"Phil Allison" writes:

"cirejcon"

Phil Allison

I don't know what "reverse phase" means, but reversing the polarity
is EXACTLY THE SAME as a 180 degree phase shift at ALL frequencies;


** Completely stupid and wrong.

Polarity reversal is an instantaneous process - ie there is no time
delay.


Look, come back after you've taken a basic math class and don't be rude
if you don't have any idea what you're talking about.



** To have utterly failed to comprehend the issue - dickhead !!!!!

Phase shifting involves time delay between the original and the shifted
versions.

Polarity reversal does not.

They are equivalent, Phil.

Let g(t) = -1 * f(t), and let the Fourier transform of f(t) be F(w).
Then

G(w) = -1 * F(w)
= -1 * r(w) * e^{j*phi(w)}
= e^{j*pi} * r(w) * e^{j*phi(w)}
= r(w) * e^{j*(phi(w) + pi)}

In words, multiplying by -1 (polarity reversal) is equivalent to shifting
by a constant 180 degress (or pi radians), which is the same as performing
a frequency-dependent delay.

I know it doesn't seem right because you're not delaying anything in a sense,
but this is what the math says.
--
% Randy Yates % "And all that I can do
%% Fuquay-Varina, NC % is say I'm sorry,
%%% 919-577-9882 % that's the way it goes..."
%%%% % Getting To The Point', *Balance of Power*, ELO
http://home.earthlink.net/~yatescr

"Randy Yates"
"Phil Allison

I don't know what "reverse phase" means, but reversing the polarity
is EXACTLY THE SAME as a 180 degree phase shift at ALL frequencies;


** Completely stupid and wrong.

Polarity reversal is an instantaneous process - ie there is no time
delay.


Look, come back after you've taken a basic math class and don't be rude
if you don't have any idea what you're talking about.



** To have utterly failed to comprehend the issue - dickhead !!!!!

Phase shifting involves time delay between the original and the shifted
versions.

Polarity reversal does not.

They are equivalent, Phil.


** Then produce your *real world* device that performs the 180 degree
phase shift at all frequencies ( but is **NOT** a simple polarity reverser)
and demonstrate how it has NO time delay.

Keep in mind that the "frequency domain" is a fictional place where time
does not exist - so it does not exist.





............ Phil

Let g(t) = -1 * f(t), and let the Fourier transform of f(t) be F(w).
Then

G(w) = -1 * F(w)
= -1 * r(w) * e^{j*phi(w)}
= e^{j*pi} * r(w) * e^{j*phi(w)}
= r(w) * e^{j*(phi(w) + pi)}

In words, multiplying by -1 (polarity reversal) is equivalent to
shifting
by a constant 180 degress (or pi radians), which is the same as
performing
a frequency-dependent delay.

While your math is correct, I think you are misunderstanding. Start
with

x(t-a) - X(f)*exp(-j*2*pi*f*a)

which says that a phase *shift* for a particular frequency in the
frequency domain is equivalent to a time *shift* in the time domain.

Suppose you had two 60 second sinusoidal pulses of the same frequency,
one in the L channel and the other in the R channel and you wanted to
shift them 10 degrees out of phase with each other. What would you do?
You'd delay one of them and leave the other alone. And if you wanted
180 degrees phase shift you would increase the delay appropriately.
Flipping one channel is not the same since the two pulses no longer
lilne up in time.

What if you wanted 25*2*pi degrees phase shift? Now the pulses really
wouldn't line up. Would you leave both channels alone since

sin(phi) = sin(phi + 25*2*pi)

and call it done ?

Joe

I don't know about CoolEdit, but in Adobe Audition you simply select
/Effects/Filters/Graphic Phase Shifter... . That brings up a dialog with
various presets available, two of which are +90 and -90.

This is exactly the same with CoolEdit too. But when I applied it, it did
not sound the way I expected.

Bob


"Randy Yates" wrote in message
...

"Bob Pit" writes:

Hi

I am not very familiar with CoolEdit and I want to playback my voice (or
any
mp3 file) with a 90 degree phase offset between the 2 channels/speakers.
It
must be easy but how do you do this?

Thanks
Bob

Hi Bob,

I don't know about CoolEdit, but in Adobe Audition you simply select
/Effects/Filters/Graphic Phase Shifter... . That brings up a dialog
with various presets available, two of which are +90 and -90.

I found an audible difference on a section of Crosby, Stills, Nash,
and Young's old "Our House":

www.uspsdata.org/OurHouse90.wav
--
% Randy Yates % "Rollin' and riding and slippin' and
%% Fuquay-Varina, NC % sliding, it's magic."
%%% 919-577-9882 %
%%%% % 'Living' Thing', *A New World Record*,
ELO
http://home.earthlink.net/~yatescr

Perhaps this will give you a lead.

- With Cool Edit load the file as a two channel stereo.

- Show all the file on your screen.
- Select all the right channel
- Edit
- Cut

- Select all the left channel
- Edit
- Copy

- Pinpoint on the right channel screen only at a
place where you want to start the signal (Example 0,66 seconds)
- Edit
- Paste

Save the file and listen to it.


--
Allen Reny
http://www.a-reny.com

"Phil Allison" writes:

"Randy Yates"
"Phil Allison
Phase shifting involves time delay between the original and the shifted
versions.

Polarity reversal does not.

They are equivalent, Phil.


** Then produce your *real world* device that performs the 180 degree
phase shift at all frequencies ( but is **NOT** a simple polarity reverser)
and demonstrate how it has NO time delay.

Since you don't like my definition of phase shift [1], tell me how you
define it.

[1] Phase shift at frequency f for a continuous-time signal x(t) is
the angle in radians of the complex value of the Fourier transform of
the signal, X(f).
--
Randy Yates
Sony Ericsson Mobile Communications
Research Triangle Park, NC, USA
, 919-472-1124

"Bob Pit" writes:


I don't know about CoolEdit, but in Adobe Audition you simply select
/Effects/Filters/Graphic Phase Shifter... . That brings up a dialog with
various presets available, two of which are +90 and -90.

This is exactly the same with CoolEdit too. But when I applied it, it did
not sound the way I expected.

Hi Bob,

I forgot to mention one detail - in Audition you have an option to
apply the shift to both channels, the left channel, or the right
channel. I applied it to one channel (forget whether it was left or
right).

I saw another poster's response that seemed to imply that CoolEdit
doesn't have those options explicitly in the Graphic Phase Shifter
dialog window. Instead, it performs the phase shift on the selected
signal, so you must select just one channel of the stereo pair to get
a similar effect.
--
Randy Yates
Sony Ericsson Mobile Communications
Research Triangle Park, NC, USA
, 919-472-1124

"Randy Yates"
"Phil Allison"

Phase shifting involves time delay between the original and the
shifted
versions.

Polarity reversal does not.

They are equivalent, Phil.


** Then produce your *real world* device that performs the 180 degree
phase shift at all frequencies ( but is **NOT** a simple polarity
reverser)
and demonstrate how it has NO time delay.

Since you don't like my definition of phase shift [1],


** I could not give a **** about your asinine and circular definition -
esp. when posted posthumously.


The situation is very simple:


1. Your position is that "180 degrees of phase shift at all frequencies "
is identical to polarity reversal - OK ?

2. I agree. They are the same.

3. Occam's Razor requires that one must prefer the simplest, complete
explanation of a phenomenon - OK ?

4. Ergo, of the two - only phase inversion actually exists.




................ Phil

"Phil Allison" writes:

"Randy Yates"
"Phil Allison"

Phase shifting involves time delay between the original and the
shifted
versions.

Polarity reversal does not.

They are equivalent, Phil.


** Then produce your *real world* device that performs the 180 degree
phase shift at all frequencies ( but is **NOT** a simple polarity
reverser)
and demonstrate how it has NO time delay.

Since you don't like my definition of phase shift [1],


** I could not give a **** about your asinine and circular definition -
esp. when posted posthumously.

I propose that the more you use emotion and profanity in a response, the
weaker your position on the real issue is.

The situation is very simple:


1. Your position is that "180 degrees of phase shift at all frequencies "
is identical to polarity reversal - OK ?

2. I agree. They are the same.

3. Occam's Razor requires that one must prefer the simplest, complete
explanation of a phenomenon - OK ?

4. Ergo, of the two - only phase inversion actually exists.

This is an excluded-middle fallacy (http://en.wikipedia.org/wiki/False_dilemma).

You can actually build a circuit that will perform a frequency-dependent
delay of 180 degrees. Such a circuit can actually exist. The output
of such a circuit will be identical to a simple polarity reversal,
but the two implementations are not at all the same.
--
Randy Yates
Sony Ericsson Mobile Communications
Research Triangle Park, NC, USA
, 919-472-1124

"Laurence Payne" wrote in
message news
On Wed, 16 Mar 2005 00:04:33 +0200, "Bob Pit" wrote:

As for the "The modulation on the R channel is about 0.3 sec ahead
of the L channel", I cannpt figure how to do it (if it is not
already there).

If your wave editor has no control over the phase of a LFO signal, you
could do this. Split R and L channel as completely separate files.
Trim 0.3sec off the front of one file. Apply the modulation to each.
Now trim 0.3 sec off the other file and recombine them as stereo.

Later, having tried it out:

Amazingly, none of the wave editors I have here seem to have a simple
LFO function. Audition could probably do it with Convolution.
There's certainly a function to create a 1Hz sine wave, with control
over the initial phase.

There's also an amplitude modulation function in Audition.

"Randy Yates"
"Phil Allison"

Phase shifting involves time delay between the original and the
shifted
versions.

Polarity reversal does not.

They are equivalent, Phil.


** Then produce your *real world* device that performs the 180
degree
phase shift at all frequencies ( but is **NOT** a simple polarity
reverser) and demonstrate how it has NO time delay.

Since you don't like my definition of phase shift [1],


** I could not give a **** about your asinine and circular
efinition -
esp. when posted posthumously.

I propose that the more you use emotion and profanity in a response, the
weaker your position on the real issue is.


** Opinion presented as fact - ergo no case to answer.



The situation is very simple:


1. Your position is that "180 degrees of phase shift at all frequencies
"
is identical to polarity reversal - OK ?

2. I agree. They are the same.

3. Occam's Razor requires that one must prefer the simplest, complete
explanation of a phenomenon - OK ?

4. Ergo, of the two - only phase inversion actually exists.

This is an excluded-middle fallacy
(http://en.wikipedia.org/wiki/False_dilemma).



** Again, opinion presented as fact - ergo no case to answer.


You can actually build a circuit that will perform a frequency-dependent
delay of 180 degrees. Such a circuit can actually exist. The output
of such a circuit will be identical to a simple polarity reversal,
but the two implementations are not at all the same.


** Again, opinion presented as fact - ergo no case to answer.

A device that instantaneously reverses signal phase is a polarity inverter.

Any mention of phase shift is bunk.




................. Phil

"Phil Allison" writes:
[...]
A device that instantaneously reverses signal phase is a polarity inverter.

Any mention of phase shift is bunk.

You are using the term "phase shift." I have defined what I mean by
this term. I have shown how a polarity inverter modifies phase
shift as I defined it.

You have two options if you want to logically refute me:

1) Show that your definition of "phase shift" is not the same as
mine.

2) Show that my proof that polarity changes phase shift is flawed.

Until then, you are proving nothing but rather blowing hot air.
--
Randy Yates
Sony Ericsson Mobile Communications
Research Triangle Park, NC, USA
, 919-472-1124

Phil Allison wrote:
"Randy Yates"
"Phil Allison

I don't know what "reverse phase" means, but reversing the
polarity
is EXACTLY THE SAME as a 180 degree phase shift at ALL
frequencies;


** Completely stupid and wrong.

Polarity reversal is an instantaneous process - ie there is no
time
delay.


Look, come back after you've taken a basic math class and don't
be rude
if you don't have any idea what you're talking about.



** To have utterly failed to comprehend the issue - dickhead
!!!!!

Phase shifting involves time delay between the original and the
shifted
versions.

Polarity reversal does not.

They are equivalent, Phil.


** Then produce your *real world* device that performs the 180
degree
phase shift at all frequencies ( but is **NOT** a simple polarity
reverser)
and demonstrate how it has NO time delay.


Now you're just backpedaling. Obviously one is claiming this is a
sensible
way to globally reverse polarity, only that it is mathematically
equivalent.

As for a "real world device", the analog device would be - you guessed
it - a simple polarity reverser, also known as "180 degrees of phase
shift
at all frequencies".

It would be trivial to do digitially. There would be a delay, but
there is always a pipeline delay in digital signal processing, and
even analog signal filtering introduces delays of fractional
waves; however, since the ear can't distinguish fractions of a
wave, this doesn't matter (*please* don't say anything stupid about
hearing at this point. You'll only embarrass yourself).

Keep in mind that the "frequency domain" is a fictional place where
time
does not exist - so it does not exist.


Just because you don't understand something, doesn't mean it
doesn't exist.

You do realize that your ear works in frequency space (or are
you one of those rare people who can sense the position of their
eardrum as a function of time?)

You'd better stop. You're just making a fool out of yourself.

-jc





........... Phil

I forgot to mention one detail - in Audition you have an option to apply the
shift to both channels, the left channel, or the right channel. I applied it
to one channel (forget whether it was left or right).

This is exactly the way I did it in CoolEdit too. The effect was not what I
expected.


"Randy Yates" wrote in message
...

"Bob Pit" writes:


I don't know about CoolEdit, but in Adobe Audition you simply select
/Effects/Filters/Graphic Phase Shifter... . That brings up a dialog with
various presets available, two of which are +90 and -90.

This is exactly the same with CoolEdit too. But when I applied it, it
did
not sound the way I expected.

Hi Bob,

I forgot to mention one detail - in Audition you have an option to
apply the shift to both channels, the left channel, or the right
channel. I applied it to one channel (forget whether it was left or
right).

I saw another poster's response that seemed to imply that CoolEdit
doesn't have those options explicitly in the Graphic Phase Shifter
dialog window. Instead, it performs the phase shift on the selected
signal, so you must select just one channel of the stereo pair to get
a similar effect.
--
Randy Yates
Sony Ericsson Mobile Communications
Research Triangle Park, NC, USA
, 919-472-1124

You can do the same in CoolEdit with Effects - Delay Effects - Delay.

Bob


"Buzz" wrote in message
...

Perhaps this will give you a lead.

- With Cool Edit load the file as a two channel stereo.

- Show all the file on your screen.
- Select all the right channel
- Edit
- Cut

- Select all the left channel
- Edit
- Copy

- Pinpoint on the right channel screen only at a
place where you want to start the signal (Example 0,66 seconds)
- Edit
- Paste

Save the file and listen to it.


--
Allen Reny
http://www.a-reny.com

"Bob Pit" a écrit dans le message de news: 1110991026.533445@athnrd02...
You can do the same in CoolEdit with Effects - Delay Effects - Delay.

Bob

=============================================
Yes but that method cuts off the end of one of the channels
instead of preserving the whole length of the recording by adding
a silence at the end of the non delayed channel.

But, if it is not the effect that you are looking for, I am
really sorry about the disturbance.

--
Allen Reny
http://www.a-reny.com

"Randy Yates"
"Phil Allison"

A device that instantaneously reverses signal phase is a polarity
inverter.

Any mention of phase shift is bunk.

You are using the term "phase shift." I have defined what I mean by
this term. I have shown how a polarity inverter modifies phase
shift as I defined it.


** What a load of arrogant bull****.

No-one has the right to re-define matters in what ever artificial way they
like.

Get ****ed asshole.



.......... Phil