-post5980879.html

Originally Posted by xrk971
Indeed, the folds in the human outer ear (pinna) introduces minute phase shifts of order 1-2usec. Our brain uses these phase shifts, which are asymmetric depending on orientation of sound relative to pinna (asymemtric), to determine directionality. This directionality does not depend on stereo reception. Try using one ear and see if you can hear direction from above or below or front or back. These shifts correspond to frequencies up to 300kHz. Hence, amps should be designed to be flat phase up to 300kHz or best spatial imaging.

https://www.diyaudio.com/forums/cla...ass-amplifiers-affects-sound-post5981631.html

[ This subject is very interesting. Especially because we´ve devolloped our own class D amp which has 0 dgr. phase shift troughout the audioband.

"We" are four guys who decided to do some cool electronics, end will be referred to as we. We have used ICEPower 1200AS2 as one of our references in the devellopment process just as well as nCore 500.

Our experience with the pretty large phase shift compared to 0 dgr´s is, that you obtain pretty much better 3D with no phase shift.

Also the sound seems more homogeneous in some sense. It is a bit more straight forward to listen to... ]

-> https://www.diyaudio.com/forums/class-d/345330-survey-class-project.html

 

[Julf]

amps should be designed to be flat phase up to 300kHz or best spatial imaging

Utter BS unless you are a bat.

 

[March Audio]

It is not my problem that many are confused about the phase, mixing concepts.

Maty you are the only confused person regarding this subject.

 

[March Audio]

https://www.diyaudio.com/forums/cla...ass-amplifiers-affects-sound-post5980879.html



https://www.diyaudio.com/forums/cla...ass-amplifiers-affects-sound-post5981631.html

[ This subject is very interesting. Especially because we´ve devolloped our own class D amp which has 0 dgr. phase shift troughout the audioband.

"We" are four guys who decided to do some cool electronics, end will be referred to as we. We have used ICEPower 1200AS2 as one of our references in the devellopment process just as well as nCore 500.

Our experience with the pretty large phase shift compared to 0 dgr´s is, that you obtain pretty much better 3D with no phase shift.

Also the sound seems more homogeneous in some sense. It is a bit more straight forward to listen to... ]

-> https://www.diyaudio.com/forums/class-d/345330-survey-class-project.html

OMG, you haven't even grasped the difference between phase shift being the same on both channels and different between channels.

@maty there is no phase accuracy in recordings. Think about how things are recorded.

 

[March Audio]

Utter BS unless you are a bat.

Indeed and again a confusion between timing and bandwidth.

So what are we to do considering cd is limited to 22kHz?

 

[March Audio]

In other words, the NC400 delays all frequencies 6 microseconds. This may be an issue with synching video and audio in a home theater, but for pure music listening with no video, no problem.

6 us is no issue at all for video sync, you might need 10 or 20 ms before it becomes noticeable.

 

[Matias]

You are right, I mixed them up, milliseconds are noticeable in synching, not microseconds.

 

[Deleted member 2944]

Complete inability to understand the difference between group delay and phase shift.
You guys are just wasting your breath trying to communicate. or edify, or explain, or whatever with maty on this topic.

This guy operates on multiple audio forums and has shown a complete lack of knowledge on many topics......not just this one.

Dave.

 

[pma]

@maty , would this phase response of the power amplifier be good enough for you?

 

[maty]

YES

-> At 20 kHz < 10º But it can be better.

Class AB amplifier?

 

[maty]

 

[Julf]

-> At 20 kHz < 10º But it can be better.

Do you think 10° at 20 kHz is audible?

 

[maty]

Maybe.

* But 40º or more (many class D amps) YES. With good acoustic recordings or with electrified instruments as guitars...

* Modern recordings, very bad produced and ALL with software instruments, voices with Autotune... NO.

 

[Julf]

* But 40º or more (many class D amps) YES. With good acoustic recordings or with electrified instruments as guitars...

At 20 kHz? I would love to see scientific evidence for that.