phase reversing

[Matt]

When you reverse the phase of a sound, what exactly happens to the
waveform of the sound? I know what it sounds like, I just don't know
what happens in words. So what changes when I hit the little ø button
(I use pro tools so feel free to speak in the vocabulary).
Thanks--MAtt

[Paul Stamler]

"Matt" > wrote in message
om...
> When you reverse the phase of a sound, what exactly happens to the
> waveform of the sound? I know what it sounds like, I just don't know
> what happens in words. So what changes when I hit the little ø button
> (I use pro tools so feel free to speak in the vocabulary).

At the points where the air pressure should be increasing, it's now
decreasing, and vice versa. So the compressions get replaced by
rarefactions.

In the electrical wave which is the analog of the sound wave, what were
formerly positive excursions (increases in voltage) are now negative.

If you look at it on the screen, it's the vertical mirror-image of what it
useta be.

Peace,
Paul

[Paul Stamler]

"Matt" > wrote in message
om...
> When you reverse the phase of a sound, what exactly happens to the
> waveform of the sound? I know what it sounds like, I just don't know
> what happens in words. So what changes when I hit the little ø button
> (I use pro tools so feel free to speak in the vocabulary).

At the points where the air pressure should be increasing, it's now
decreasing, and vice versa. So the compressions get replaced by
rarefactions.

In the electrical wave which is the analog of the sound wave, what were
formerly positive excursions (increases in voltage) are now negative.

If you look at it on the screen, it's the vertical mirror-image of what it
useta be.

Peace,
Paul

[Pooh Bear]

Matt wrote:

> When you reverse the phase of a sound, what exactly happens to the
> waveform of the sound? I know what it sounds like, I just don't know
> what happens in words.

So !

Waiting with bated breath. What *does* it sound like to you ?


> So what changes when I hit the little ø button

Phase reverse actually means *invert the polarity*. So bits of the signal
that were previously positive going are now negative going and
vice-versa.


Graham

[Pooh Bear]

Matt wrote:

> When you reverse the phase of a sound, what exactly happens to the
> waveform of the sound? I know what it sounds like, I just don't know
> what happens in words.

So !

Waiting with bated breath. What *does* it sound like to you ?


> So what changes when I hit the little ø button

Phase reverse actually means *invert the polarity*. So bits of the signal
that were previously positive going are now negative going and
vice-versa.


Graham

[Harvey Gerst]

Pooh Bear > wrote:

>Matt wrote:
>
>> When you reverse the phase of a sound, what exactly happens to the
>> waveform of the sound? I know what it sounds like, I just don't know
>> what happens in words.

>So !
>Waiting with bated breath. What *does* it sound like to you ?

>> So what changes when I hit the little ø button

>Phase reverse actually means *invert the polarity*. So bits of the signal
>that were previously positive going are now negative going and
>vice-versa.
>Graham

So, instead of your music blowing, it now just sucks.

Harvey Gerst
Indian Trail Recording Studio
http://www.ITRstudio.com/

[Harvey Gerst]

Pooh Bear > wrote:

>Matt wrote:
>
>> When you reverse the phase of a sound, what exactly happens to the
>> waveform of the sound? I know what it sounds like, I just don't know
>> what happens in words.

>So !
>Waiting with bated breath. What *does* it sound like to you ?

>> So what changes when I hit the little ø button

>Phase reverse actually means *invert the polarity*. So bits of the signal
>that were previously positive going are now negative going and
>vice-versa.
>Graham

So, instead of your music blowing, it now just sucks.

Harvey Gerst
Indian Trail Recording Studio
http://www.ITRstudio.com/

[S O'Neill]

Pooh Bear wrote:

>
> Matt wrote:
>
>
>>When you reverse the phase of a sound, what exactly happens to the
>>waveform of the sound? I know what it sounds like, I just don't know
>>what happens in words.
>
>
> So !
>
> Waiting with bated breath. What *does* it sound like to you ?
>
>
>
>>So what changes when I hit the little ø button
>
>
> Phase reverse actually means *invert the polarity*. So bits of the signal
> that were previously positive going are now negative going and
> vice-versa.
>
>
> Graham
>


It's interesting how an electric bass played through speakers (no
headphones) gets deeper when you hit the polarity switch. And again
when you switch it back, sort of like a sonic M. C. Escher painting.

[S O'Neill]

Pooh Bear wrote:

>
> Matt wrote:
>
>
>>When you reverse the phase of a sound, what exactly happens to the
>>waveform of the sound? I know what it sounds like, I just don't know
>>what happens in words.
>
>
> So !
>
> Waiting with bated breath. What *does* it sound like to you ?
>
>
>
>>So what changes when I hit the little ø button
>
>
> Phase reverse actually means *invert the polarity*. So bits of the signal
> that were previously positive going are now negative going and
> vice-versa.
>
>
> Graham
>


It's interesting how an electric bass played through speakers (no
headphones) gets deeper when you hit the polarity switch. And again
when you switch it back, sort of like a sonic M. C. Escher painting.

[David Morgan \(MAMS\)]

"Harvey Gerst" > wrote in message ...
> Pooh Bear > wrote:
>
> >Matt wrote:
> >
> >> When you reverse the phase of a sound, what exactly happens to the
> >> waveform of the sound? I know what it sounds like, I just don't know
> >> what happens in words.
>
> >So !
> >Waiting with bated breath. What *does* it sound like to you ?
>
> >> So what changes when I hit the little ø button
>
> >Phase reverse actually means *invert the polarity*. So bits of the signal
> >that were previously positive going are now negative going and
> >vice-versa.
> >Graham
>
> So, instead of your music blowing, it now just sucks.
>
> Harvey Gerst
> Indian Trail Recording Studio
> http://www.ITRstudio.com/


Is this in the FAQ?

--
David Morgan (MAMS)
http://www.m-a-m-s DOT com
Morgan Audio Media Service
Dallas, Texas (214) 662-9901
_______________________________________
http://www.artisan-recordingstudio.com

[David Morgan \(MAMS\)]

"Harvey Gerst" > wrote in message ...
> Pooh Bear > wrote:
>
> >Matt wrote:
> >
> >> When you reverse the phase of a sound, what exactly happens to the
> >> waveform of the sound? I know what it sounds like, I just don't know
> >> what happens in words.
>
> >So !
> >Waiting with bated breath. What *does* it sound like to you ?
>
> >> So what changes when I hit the little ø button
>
> >Phase reverse actually means *invert the polarity*. So bits of the signal
> >that were previously positive going are now negative going and
> >vice-versa.
> >Graham
>
> So, instead of your music blowing, it now just sucks.
>
> Harvey Gerst
> Indian Trail Recording Studio
> http://www.ITRstudio.com/


Is this in the FAQ?

--
David Morgan (MAMS)
http://www.m-a-m-s DOT com
Morgan Audio Media Service
Dallas, Texas (214) 662-9901
_______________________________________
http://www.artisan-recordingstudio.com

[Laurence Payne]

On 12 Aug 2004 20:28:00 -0700, (Matt)
wrote:

>When you reverse the phase of a sound, what exactly happens to the
>waveform of the sound? I know what it sounds like, I just don't know
>what happens in words. So what changes when I hit the little ø button
>(I use pro tools so feel free to speak in the vocabulary).
>Thanks--MAtt


What DOES it sound like?

CubaseFAQ www.laurencepayne.co.uk/CubaseFAQ.htm
"Possibly the world's least impressive web site": George Perfect

[Laurence Payne]

On 12 Aug 2004 20:28:00 -0700, (Matt)
wrote:

>When you reverse the phase of a sound, what exactly happens to the
>waveform of the sound? I know what it sounds like, I just don't know
>what happens in words. So what changes when I hit the little ø button
>(I use pro tools so feel free to speak in the vocabulary).
>Thanks--MAtt


What DOES it sound like?

CubaseFAQ www.laurencepayne.co.uk/CubaseFAQ.htm
"Possibly the world's least impressive web site": George Perfect

[Chris Hornbeck]

On Thu, 12 Aug 2004 22:31:50 -0700, S O'Neill >
wrote:

>It's interesting how an electric bass played through speakers (no
>headphones) gets deeper when you hit the polarity switch. And again
>when you switch it back, sort of like a sonic M. C. Escher painting.

That's because you're moving ahead in time with each switch, by one
half cycle. If you do it enough you can take the next day off.

Well, it works for me anyway.

Chris Hornbeck

[Chris Hornbeck]

On Thu, 12 Aug 2004 22:31:50 -0700, S O'Neill >
wrote:

>It's interesting how an electric bass played through speakers (no
>headphones) gets deeper when you hit the polarity switch. And again
>when you switch it back, sort of like a sonic M. C. Escher painting.

That's because you're moving ahead in time with each switch, by one
half cycle. If you do it enough you can take the next day off.

Well, it works for me anyway.

Chris Hornbeck

[Mike Rivers]

In article > writes:

> What DOES it sound like?

Downloadable WAV and AIFF file here. Listen for yourself as the
polarity (not 'phase') switches midway through the playback.

http://www.recordingmag.com/downloads_audiopolarity.html


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> What DOES it sound like?

Downloadable WAV and AIFF file here. Listen for yourself as the
polarity (not 'phase') switches midway through the playback.

http://www.recordingmag.com/downloads_audiopolarity.html


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Paul Stamler]

"Mike Rivers" > wrote in message
news:znr1092402793k@trad...
>
> In article >
writes:
>
> > What DOES it sound like?
>
> Downloadable WAV and AIFF file here. Listen for yourself as the
> polarity (not 'phase') switches midway through the playback.
>
> http://www.recordingmag.com/downloads_audiopolarity.html

Mike:

Just curious -- have you ever listened to this file on a full-range
electrostatic speaker like a Quad ESL63? And was the polarity flip still
audible?

Peace,
Paul

[Paul Stamler]

"Mike Rivers" > wrote in message
news:znr1092402793k@trad...
>
> In article >
writes:
>
> > What DOES it sound like?
>
> Downloadable WAV and AIFF file here. Listen for yourself as the
> polarity (not 'phase') switches midway through the playback.
>
> http://www.recordingmag.com/downloads_audiopolarity.html

Mike:

Just curious -- have you ever listened to this file on a full-range
electrostatic speaker like a Quad ESL63? And was the polarity flip still
audible?

Peace,
Paul

[Don Pearce]

On Fri, 13 Aug 2004 15:04:51 GMT, "Paul Stamler"
> wrote:

>"Mike Rivers" > wrote in message
>news:znr1092402793k@trad...
>>
>> In article >
writes:
>>
>> > What DOES it sound like?
>>
>> Downloadable WAV and AIFF file here. Listen for yourself as the
>> polarity (not 'phase') switches midway through the playback.
>>
>> http://www.recordingmag.com/downloads_audiopolarity.html
>
>Mike:
>
>Just curious -- have you ever listened to this file on a full-range
>electrostatic speaker like a Quad ESL63? And was the polarity flip still
>audible?
>
>Peace,
>Paul
>

Even on headphones, the change is audible. I think thought that the
point is that it is only the change and a brief while afterwards that
is audible. Once it has settled down again, the sound is the same. If
you edit the file to reduce the volume just before the change, then
bring it up again afterwards, the effect vanishes.

d

Pearce Consulting
http://www.pearce.uk.com

[Don Pearce]

On Fri, 13 Aug 2004 15:04:51 GMT, "Paul Stamler"
> wrote:

>"Mike Rivers" > wrote in message
>news:znr1092402793k@trad...
>>
>> In article >
writes:
>>
>> > What DOES it sound like?
>>
>> Downloadable WAV and AIFF file here. Listen for yourself as the
>> polarity (not 'phase') switches midway through the playback.
>>
>> http://www.recordingmag.com/downloads_audiopolarity.html
>
>Mike:
>
>Just curious -- have you ever listened to this file on a full-range
>electrostatic speaker like a Quad ESL63? And was the polarity flip still
>audible?
>
>Peace,
>Paul
>

Even on headphones, the change is audible. I think thought that the
point is that it is only the change and a brief while afterwards that
is audible. Once it has settled down again, the sound is the same. If
you edit the file to reduce the volume just before the change, then
bring it up again afterwards, the effect vanishes.

d

Pearce Consulting
http://www.pearce.uk.com

[S O'Neill]

Chris Hornbeck wrote:

> On Thu, 12 Aug 2004 22:31:50 -0700, S O'Neill >
> wrote:
>
>
>>It's interesting how an electric bass played through speakers (no
>>headphones) gets deeper when you hit the polarity switch. And again
>>when you switch it back, sort of like a sonic M. C. Escher painting.
>
>
> That's because you're moving ahead in time with each switch, by one
> half cycle. If you do it enough you can take the next day off.
>
> Well, it works for me anyway.

Oh, man, since I read this about 3 seconds ago I've worn out a switch.
Now where did those two hours go?

[S O'Neill]

Chris Hornbeck wrote:

> On Thu, 12 Aug 2004 22:31:50 -0700, S O'Neill >
> wrote:
>
>
>>It's interesting how an electric bass played through speakers (no
>>headphones) gets deeper when you hit the polarity switch. And again
>>when you switch it back, sort of like a sonic M. C. Escher painting.
>
>
> That's because you're moving ahead in time with each switch, by one
> half cycle. If you do it enough you can take the next day off.
>
> Well, it works for me anyway.

Oh, man, since I read this about 3 seconds ago I've worn out a switch.
Now where did those two hours go?

[Laurence Payne]

On 13 Aug 2004 10:27:52 -0400, (Mike Rivers)
wrote:

>Downloadable WAV and AIFF file here. Listen for yourself as the
>polarity (not 'phase') switches midway through the playback.
>
>http://www.recordingmag.com/downloads_audiopolarity.html

Am I listening for the change-over , or for an audible difference
after the change?

CubaseFAQ www.laurencepayne.co.uk/CubaseFAQ.htm
"Possibly the world's least impressive web site": George Perfect

[Laurence Payne]

On 13 Aug 2004 10:27:52 -0400, (Mike Rivers)
wrote:

>Downloadable WAV and AIFF file here. Listen for yourself as the
>polarity (not 'phase') switches midway through the playback.
>
>http://www.recordingmag.com/downloads_audiopolarity.html

Am I listening for the change-over , or for an audible difference
after the change?

CubaseFAQ www.laurencepayne.co.uk/CubaseFAQ.htm
"Possibly the world's least impressive web site": George Perfect

[Arny Krueger]

"Laurence Payne" > wrote in
message
> On 12 Aug 2004 20:28:00 -0700, (Matt)
> wrote:
>
>> When you reverse the phase of a sound, what exactly happens to the
>> waveform of the sound? I know what it sounds like, I just don't know
>> what happens in words. So what changes when I hit the little ø button
>> (I use pro tools so feel free to speak in the vocabulary).
>> Thanks--MAtt
>
>
> What DOES it sound like?

http://www.pcabx.com/technical/polarity/index.htm

[Arny Krueger]

"Laurence Payne" > wrote in
message
> On 12 Aug 2004 20:28:00 -0700, (Matt)
> wrote:
>
>> When you reverse the phase of a sound, what exactly happens to the
>> waveform of the sound? I know what it sounds like, I just don't know
>> what happens in words. So what changes when I hit the little ø button
>> (I use pro tools so feel free to speak in the vocabulary).
>> Thanks--MAtt
>
>
> What DOES it sound like?

http://www.pcabx.com/technical/polarity/index.htm

[Arny Krueger]

"Laurence Payne" > wrote in
message
> On 13 Aug 2004 10:27:52 -0400, (Mike Rivers)
> wrote:
>
>> Downloadable WAV and AIFF file here. Listen for yourself as the
>> polarity (not 'phase') switches midway through the playback.
>>
>> http://www.recordingmag.com/downloads_audiopolarity.html
>
> Am I listening for the change-over , or for an audible difference
> after the change?

Try listening for both:

http://www.pcabx.com/technical/polarity/index.htm

[Arny Krueger]

"Laurence Payne" > wrote in
message
> On 13 Aug 2004 10:27:52 -0400, (Mike Rivers)
> wrote:
>
>> Downloadable WAV and AIFF file here. Listen for yourself as the
>> polarity (not 'phase') switches midway through the playback.
>>
>> http://www.recordingmag.com/downloads_audiopolarity.html
>
> Am I listening for the change-over , or for an audible difference
> after the change?

Try listening for both:

http://www.pcabx.com/technical/polarity/index.htm

[Pooh Bear]

Don Pearce wrote:

> On Fri, 13 Aug 2004 15:04:51 GMT, "Paul Stamler"
> > wrote:
>
> >"Mike Rivers" > wrote in message
> >news:znr1092402793k@trad...
> >>
> >> In article >
> writes:
> >>
> >> > What DOES it sound like?
> >>
> >> Downloadable WAV and AIFF file here. Listen for yourself as the
> >> polarity (not 'phase') switches midway through the playback.
> >>
> >> http://www.recordingmag.com/downloads_audiopolarity.html
> >
> >Mike:
> >
> >Just curious -- have you ever listened to this file on a full-range
> >electrostatic speaker like a Quad ESL63? And was the polarity flip still
> >audible?
> >
> >Peace,
> >Paul
> >
>
> Even on headphones, the change is audible. I think thought that the
> point is that it is only the change and a brief while afterwards that
> is audible. Once it has settled down again, the sound is the same. If
> you edit the file to reduce the volume just before the change, then
> bring it up again afterwards, the effect vanishes.

I was just thinking along those lines.

A truly instantaneous polarity reversal will create an impulse effect. A
'cross fade' between the original file and an inverted copy will produce a
brief null.

It doesn't seem possible to produce an instantaneous polarity change without
creating some transient effect which can doubtless be heard.


Graham

[Pooh Bear]

Don Pearce wrote:

> On Fri, 13 Aug 2004 15:04:51 GMT, "Paul Stamler"
> > wrote:
>
> >"Mike Rivers" > wrote in message
> >news:znr1092402793k@trad...
> >>
> >> In article >
> writes:
> >>
> >> > What DOES it sound like?
> >>
> >> Downloadable WAV and AIFF file here. Listen for yourself as the
> >> polarity (not 'phase') switches midway through the playback.
> >>
> >> http://www.recordingmag.com/downloads_audiopolarity.html
> >
> >Mike:
> >
> >Just curious -- have you ever listened to this file on a full-range
> >electrostatic speaker like a Quad ESL63? And was the polarity flip still
> >audible?
> >
> >Peace,
> >Paul
> >
>
> Even on headphones, the change is audible. I think thought that the
> point is that it is only the change and a brief while afterwards that
> is audible. Once it has settled down again, the sound is the same. If
> you edit the file to reduce the volume just before the change, then
> bring it up again afterwards, the effect vanishes.

I was just thinking along those lines.

A truly instantaneous polarity reversal will create an impulse effect. A
'cross fade' between the original file and an inverted copy will produce a
brief null.

It doesn't seem possible to produce an instantaneous polarity change without
creating some transient effect which can doubtless be heard.


Graham

[Pooh Bear]

Don Pearce wrote:

> Even on headphones, the change is audible. I think thought that the
> point is that it is only the change and a brief while afterwards that
> is audible. Once it has settled down again, the sound is the same.

Hmmm, maybe the cheap audio in my PC is to blame but I hear a curious effect.
The pulse train sounds unchanged but I hear a background low frequency tone
that appears to drop by perhaps a semitone after the polarity change.

Anyone else hear this.


Graham

[Pooh Bear]

Don Pearce wrote:

> Even on headphones, the change is audible. I think thought that the
> point is that it is only the change and a brief while afterwards that
> is audible. Once it has settled down again, the sound is the same.

Hmmm, maybe the cheap audio in my PC is to blame but I hear a curious effect.
The pulse train sounds unchanged but I hear a background low frequency tone
that appears to drop by perhaps a semitone after the polarity change.

Anyone else hear this.


Graham

[Pooh Bear]

Harvey Gerst wrote:

>
> So, instead of your music blowing, it now just sucks.

I was hoping someone would say that !


Graham

[Pooh Bear]

Harvey Gerst wrote:

>
> So, instead of your music blowing, it now just sucks.

I was hoping someone would say that !


Graham

[Mike Rivers]

In article > writes:

> Just curious -- have you ever listened to this file on a full-range
> electrostatic speaker like a Quad ESL63? And was the polarity flip still
> audible?

No. Send me one and I'll be happy to listen to it. <g>

What's your theory?

--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> Just curious -- have you ever listened to this file on a full-range
> electrostatic speaker like a Quad ESL63? And was the polarity flip still
> audible?

No. Send me one and I'll be happy to listen to it. <g>

What's your theory?

--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> Even on headphones, the change is audible. I think thought that the
> point is that it is only the change and a brief while afterwards that
> is audible. Once it has settled down again, the sound is the same. If
> you edit the file to reduce the volume just before the change, then
> bring it up again afterwards, the effect vanishes.

There they go, trying to make up reasons for why the demonstration
doesn't show what it's intended to demonstrate. Edit the file by
making it longer and it won't "settle down." I can clearly hear the
difference on my control room monitors, computer speakers, headphones,
or living room speakers when I play the Minirator polarity test signal
(similar sawtooth) through the system continuously and then reverse
the polarity.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> Even on headphones, the change is audible. I think thought that the
> point is that it is only the change and a brief while afterwards that
> is audible. Once it has settled down again, the sound is the same. If
> you edit the file to reduce the volume just before the change, then
> bring it up again afterwards, the effect vanishes.

There they go, trying to make up reasons for why the demonstration
doesn't show what it's intended to demonstrate. Edit the file by
making it longer and it won't "settle down." I can clearly hear the
difference on my control room monitors, computer speakers, headphones,
or living room speakers when I play the Minirator polarity test signal
(similar sawtooth) through the system continuously and then reverse
the polarity.


--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> Am I listening for the change-over , or for an audible difference
> after the change?

The changeover is pretty obvious. You should be listening for a
difference between the sound before and after the change.

--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> Am I listening for the change-over , or for an audible difference
> after the change?

The changeover is pretty obvious. You should be listening for a
difference between the sound before and after the change.

--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Logan Shaw]

Pooh Bear wrote:
> I was just thinking along those lines.
>
> A truly instantaneous polarity reversal will create an impulse effect. A
> 'cross fade' between the original file and an inverted copy will produce a
> brief null.
>
> It doesn't seem possible to produce an instantaneous polarity change without
> creating some transient effect which can doubtless be heard.

So record two tracks which have mutually opposite polarity, then
have a double-blind test. Ask listeners to record whether they
are listening to sound A or B. If you do this a lot and you get
a statistically-significant correlation (whether positive or negative),
you have shown strong evidence that they don't sound the same.

Seems like someone would have done this already...

- Logan

[Logan Shaw]

Pooh Bear wrote:
> I was just thinking along those lines.
>
> A truly instantaneous polarity reversal will create an impulse effect. A
> 'cross fade' between the original file and an inverted copy will produce a
> brief null.
>
> It doesn't seem possible to produce an instantaneous polarity change without
> creating some transient effect which can doubtless be heard.

So record two tracks which have mutually opposite polarity, then
have a double-blind test. Ask listeners to record whether they
are listening to sound A or B. If you do this a lot and you get
a statistically-significant correlation (whether positive or negative),
you have shown strong evidence that they don't sound the same.

Seems like someone would have done this already...

- Logan

[Pooh Bear]

Mike Rivers wrote:

> In article > writes:
>
> > Even on headphones, the change is audible. I think thought that the
> > point is that it is only the change and a brief while afterwards that
> > is audible. Once it has settled down again, the sound is the same. If
> > you edit the file to reduce the volume just before the change, then
> > bring it up again afterwards, the effect vanishes.
>
> There they go, trying to make up reasons for why the demonstration
> doesn't show what it's intended to demonstrate. Edit the file by
> making it longer and it won't "settle down." I can clearly hear the
> difference on my control room monitors, computer speakers, headphones,
> or living room speakers when I play the Minirator polarity test signal
> (similar sawtooth) through the system continuously and then reverse
> the polarity.

But is that perhaps due to the transducer as opposed to the ear ?

I don't know what *you* hear but do you hear the apparent 'pitch change' as I did ?


Graham

[Pooh Bear]

Mike Rivers wrote:

> In article > writes:
>
> > Even on headphones, the change is audible. I think thought that the
> > point is that it is only the change and a brief while afterwards that
> > is audible. Once it has settled down again, the sound is the same. If
> > you edit the file to reduce the volume just before the change, then
> > bring it up again afterwards, the effect vanishes.
>
> There they go, trying to make up reasons for why the demonstration
> doesn't show what it's intended to demonstrate. Edit the file by
> making it longer and it won't "settle down." I can clearly hear the
> difference on my control room monitors, computer speakers, headphones,
> or living room speakers when I play the Minirator polarity test signal
> (similar sawtooth) through the system continuously and then reverse
> the polarity.

But is that perhaps due to the transducer as opposed to the ear ?

I don't know what *you* hear but do you hear the apparent 'pitch change' as I did ?


Graham

[Scott Dorsey]

In article <znr1092422864k@trad>, Mike Rivers > wrote:
>
>In article > writes:
>
>> Just curious -- have you ever listened to this file on a full-range
>> electrostatic speaker like a Quad ESL63? And was the polarity flip still
>> audible?
>
>No. Send me one and I'll be happy to listen to it. <g>

Talk to sheldon at www.quadesl.com. He has a bunch of different kinds,
and he's a half-hour drive from you. And he is a very nice guy although
he does not like dim sum.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

In article <znr1092422864k@trad>, Mike Rivers > wrote:
>
>In article > writes:
>
>> Just curious -- have you ever listened to this file on a full-range
>> electrostatic speaker like a Quad ESL63? And was the polarity flip still
>> audible?
>
>No. Send me one and I'll be happy to listen to it. <g>

Talk to sheldon at www.quadesl.com. He has a bunch of different kinds,
and he's a half-hour drive from you. And he is a very nice guy although
he does not like dim sum.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Mike Rivers]

In article > writes:

> Hmmm, maybe the cheap audio in my PC is to blame but I hear a curious effect.
> The pulse train sounds unchanged but I hear a background low frequency tone
> that appears to drop by perhaps a semitone after the polarity change.

That's more precise than most people describe it, but it's the way
most people hear it.

If you're suspicious of the cue you get at the switchover, try making
a couple of longer loops of each polarity, or even constructing a pair
of test files yourself. Listen to one, then listen to the other.
You'll hear a difference in the low frequency content.

As I suggested, it could be an increase in apparent pitch when the
speaker cone is moving toward you rapidly when the waveform looks like
|\|\|\ as opposed to when it's moving toward you slower when the
waveform looks like |/|/|/

Doppler Effect? Something in the way our ears work? Or your own theory?
Either way, it sounds different when nothing other than the polarity
of the waveform changes. That demonstrates all I intended to
demonstrate.



--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> Hmmm, maybe the cheap audio in my PC is to blame but I hear a curious effect.
> The pulse train sounds unchanged but I hear a background low frequency tone
> that appears to drop by perhaps a semitone after the polarity change.

That's more precise than most people describe it, but it's the way
most people hear it.

If you're suspicious of the cue you get at the switchover, try making
a couple of longer loops of each polarity, or even constructing a pair
of test files yourself. Listen to one, then listen to the other.
You'll hear a difference in the low frequency content.

As I suggested, it could be an increase in apparent pitch when the
speaker cone is moving toward you rapidly when the waveform looks like
|\|\|\ as opposed to when it's moving toward you slower when the
waveform looks like |/|/|/

Doppler Effect? Something in the way our ears work? Or your own theory?
Either way, it sounds different when nothing other than the polarity
of the waveform changes. That demonstrates all I intended to
demonstrate.



--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Arny Krueger]

"Pooh Bear" > wrote in message



>> Even on headphones, the change is audible. I think thought that the
>> point is that it is only the change and a brief while afterwards that
>> is audible. Once it has settled down again, the sound is the same. If
>> you edit the file to reduce the volume just before the change, then
>> bring it up again afterwards, the effect vanishes.

> I was just thinking along those lines.

> A truly instantaneous polarity reversal will create an impulse
> effect. A 'cross fade' between the original file and an inverted copy
> will produce a brief null.

The PCABX comparator that you can download for free from www.pcabx.com has a
user-settable adjustement for dead time during the switchover.

> It doesn't seem possible to produce an instantaneous polarity change
> without creating some transient effect which can doubtless be heard.

Instantaneous changes aren't needed. You can't doddle and wait for 10
minutes, but something like a second won't hurt your ability to hear
differences. Since the changeover time is a user settable option, you can
check this out for yourself.

[Arny Krueger]

"Pooh Bear" > wrote in message



>> Even on headphones, the change is audible. I think thought that the
>> point is that it is only the change and a brief while afterwards that
>> is audible. Once it has settled down again, the sound is the same. If
>> you edit the file to reduce the volume just before the change, then
>> bring it up again afterwards, the effect vanishes.

> I was just thinking along those lines.

> A truly instantaneous polarity reversal will create an impulse
> effect. A 'cross fade' between the original file and an inverted copy
> will produce a brief null.

The PCABX comparator that you can download for free from www.pcabx.com has a
user-settable adjustement for dead time during the switchover.

> It doesn't seem possible to produce an instantaneous polarity change
> without creating some transient effect which can doubtless be heard.

Instantaneous changes aren't needed. You can't doddle and wait for 10
minutes, but something like a second won't hurt your ability to hear
differences. Since the changeover time is a user settable option, you can
check this out for yourself.

[Scott Dorsey]

Logan Shaw > wrote:
>
>So record two tracks which have mutually opposite polarity, then
>have a double-blind test. Ask listeners to record whether they
>are listening to sound A or B. If you do this a lot and you get
>a statistically-significant correlation (whether positive or negative),
>you have shown strong evidence that they don't sound the same.
>
>Seems like someone would have done this already...

They have, and the answer is that the audibility depends on the waveform
symmetry. On a horn there is a clear difference, on a kick drum there is
a clear difference, on a fiddle there is no real difference.

BUT, you could easily attribute that to asymmetry in the playback system
too, with a distortion that appears on a positive-going peak but not a
negative-going one. That would make absolute phase differences audible
but not necessarily significant.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Logan Shaw > wrote:
>
>So record two tracks which have mutually opposite polarity, then
>have a double-blind test. Ask listeners to record whether they
>are listening to sound A or B. If you do this a lot and you get
>a statistically-significant correlation (whether positive or negative),
>you have shown strong evidence that they don't sound the same.
>
>Seems like someone would have done this already...

They have, and the answer is that the audibility depends on the waveform
symmetry. On a horn there is a clear difference, on a kick drum there is
a clear difference, on a fiddle there is no real difference.

BUT, you could easily attribute that to asymmetry in the playback system
too, with a distortion that appears on a positive-going peak but not a
negative-going one. That would make absolute phase differences audible
but not necessarily significant.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Mike Rivers]

In article > writes:

> I don't know what *you* hear but do you hear the apparent 'pitch change' as I
> did ?

Yes. But I didn't want to give it away. That sometimes biases
observations.

--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> They have, and the answer is that the audibility depends on the waveform
> symmetry. On a horn there is a clear difference, on a kick drum there is
> a clear difference, on a fiddle there is no real difference.
>
> BUT, you could easily attribute that to asymmetry in the playback system
> too, with a distortion that appears on a positive-going peak but not a
> negative-going one. That would make absolute phase differences audible
> but not necessarily significant.

That's a way to create a waveform for which acoustic polarity is
audible from one for which it isn't, but that just proves that it's
possible to screw up audio. That's pretty obvious distortion and it's
easily discovered with conventional electronic test equipment. It's
also easy to verify that the test equipment is working correctly, not
giving a false indication, and not significantly interfering with the
measurement.

What we don't know (at least I don't) is whether a loudspeaker is
adding some form of distortion for which we don't have adequate test
equipment other than our ears. If we trust our ears, we have to
conclude that either the loudspeaker-air-molecule system is causing
distortion or that our hearing is indeed able to discriminate
polarity. You could put a microphone in front of the speaker, look at
its output, and would almost certainly see something resembling the
waveform being inverted when changing electrical polarity anywhere in
the system. But it wouldn't be identical in shape to the original
electrical waveform, so there's your easy-to-see distortion.

Now you have to prove that what you can observe can't be causing what
you hear, so it must be something else.



--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[S O'Neill]

Pooh Bear wrote:



> But is that perhaps due to the transducer as opposed to the ear ?



Why not? It doesn't seem likely that pushing a flexible cone gives the
same response as pulling it, even assuming magnetic gap uniformity,
ignoring varying impedance effects, and other stuff like that.