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Absolute Polarity in Mastering
Old 3rd July 2009
  #91
Gear Head
 

Quote:
Originally Posted by bob katz View Post
Oh yes they can, on the CD. Positive and negative-going polarity are unambiguously defined in PCM and it IS A STANDARD.
That's electrical polarity. It bears no connection to acoustic polarity, the topic here. Would that it did!

Quote:
And test signals are available for polarity testing on test CDs that I have that go back as far as 1981, with the CBS test disc. If you then make a positive-going digital signal become a positive going analong signal on pin 2 and using a polarity tester on your loudspeaker confirm it is positive-going, then your equipment has been calibrated.
Still must beg to differ. Digital or analog, a positive-going electrical signal may carry either (acoustic) polarity. As for using a tester on the loudspeaker, yes, that confirms it -- a CD or LP with consistently positive-going electrical polarity produces a mix of acoustic polarities.

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Don't go crazy on me. The CD is NOT DITTO.
????

Or is that crazy?

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It has an absolute standard.
How does that differ from a plain old standard?...

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If you take a sufficiently minimalist-miked recording which has been carefully checked to be in correct polarity,
That word again, "correct". With respect to what? What standard? If you're talking a tape recording, in Stodolski's now-ancient paper for IEEE Transactions on Audio it was made clear that none existed -- he proposed one, although it was never adopted.

Welcome to IEEE Xplore 2.0: The standardization of monaural phase

That's about as close as the world has ever come to standardizing the connection between electrical and acoustic polarities.

Quote:
then it will reproduce in correct polarity on my system and anyone elses.
Only if they have the same system!

Quote:
The standard is there. Don't go crazy on me with discussion of random polarities on different albums, I'm not even sure what exactly you are driving at (whether you are driving or the woofer, it's the same difference) and it doesn't matter a hoot.
Perhaps not to you. But the Stodolski paper referenced above claims that wrong polarity is more detectable that 11.5% IM distortion!

By the way, I am not just talking woofers.

Quote:
All that counts is that the elements are there. If there are random polarities on the recording it's the recording engineer's fault, not the reproduction equipment.
'Fraid it's far worse than that. There are interventions made down the line that they (apparently) know nothing of.

Quote:
Every microphone made in the last 40 years or so has calibrated polarity, every balanced microphone cable that's been properly made. I just don't know what you are trying to get at anymore, Clark.
[Sigh] I guess you must be right about that.

Quote:
But honestly, I ask simply, please respond to the EXACT assertions I have made, not go off on a tangent,
Sir, I have addressed the issues directly.

-- Acoustic polarity (née absolute polarity in this thread) matters because it is distinctly audible

-- However, a coherent system with coherent recordings is necessary.

-- On recordings this polarity comes in one or the other of only two dispositions, and either way works, sonically.

-- No standard exists for impressing acoustic polarity consistently on any recorded media, hence the random mixtures.

-- Acoustic polarity in a recording is unrelated to electrical polarity (alas).

-- To ease the situation for end users it would be extremely helpful for mastering engineers to 1) align all cuts and sections to one way or the other and 2) ascertain that down the road somewhere their plan isn't being fouled up.


Quote:
or I will have to abandon the thread, which has gone on long enough.
Not long enough for everyone to have arrived at an understanding!

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For DIGITAL sources I know EXACTLY which is correct.
So do I, whenever I listen.

Quote:
Haven't you heard of a polarity tester
I specified one earlier, remember?

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and standardized test signals?
Hmmm... maybe somewhere in the dim distant past... Thanks for reminding me.

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Just as frequency response can be calibrated with a sine wave, polarity can be calibrated with a positive-going (or negative if you wish) test signal and the right test equipment.
The right test signal and the right test equipment are fine, so long as one does not confuse the electrical and acoustic domains of polarity.

Quote:
It is of course not enough to know just a small amount, you also have to know how to measure the arrival time from the multiway loudspeakers, know what order the crossover is, and other things in order to know if the system can do a good job.
This is somewhat afield from the topic.

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Something which you assert as justification for the thing being nonsense.
"The thing"? What "thing"? I have asserted over and over that acoustic polarity is a critical parameter; what's "nonsense" is the claim that it's been brought under control.

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But please don't tell me even one more time that the CD is not a standard.
"The CD" ist niemals "a standard".

Not of polarity, not of sound.

(See? I changed the telling.)

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Once we entered the digital recording world, then we were able to define polarity, ABSOLUTELY CORRECTLY, thank you.
Argument by assertion! If you're right, then acoustic polarity should never vary on a CD. Yet, it does. How to explain?

Quote:
Yes, what's new. When did I say that the LP had an official standard? There was supposed to be a de facto standard... but I agree. In fact, I already asserted this in a previous post, in fact one of which you replied to, so please let's not go round and round and round in circles.
Your call.

Quote:
Where on earth do you get the idea that polarity varies 50/50 on CDs? By subjective judgment or objective? By comparing with the waveforms of genuine sources or by some idea in your head of what "sounds better"?
If I catch your drift, you're telling us that acoustic polarity is a chimera, unperceptible by ear. Just "some idea in your head". Well! That would mean this whole discussion is wasted, at least for you.

For what it's worth after that wet blanket being thrown on top, my own research (published in The Wood Effect) proves the 50/50 split on both LPs and CDs. I have confirmed these findings with the device (waveform detector) specified earlier. You are free to doubt this, or to call me a liar. Fine.

Others have also arrived at this conclusion, however, and published their results.

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Depending on your answer I'm outta here. Let's not get daft or crazy, ok?
You be da judge.

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Last but not least, let us not forget that the phenomenon is so subtle and nebulous most times that I just don't have time for any further argument.... good bye.
Good bye, and good... well never mind.

As for "subtle and nebulous", I see now where you're coming from. Either you have trouble hearing it, or your system scarcely reveals it. (Those are the usual two reasons for disparaging the phenomenon.) On the other hand, three published (or semi-published) studies conducted as DBTs (or better), have established audibility to the 99% confidence level. Not that that means that polarity is that allfired important, but it is suggestive. Also, everyone who crosses my threshold and is shown the right stuff, has come to appreciate its critical nature.

But you do need a minimum-phase reproducer and these are in short supply.

Hope that helps.

clark


BK[/QUOTE]
Old 3rd July 2009
  #92
Gear Head
 

Quote:
Originally Posted by Bob Olhsson View Post
Studios built since the '70s have paid pretty close attention to this. Prior to that it could be all over the map.
You are of course correct, regarding the alignments of electrical polarity... although in the Eighties a Recording engineer/producer magazine survey found the pin2/pin 3 situation among tape recorders to be... 50/50!

As for acoustic polarity, that has still not been brought under control.

clark
Old 3rd July 2009
  #93
Gear Head
 

Quote:
Originally Posted by Lagerfeldt View Post
...........And then a couple of people still insist on blabbering irrelevant nonsense, defending a book they wrote or acting like a sockpuppet.
Who, me?

What have I said that was "irrelevant"? Every word out of my mouth here has addressed the topic. There were no insults like "irrelevant".

As for who wrote the book, it would be more accurate to say that I assembled it (quite exhaustively) from sources -- of which there were well over 80 at the time in JASA, JAES, Re/p, Audio, Wireless World, IEEE Transactions on Audio, Mix and such. I used those to aduce my case, combined with some of my own original research. Did you know? Only one of the authors denied absolute polarity; the rest were firmly behind the concept. And did you know the first report came from Harvard, way back in 1952?

It's all quite interesting, perhaps you should read the book.

Quote:
I started this thread to hear how often other ME's checked for absolute polarity - not to start a moronic discussion questioning absolute polarity as a phenomenon or whether we can check and control it.
Far be it from me to "question absolute polarity as a phenomenon". As to "whether we can check and control it", of course we can!

We just simply don't.

clark
Old 3rd July 2009
  #94
Gear Head
 

Quote:
Originally Posted by Bob Olhsson View Post
............An amazing can of worms...
Yes. My very point, nearly.

And, when all those old tapes (some not so old) with indeterminate acoustic polarities are transferred to CD (or to LP reissues), they yield the variant results I've described. Yet, all results conform I expect to correct electrical polarity specs.

Again, the two types of polarity have not yet been conjoined. Hence the confusion.

clark
Old 3rd July 2009
  #95
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Quote:
Originally Posted by clarkjohnsen View Post
Yes. My very point, nearly.

And, when all those old tapes (some not so old) with indeterminate acoustic polarities are transferred to CD (or to LP reissues), they yield the variant results I've described. Yet, all results conform I expect to correct electrical polarity specs.

Again, the two types of polarity have not yet been conjoined. Hence the confusion.
Does beveling the edge of a CD or de-gaussing make the determination of polarity any easier?


DC
Old 4th July 2009
  #96
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Quote:
Originally Posted by dcollins View Post
Does beveling the edge of a CD or de-gaussing make the determination of polarity any easier?


DC
If not maybe replacing the stock power cord on the equipment with a $500 power cord might help.

If anyone is wondering what DC is getting at, here are a few quotes from Mr Johnsen:

Quote:
A few quotes:
"a new $3000 Audio Research preamp sounds rather poor until it’s hooked up with a $500 ESP power cord, and then it sounds great "
Quote:
"This writer [Clark Johnsen] has reported on such treatments since 1992, when in Stereophile he revealed that waving a tape degausser over CDs could greatly reduce their unpleasant edginess."
Quote:
"Often have I [Clark Johnsen] argued, that such tweaks belie the presumed expertise of our digital designers, besides illustrating that the current 16/44 system possibly may not require replacement, since we know neither what we already have, nor how it actually works."
Quote:
"it [Audio Desk Systeme] consists of a tightly belt-driven 4-inch turntable on which the CD is firmly clamped, then a sharp cutting tool applied by hand through a pivoted horizontal lever. The result: A perfectly true disc with a 30° beveled edge on which an ink film may be applied. Then when you listen, Omigod!"
Quote:
"Afterwards [after using the dio Desk Systeme] the music sounds more natural, more expressive, fuller, less edgy; and the musicians seem to be breathing easier. This applies not only to CDs, but to DVDs too, with clearer video!"
Quote:
"Approximately the same time as the news broke about CD "degaussing", the Bedinis introduced a hand-held battery-driven unit that replicated the phenomenon. Only, the effect lasted for only a few minutes and John claimed it wasn’t just about magnets anyway.

Something to do with... other radiation...

Subsequent versions improved on the initial concept and today the Bedini Dual-Beam Ultraclarifier presents an excellent remedy for the sonic ills of CD"
Quote:
"Benjamin Tape Eraser ($36), the original handheld device for cassettes and damn effective on CDs. Yes we know there is nothing ferric in a CD, thanks for pointing that out.
Quote:
Just try it, or the lesser but still serviceable Shack model. After waving the thing for 10 or 15 seconds closely over the disc, you will hear much less harshness and more articulate bass."
Quote:
"Optrix ($18), a polish for the business side of a disc, dramatically increases low-level resolution. With old analogue originals the hiss level rises, always a good sign. Products such as Esoteric Mist and TM-16 and others do the trick too."
Quote:
"Not to forget previous reports that digital gear can be greatly improved by ... specialty power cords. No minor matter, this, either."
Quote:
"While all the above serve to ameliorate the clattery, punishing aspect of CD audio, no one — credentialed academic, famous designer, prominent reviewer, experienced retailer nor myself — can say why. No one has the faintest notion."
Continue discussing at your own peril.

Alistair
Old 4th July 2009
  #97
kjg
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Quote:
Originally Posted by Lagerfeldt View Post
Just as the thread was about to die a horrible death it suddenly got interesting again.
It has been a roller coaster!
Old 4th July 2009
  #98
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I just love when people bring in other non relating subjects to a discussion when they havn't got anything to say, so PRO of you
Old 4th July 2009
  #99
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UnderTow's Avatar
 

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Quote:
Originally Posted by philip View Post
I just love when people bring in other non relating subjects to a discussion when they havn't got anything to say, so PRO of you
I think you will find that for most people, the quotes above will explain more about Mr Johnsen's posts than anything else he has written in this thread.

Alistair
Old 4th July 2009
  #100
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Quote:
Originally Posted by UnderTow View Post
I think you will find that for most people, the quotes above will explain more about Mr Johnsen's posts than anything else he has written in this thread.

Alistair
Well I still thinks it's very unprofessional, you could at least write down the source. But it would be even better if you could stay on topic. If you don't have anything to say you don't have to contribute you know.
Old 4th July 2009
  #101
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Quote:
Originally Posted by philip View Post
If you don't have anything to say you don't have to contribute you know.
Everything has been said. It is all very clear to anyone that understands basic logic.

This video comes to mind: YouTube - QualiaSoup's Channel

Alistair
Old 4th July 2009
  #102
Mastering
 

Quote:
Originally Posted by clarkjohnsen View Post

wrote: No standard exists for acoustic polarity.
I may regret not having said goodbye to this thread, but it's July 4th, I'm waiting for my wife to get dressed for a party, and I have nothing better to do, so here goes:

But yes there is. It is the standardization of microphone signals which absolutely equates incoming acoustical polarity with electrical polarity. For at least 60 years it's been working, pin 2 produces a positive going voltage with positive pressure on the mike diaphragm.

Next, MOST manufacturers of ADCs adhere to a standard which ensures that positive-going electrical voltage on pin 2 of the input (or the hot of the unbalanced input) produces an official positive-going digital signal. It would be illogical not to do otherwise since the correlation is obvious and the meaning of the word "positive" has been clearly defined in both the analog and digital domains. This is even easier to swallow than the more arbitrary microphone standard. And there may very well be an AES or IEC standard for ADCs which we should look up. But I am confident that the majority of ADCs which have been produced adhere to the standard.

It then stands to reason that because the microphone standard can be followed through to the Compact disc, and since there is an electrical standard that defines the polarity of the analog output of the compact disc, then there is a clear route for acoustic polarity all the way from the microphone to the reproducing loudspeaker, for digital recordings. It's far better than 50-50, since most loudspeaker manufacturers have been making + to yield outward going pressure for many years (with some exceptions, including my Lipinskis).

The issue with desiring minimum phase loudspeakers, desirable as it may be, is a side-trip point separate from the above.

And that's why your "50-50" idea for CDs sounds completely fishy, since most CDs have been made with microphones adhering to that standard for decades. Exactly what method of analysis have you used to determine that CDs are "50-50", in particular, compact discs made from all-digital recordings?

It is rather ironic that Mr. Johnsen belabors such outdated points in a forum to the mastering engineers who make the products. He keeps on repeating outdated issues going back to the days of analog and lumps CDs in with LPs based on some as-yet undefined tests he has made of the "acoustic wavefronts".

Quote:

'Fraid it's far worse than that. There are interventions made down the line that they (apparently) know nothing of.
As mastering engineers we are quite aware of all the possible interventions, but none of them deny the existence of a standard that does equate acoustical polarity at the point of origin with acoustical polarity at the point of reproduction!

Quote:

-- No standard exists for impressing acoustic polarity consistently on any recorded media, hence the random mixtures.
Here I beg to differ, in particular with respect to all-digital recordings, coupled with the aforementioned microphone standard which predated digital recording.

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-- Acoustic polarity in a recording is unrelated to electrical polarity (alas).
Not on the microphone side, and therefore all the way to the reproducer, once the non-standard analog recorders have been removed from the "50-50" equation.

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-- To ease the situation for end users it would be extremely helpful for mastering engineers to 1) align all cuts and sections to one way or the other and 2) ascertain that down the road somewhere their plan isn't being fouled up.
Which is exactly what we have been doing for years. The chances of us getting a recording which is in correct polarity are very high in these days of digital recording and standardized microphones, cables and consoles. However, ONLY by examining the waveform of certain known instruments in the DAW can we know for certain. But yes, listening on a coherent mastering reproduction system and trying both polarities can possibly settle some ambiguities, if the mastering engineer is skilled at the practice.

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The right test signal and the right test equipment are fine, so long as one does not confuse the electrical and acoustic domains of polarity.
The right test signal and the right test equipment DO transcend both the electrical and acoustic domains. I can easily generate a test signal in my DAW with a KNOWN polarity and then measure its acoustical polarity at my reproducers.

Quote:

Argument by assertion! If you're right, then acoustic polarity should never vary on a CD. Yet, it does. How to explain?
Au contraire, it's up to you to explain how you reached this conclusion. Are you judging CDs whose origin is known to you? And what method are you using to judge them? Furthermore, did the DBT tests which you cite first measure the distortion and non-linearity of the reproduction system? Because when that variable has been eliminated, it has been shown that in most cases, polarity differences in sawtooth waveforms no longer cause tonal differences, and when it had been thought it was the ear's sensitivity to polarity, it was rather the equipment's non-linearity that was causing ACTUAL tonal differences. This is easy to prove by other test methods as well. Regardless, I'm not denying the need to assert absolute polarity (my reproduction system is incredibly well time-aligned and reveals polarity differences quite well, thank you), simply denying your assertions that we do not have it well under control. Don't forget that you're writing in a forum where top-notch and technically-knowledgeable mastering engineers participate, this is not your Sunday hi-fi brunch.

Quote:

If I catch your drift, you're telling us that acoustic polarity is a chimera, unperceptible by ear. Just "some idea in your head". Well! That would mean this whole discussion is wasted, at least for you.
No, you clearly did NOT catch my drift. I have never denied the existence of absolute polarity nor its audibility. You can find my position in the second edition of my book on page 206: "In the real world, some musical instruments create very asymmetrical waveforms. The shape of the waveform should ideally be preserved from microphone through to the loudspeaker. The standard is that microphones produce a positive-going voltage on pin 2 when excited with an acoustic compression, which should produce an upward-going waveform in the DAW, and translate to a forward movement of the loudspeaker when reproduced. This means tha tthe system has correct absolute polarity. Is the phenomenon audible? On some systems it is extremely subtle, but it is possible to hear on certain highly coherent loudspeaker systems.

I produced an absolute polarity test for Chesky Records, using a solo trumpet recorded in a natural space with a Blmlein microphone pair. When the polarity is incorrect, the trumpet appears (to most listeners) about a meter further back. This is evidence that incorrect absolute polarity can affect how we mix and master."

And then I go on but enough quoting.

------------

It would be interesting to see how much further round and round Mr. Johnsen works to deny the logic of this thread. When you see me disappear, it is because I have reached the absolute conclusion that Mr. Johnsen's "polarity tester" is strictly in his head but not connected to any logic circuits!

BK
Old 4th July 2009
  #103
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Jeeze Bob!

How long does it take for your wife to get dressed?

Happy 4th.
Old 4th July 2009
  #104
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UnderTow's Avatar
 

Verified Member
Quote:
Originally Posted by Masterer View Post
Jeeze Bob!

How long does it take for your wife to get dressed?

Happy 4th.
Or, Jeeze Bob! How fast do you type!

Alistair
Old 5th July 2009
  #105
Mastering
 

Quote:
Originally Posted by UnderTow View Post
Or, Jeeze Bob! How fast do you type!

Alistair
Mary: "Bob, I'm ready to go!"

Bob: "Just a minute, I'm posting something on Gearslutz!"

(five minutes later)

Mary: "Bob, it's really time to go, now!"

Bob: "Hold on another minute, I'm almost done."

Oh, the patience of the angels :-).

BK
Old 5th July 2009
  #106
Mastering
 

I wrote "at least 60 years" for the microphone standard, but of course I meant "at least since 1960" for all mikes using the XLR connector.
Old 5th July 2009
  #107
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Verified Member
My thoughts on the topic... I rarely check for "absolute" polarity, most of the time it doesn't make much difference, and you just end up wasting the client's valuable time.

And to a degree, you need to respect the producers' wishes of what was delivered to you. Assuming that you are working with a real producer, and not just a bunch of guys on their first recording project, that have no idea what they're doing.

BUT once in a blue moon, when previewing a project that sounds noticeably lifeless and grey, I'll flip it, and if it gets better, I'll check with the producer, and we'll probably go with it.

I can count the times it's made a positive difference on one hand, and only once that the attending artists could really tell (sans placebo effect), and even claimed it "saved" the project : - )

I suppose it has to do with the punch of the kick and the attack o' the snare, whether the woofers are pushin' or pullin'. But with all the other instruments involved and of course Vocals, you may not want drums to dominate the track. There are too many variables to say really, nebulous to quantify, other than sound, feel, and if it makes your studio plants happy.

JT

p.s. I also support the "pin 2 as hot" standard.
Old 5th July 2009
  #108
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I wonder what and when the first mike to use an XLR connecter was. Probably some of the Shures.


Probably not anything commonly used in a recording studio before the EV RE series in the '60s. Opps, I forgot about the Shure 546 which was the predecessor of the venerable 57.
Old 7th July 2009
  #109
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Sorry to interrup in that great discussion between professional people... I have been reading the topic quickly and I have a few questions.. Sorry if I am a mere beetmakeur though :


1) Is that polarity or phase that has to do with whether the speaker membranes go up and down ?


2) I know it's mastering and not mixing, but is it wise to shift the phase of only one stereo channel ? I do that on my sinewave basslines and usually, I found it help getting with some mixing problems I have. The only thing is that so-called "phase cancellation" when it goes mono. But for the moment I have not enough experience so I never cared about that (using the Haas effect from time to time too, just experimenting)

3) I don't quite understand the difference between polarity and phase invertions even with what I tried to grasp upon the internet...
If I take a sinusoidal function, inverting the polarity is equivalent to have the negative value...
Yet, if i take the same sinusoidal function and I flipped its phase, it means I add 180 degrees to it... thus, it should give me the negative value too, doesn't it ?...(unless i made a mistake, waves physics and mathematics is 3 years behind me now lol)

4) I understand that with analog gear which might not be using any coax type wires you can get those polarity errors... what about all digital tracks ? there shouldn't be any difference ? unless all the recorded samples were at different polarities...

I just don't want to distract you all from the discussion so, i'm okay to have any answer you are willing to give by pms... Or if you have a great articles/books that explain in rather simple terms,

Thanks, and I am appreciative, I discovered gs by the rap forums, but im more interested in learning the technicalities, those are very interesting topics in here,
Old 7th July 2009
  #110
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UnderTow's Avatar
 

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Quote:
Originally Posted by B.A.S.E View Post

1) Is that polarity or phase that has to do with whether the speaker membranes go up and down ?
Short answer: Polarity.

Long answer: With a periodic wave you can also "invert the polarity" by shifting the phase by 180 degrees but you end up with a delayed signal. Depending on what you are doing, this might be an issue or not.

Quote:
2) I know it's mastering and not mixing, but is it wise to shift the phase of only one stereo channel ?
No! Unless you are looking for some weird effect.

Quote:
I do that on my sinewave basslines and usually, I found it help getting with some mixing problems I have.
This is a very bad idea! Maybe one of your speakers (or some other equipment in your system) is wired incorrectly?

Quote:
The only thing is that so-called "phase cancellation" when it goes mono.
Not just in mono, if you stand on a line stretching right between the two speakers it will also cancel out. Don't do it!

Quote:
3) I don't quite understand the difference between polarity and phase invertions even with what I tried to grasp upon the internet...
If I take a sinusoidal function, inverting the polarity is equivalent to have the negative value...
Not quite. See my other posts.

Quote:
Yet, if i take the same sinusoidal function and I flipped its phase, it means I add 180 degrees to it... thus, it should give me the negative value too, doesn't it ?...
Yes but it is time delayed while flipping the polarity doesn't change the timing. And as pointed out before, you can't shift the phase of a complex wave.

Quote:
4) what about all digital tracks ? there shouldn't be any difference ?
Not unless some piece of software/hardware is broken.

Si je peux te suggerer de relire mes messages precedants, les choses devraient se clarifier.

Alistair
Old 7th July 2009
  #111
Gear Head
 

Quote:
Originally Posted by dcollins View Post
Does beveling the edge of a CD or de-gaussing make the determination of polarity any easier?
Yes, as a rule. In fact, any treatment that makes a CD sound better (and boy do they need help!) makes polarity clearer.

Also I might add, LPs and tape tend to convey the polarity sense bettter than CD.

Further, even though one might think it should be otherwise, polarity switches in the digital domain have not in my experience been particularly effective in revealing the difference. Not that switches in the analog domain are much better!

clark
Old 7th July 2009
  #112
Gear Head
 

Quote:
Originally Posted by UnderTow View Post
If not maybe replacing the stock power cord on the equipment with a $500 power cord might help.
Ah, sarcasm... "Last refuge of the imaginativley bankrupt." "The refuge of the weak." "The refuge of a shallow mind."

Take your pick.

Quote:
If anyone is wondering what DC is getting at, here are a few quotes from Mr Johnsen:
I see I am being stalked by conventional wisdom -- a.k.a. received wisdom. These PC patrols are well known to me, as they have been nipping at my heels for decades. Pity they won't approach from the front with a stand-up-and-listen attitude, but then, these are hunters who believe, "I don't HAVE TO listen; I've read the book and I KNOW."

I must congratulate this particular trailsman on his wideranging sites, it must have been an enormous albeit satisfying effort to have gone through all the places my writing has appeared. But let's take a brief look at a couple of his finds.

Quote:
"Optrix ($18), a polish for the business side of a disc, dramatically increases low-level resolution. With old analogue originals the hiss level rises, always a good sign. Products such as Esoteric Mist and TM-16 and others do the trick too."
Who could really believe that an optical polish on an optical medium could ever improve matters, eh? The effrontery of that Johnsen!

Quote:
"it [Audio Desk Systeme] consists of a tightly belt-driven 4-inch turntable on which the CD is firmly clamped, then a sharp cutting tool applied by hand through a pivoted horizontal lever. The result: A perfectly true disc with a 30° beveled edge on which an ink film may be applied. Then when you listen, Omigod!"
What?! An off-center disc producing a strain on the read mechanism? Say it ain't so! THAT CAN'T BE! And reducing reflected light within the optical disc improves the reading? Please! You don't have to listen to know, THAT CAN'T BE!

Quote:
"While all the above serve to ameliorate the clattery, punishing aspect of CD audio, no one — credentialed academic, famous designer, prominent reviewer, experienced retailer nor myself — can say why. No one has the faintest notion."
And they still mostly don't.

Quote:
Continue discussing at your own peril.
No, the peril as always lies in refusing to listen.

clark
Old 7th July 2009
  #113
Gear Head
 

Quote:
Originally Posted by kjg View Post
It has been a roller coaster!
And you'll never forget a great ride!!

clark
Old 7th July 2009
  #114
Gear Head
 

Quote:
Originally Posted by philip View Post
I just love when people bring in other non relating subjects to a discussion when they havn't got anything to say, so PRO of you
And the "non relating subjects" are, what? I've concentrated on polarity; others, on personalities. Sad, for ones so, ah, PRO.

clark
Old 7th July 2009
  #115
Lives for gear
 
24-96 Mastering's Avatar
Quote:
Originally Posted by clarkjohnsen View Post

No, the peril as always lies in refusing to listen.

clark
Or maybe rather in refusing to listen blindly?


Oh, and it should be pointed out that you're attacking a straw man whereas Undertow was actually quoting you.
Old 7th July 2009
  #116
Gear Head
 

[QUOTE=bob katz;4346143]I may regret not having said goodbye to this thread, but it's July 4th, I'm waiting for my wife to get dressed for a party, and I have nothing better to do, so here goes:

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clarkjohnsen wrote: No standard exists for acoustic polarity.
What clarkjohnsen actually wrote was, "No standard exists for impressing acoustic polarity consistently on any recorded media." Does anyone not see the difference?

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But yes there is. It is the standardization of microphone signals which absolutely equates incoming acoustical polarity with electrical polarity. For at least 60 years it's been working, pin 2 produces a positive going voltage with positive pressure on the mike diaphragm.
All well and good, and I did mention that myself. But then we get to those nasty tape recorders (and more) where at least into the Eighties the inputs were split 50/50 in that regard. How you gonna take those recordings and make them consistent? I mean, as a mastering engineer.

I'd like to hear the answer.

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Next, MOST manufacturers of ADCs adhere to a standard which ensures that positive-going electrical voltage on pin 2 of the input (or the hot of the unbalanced input) produces an official positive-going digital signal. It would be illogical not to do otherwise since the correlation is obvious and the meaning of the word "positive" has been clearly defined in both the analog and digital domains. This is even easier to swallow than the more arbitrary microphone standard. And there may very well be an AES or IEC standard for ADCs which we should look up. But I am confident that the majority of ADCs which have been produced adhere to the standard.
That's great. Covers some territory. And it's good to know that we have a "majority" here -- I've always enjoyed seeing science done by consensus.

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It then stands to reason that because the microphone standard can be followed through to the Compact disc, and since there is an electrical standard that defines the polarity of the analog output of the compact disc, then there is a clear route for acoustic polarity all the way from the microphone to the reproducing loudspeaker, for digital recordings. It's far better than 50-50, since most loudspeaker manufacturers have been making + to yield outward going pressure for many years (with some exceptions, including my Lipinskis).
Yes, that "follow-through" -- how then does one account for the vastly irregular polarity situation actually encountered on CDs?

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The issue with desiring minimum phase loudspeakers, desirable as it may be, is a side-trip point separate from the above.
Not at all. Folks who do not listen over suitable speakers generally have a low regard for the importance of polarity, unto the point of sarcasm.

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And that's why your "50-50" idea for CDs sounds completely fishy,
Be that as it may, it's true.

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since most CDs have been made with microphones adhering to that standard for decades.
Flash: CDs are not made from microphones. They are made after a considerable amount of intervention, some of it unbeknownst to the mastering engineers. Not only that, but scads of CDs have been made from tape recordings, both analog and digital; where's your standard for those?

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Exactly what method of analysis have you used to determine that CDs are "50-50", in particular, compact discs made from all-digital recordings?
It all began, as it so often does, and really must, with listening. Later I confirmed all my findings with the device mentioned earlier. It's electronic. It's made for the purpose. It's vetted by meter-readers. What more could you ask?

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It is rather ironic that Mr. Johnsen belabors such outdated points in a forum to the mastering engineers who make the products.
With all due respect, they seem to need the help. 'Twas not Mr. Johnsen who brought the subject up, y'know.

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He keeps on repeating outdated issues
I'd have written "outworn shiboleths", but let it pass, let it pass.

Anyway, this discussion in your eyes I guess was outdated from the start, where Lagerfeldt wrote, "The question is not whether absolutely polarity exists or not, or if it can be hear or not. It can. The question was how often we as mastering engineers check for this during the mastering process."

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going back to the days of analog
Quelle horreur!

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and lumps CDs in with LPs
And tapes too. Don't forget tapes. I lumped 'em all!

Because they all can exhibit polarity, and polarity is the topic.

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based on some as-yet undefined tests he has made of the "acoustic wavefronts".
Yeah, when there's no such thing as "acoustic wavefronts". Is that the argument?

Lordy!

I have several times already defined the test, so try not to hang that around my neck any more.

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As mastering engineers we are quite aware of all the possible interventions, but none of them deny the existence of a standard that does equate acoustical polarity at the point of origin with acoustical polarity at the point of reproduction!
"Deny". No. No, they don't, since you put it that way. But likewise do none of them require or manifest a point-to-point relationship.

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Here I beg to differ, in particular with respect to all-digital recordings, coupled with the aforementioned microphone standard which predated digital recording.
Now we're down to "all-digital", from earlier, more general representations that "Of course there is a standard" and "In digital the polarity of a digital signal is absolutely defined and therefore can be applied at the analog end to the loudspeaker."

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Not on the microphone side, and therefore all the way to the reproducer, once the non-standard analog recorders have been removed from the "50-50" equation.
Aha! Narrowing the discussion down some more. I don't blame you. Unfortunately, mastering engineers in real life cannot be so choosy. And what is a mastering engineer? I looked it up:

A mastering engineer is one skilled in the practice of taking audio (typically musical content) that has been previously mixed in either the analog or digital domain as mono, stereo, or multichannel formats and preparing it for use in distribution, whether by physical media such as a CD, vinyl record, or as some method of streaming audio.

Looks like you're stuck with non-all-digital sources. Now back to the start of this thread: Lagerfeldt: "How often do you guys check and switch for the best polarity setting in mastering?"

I would delete the word "often" (the answer seems to be: never) and then assert that the important criterion is consistency, not "best".

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Which is exactly what we have been doing for years.
NOOOOOOOO....!!!

(Please forgive this outburst.)

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The chances of us getting a recording which is in correct polarity
"Correct" wrt. what, exactly?

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are very high in these days of digital recording and standardized microphones, cables and consoles. However, ONLY by examining the waveform of certain known instruments in the DAW can we know for certain. But yes, listening on a coherent mastering reproduction system and trying both polarities can possibly settle some ambiguities, if the mastering engineer is skilled at the practice.
Whew! But at last we got here. Big "if", tho'.

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The right test signal and the right test equipment DO transcend both the electrical and acoustic domains. I can easily generate a test signal in my DAW with a KNOWN polarity and then measure its acoustical polarity at my reproducers.
All well and good, but remember, some time back we were given the opinion that "Telarc always made sure that their bass drums would produce an outward-going woofer [excursion] for most impact."

I gather that view has been abandoned. Certainly no "standard" or procedure has yet been offered, that would even suggest that were possible, for Telarc or anyone.

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Au contraire, it's up to you to explain how you reached this conclusion.
Done.

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Are you judging CDs whose origin is known to you?
Sometimes, but why is that necessary?

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And what method are you using to judge them? Furthermore, did the DBT tests which you cite first measure the distortion and non-linearity of the reproduction system? Because when that variable has been eliminated, it has been shown that in most cases, polarity differences in sawtooth waveforms no longer cause tonal differences, and when it had been thought it was the ear's sensitivity to polarity, it was rather the equipment's non-linearity that was causing ACTUAL tonal differences.
I am not familiar with any peer-reviewed DBTs published in a reputable journal that prove your assertion.

See, two can play that game.

At any rate, that argument is not only a non-starter but is contradicted in the very next sentences.

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This is easy to prove by other test methods as well. Regardless, I'm not denying the need to assert absolute polarity (my reproduction system is incredibly well time-aligned and reveals polarity differences quite well, thank you),
That looks like beating a retreat from the earlier, "the phenomenon is subtle and nebulous." Very well, this discussion has produced a positive result.

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simply denying your assertions that we do not have it well under control. Don't forget that you're writing in a forum where top-notch and technically-knowledgeable mastering engineers participate, this is not your Sunday hi-fi brunch.
Wouldn't know, never been to one of those.

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No, you clearly did NOT catch my drift. I have never denied the existence of absolute polarity nor its audibility. You can find my position in the second edition of my book on page 206: "In the real world, some musical instruments create very asymmetrical waveforms. The shape of the waveform should ideally be preserved from microphone through to the loudspeaker. The standard is that microphones produce a positive-going voltage on pin 2 when excited with an acoustic compression, which should produce an upward-going waveform in the DAW, and translate to a forward movement of the loudspeaker when reproduced. This means tha tthe system has correct absolute polarity. Is the phenomenon audible? On some systems it is extremely subtle, but it is possible to hear on certain highly coherent loudspeaker systems.
Very good! So far as it goes, anyway, which is not far enough. However: "This means that the system has correct absolute polarity." No, sir. Systems don't have absolute polarity; they only have polarity.

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I produced an absolute polarity test for Chesky Records, using a solo trumpet recorded in a natural space with a Blumlein microphone pair. When the polarity is incorrect, the trumpet appears (to most listeners) about a meter further back. This is evidence that incorrect absolute polarity can affect how we mix and master."
Yes, the Chesky record. What it calls "incorrect" is at variance with some other test CDs I have, which call the same recorded polarity "correct".

What's a fellow to think?

About polarity in general, and about polarity on CD in particular?

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And then I go on but enough quoting.

------------

It would be interesting to see how much further round and round Mr. Johnsen works to deny the logic of this thread.
The logic, sir, has been one-sided, to that I will agree.

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When you see me disappear, it is because I have reached the absolute conclusion that Mr. Johnsen's "polarity tester" is strictly in his head
Again, for the umpteenth time, although I fear by now it will never penetrate:

SMART System 2000 Sound Check from Smart Cinerma Sound Products

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but not connected to any logic circuits!
Actually the thing has a little meter and set of lights on it. There must be some logic circuits inside, no?

clark
Old 7th July 2009
  #117
Gear Head
 

Quote:
Originally Posted by Jerry Tubb View Post
........................
BUT once in a blue moon, when previewing a project that sounds noticeably lifeless and grey, I'll flip it, and if it gets better, I'll check with the producer, and we'll probably go with it.
Exactly right. It "sounds noticeably lifeless and grey" is a perfect description of the phenomenon I call "the muffling distortion". Whichever, I must again be at pains to point out that that's over your system. When the CD reaches the customer's home, either it or his system may well be the opposite! You might as well have left it the way it was.

And so we're back to the major question I raise: Whatcha gonna do about it?

clark
Old 7th July 2009
  #118
Gear Guru
 
UnderTow's Avatar
 

Verified Member
Quote:
Originally Posted by clarkjohnsen View Post
Again, for the umpteenth time, although I fear by now it will never penetrate:

SMART System 2000 Sound Check from Smart Cinerma Sound Products
It seems to me, judging by this page: EZ Phase that the device can indeed test the absolute polarity of your system by using a test signal on the provided CD and using the hand held device. (Assuming they are not outright lying in the marketing). Nowhere on that page does it say it can test the absolute polarity of a random recording.

Have you been using this device on your collection of CDs and LPs and getting 50/50 (random) results and then concluding that CDs (or whatever) must have inverted polarity 50% of the time?


Alistair
Old 9th July 2009
  #119
Gear Head
 

Quote:
Originally Posted by UnderTow View Post
It seems to me, judging by this page: EZ Phase that the device can indeed test the absolute polarity of your system by using a test signal on the provided CD and using the hand held device. (Assuming they are not outright lying in the marketing). Nowhere on that page does it say it can test the absolute polarity of a random recording.
Indeed it doesn't, after I checked. But inasmuch as the item DOES perform that task, I should explain that it's sold as a device to align the polarity of drivers. (Unmentioned also in the literature: some drivers are intended to be out of phase with the others -- so one must be careful.) In fact it registers the polarity (compressive or rarefactive) of any transient musical signal in acoustic space.

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Have you been using this device on your collection of CDs and LPs and getting 50/50 (random) results and then concluding that CDs (or whatever) must have inverted polarity 50% of the time?
I have used it, yes, at first only to confrim that the list of particular polarities I published in The Wood Effect was true. (It was.)

If CDs and LPs are randomly dispersed in polarity, what else can one conclude, other than 50% are inverted from the other 50%? (Neither way, as I hope everyone has realized by now, is "correct" by any definition.)

Note too, the polarity of cuts across the entirety of the disc may vary as well.

Hope that helps.

clark

Last edited by clarkjohnsen; 9th July 2009 at 04:53 PM.. Reason: wrong words
Old 10th July 2009
  #120
Mastering
 

Quote:
Originally Posted by clarkjohnsen View Post

clark
Clark, you are destined to get completely random results using a Polarity tester in a manner which it was not designed. It is not possible to technically examine a complex musical waveform whose origin you do not know and determine by measurement if its polarity is correct or incorrect or even just one way or another.

BK
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