Absolute Polarity in Mastering

[MTStudios]

Originally Posted by philip

Thats great Bob, let me know how to do that. (find the "right" polarity in a usefull way)

If the positive section of a wave form a digital source results in the excusion of your speaker, I would say you have attained your absolute polarity reference. Now you're armed with the ability to make the "correct" decision in your mastering. You can only hope that the end user has their speakers aligned as such, but that's how mastering goes! Otherwise it's like saying "Well there's no point using an EQ on this master, because the listener might be boosting the bass on his home stereo!"

We can never make the "correct" decision on scientific terms, that's why engineers as scientists don't make very good engineers. It's all about using the resources you have to make the best ARTISTIC decisions while being equally aware of any technical concerns.

I'd say this falls under the artistic category, provided you've aligned your system to begin with. Does the music need more, or less "punch"/transients? I don't see how it's any different from any other mastering decision anyone ever has to make. Why do you have mastering speakers, and great DA's? Etc etc. Because you want the best reference to base your decisions on! And then you go and make a mixture of technical and artistic decisions. ARrgh!

I predict more and more consumer systems are going to become aware of this, it's easier to manage with digital.

[philip]

Originally Posted by Antman

If the positive section of a wave form a digital source results in the excusion of your speaker, I would say you have attained your absolute polarity reference. Now you're armed with the ability to make the "correct" decision in your mastering. You can only hope that the end user has their speakers aligned as such, but that's how mastering goes! Otherwise it's like saying "Well there's no point using an EQ on this master, because the listener might be boosting the bass on his home stereo!"

We can never make the "correct" decision on scientific terms, that's why engineers as scientists don't make very good engineers. It's all about using the resources you have to make the best ARTISTIC decisions while being equally aware of any technical concerns.

I'd say this falls under the artistic category, provided you've aligned your system to begin with. Does the music need more, or less "punch"/transients? I don't see how it's any different from any other mastering decision anyone ever has to make. Why do you have mastering speakers, and great DA's? Etc etc. Because you want the best reference to base your decisions on! And then you go and make a mixture of technical and artistic decisions. ARrgh!

I predict more and more consumer systems are going to become aware of this, it's easier to manage with digital.

YES, correct in theory but it has no practical use as I have pointed out several times by now. there are serveral problems, here is two.
1) you don't know the polarity of the source, the source is the mix wich can be and often are serveral tracks combined, you don't know the polarity of every track. Eg, you got a bassdrum and a bassline, the bassline is inverted to the bassdrum, do you invert the mix?

2) the loudspeaker itself changes the phase, sometimes up to several thousand degrees, there is no possibility for you to know the polarity of the end users system.

So, now you understand how it's different from a EQ.

[MTStudios]

Originally Posted by philip

YES, correct in theory but it has no practical use
1) you don't know the polarity of the source, the source is the mix wich can be and often are serveral tracks combined, you don't know the polarity of every track. Eg, you got a bassdrum and a bassline, the bassline is inverted to the bassdrum, do you invert the mix?

2) the loudspeaker itself changes the phase, sometimes up to several thousand degrees, there is no possibility for you to know the polarity of the end users system.

So, now you understand how it's different from a EQ.

1. The kick drum is too bassy, the bass needs more kick, what's the correct answer? No one can tell you, listen to what the song needs.

2. THe loud speaker at the consumer end has a big null@1.8k (make believe), but you just pulled that down 1.5dB and now it sounds great on your reference monitors! What're you going to do?

Your argument for point 1. is completely flawed. You're still trying to attain technically correct polarity. I'm arguing for artistically effective polarity. Perhaps the track calls for less punch in the drums and more in the bass? Or more in the bass and less in the drums? Now you've got an interesting choice to make


Maybe it's just me, but out of all the decisions in the mastering process, this seems the simplest one - flip the polarity, does the song feel better? If so, keep it, if not switch it back. Would take all of 10 seconds. The hardest part to me seems to be establishing the reference, but I think the work would pay off in the long run.

[philip]

Your argument for point 1. is completely flawed. You're still trying to attain technically correct polarity.

no thats what I am NOT doing.

There is no choice, you have no controll over polarity.

Go ahead, flip yourself tired, no one cares.

[clarkjohnsen]

Originally Posted by bob katz

It's not nonsensical when you supply the obvious missing parts that I thought would be obvious to an observer as perspicacious as you.

Who, me? That's your first mistake!

But I'll supply the missing parts of the paragraph:

Much appreciated.

1) Telarc ensured correct absolute polarity throughout their signal chain.

And I'll supply the antidote.

The term "absolute polarity" applies only in acoustic space; it denotes the correction of polarity that upon reproduction of a recording through a loudspeaker supplies the listener with the transient response of a real musical instrument, regardless how the polarity may be inscribed on the disc. All Telarc can do is make sure their electronics don't surreptitiously invert. Beyond that, how can they ensure that the groove excursion on their LP produces an outwards loudspeaker motion? How can they ensure that the Cd does likewise, when no standard exists for that?

Answers: they can't!

2) The statement about the bass drum assumes that the listener's reproduce system has been calibrated for correct absolute polarity. It's a syllogism.

More like a straw-man argument. Set it up, knock it down.

Fact is, there is no way in the world to calibrate a reproduce system so that it always produces "absolute polarity". Since it has been found that LPs are cut in either polarity willy-nilly, which way is right? Ditto CDs. How can a system be "calibrated" when the source is randomly distributed between the two polarities?

For example, until I discovered that my Lipinskis were incorrect, then signals put on the so-called plus terminal produce the incorrect polarity on the Telarc bass drum.

Why am I not surprised? But between the Lipinskis and the LP/CD, how do you know which is "incorrect"? Even more to the point, how do you know that any LP or CD is "correct"? Are you privy to information that the rest of us aren't?

3) In the analog days, since there was no official standard for magnetic coil polarity there was still a 50-50 chance of being right or wrong,

Pardon the interruption... but getting right down to the record, would you define an outwards-going groove excursion or an inwards-going one as yielding a positive wavefront? Since both have happened over time, and in the same 50/50 proportion, what good does it do to define just the cartridge?

By the way, as revealed in The Wood Effect, two different standards for the LP, one of them notional, were in effect during the Seventies. Guess what? They were opposites!

but in digital the polarity of a digital signal is absolutely defined and therefore can be applied at the analog end to the loudspeaker.

How do you imagine the digital signal is "absolutely defined"? Were that true, how could polarity vary so, on CDs? (Again, 50/50.) What's defined, I think, is the signal electrical polarity, not the acoustic polarity that is our topic here. There is no fixed relationship between the two.

4) Obviously the more minimalist the recording, the more that the acoustical wavefronts will align without ambiguity and throwing the thing into a mess.

Huh? How does lack of ambiguity end up producing a mess?

Also note, that when acoustic polarity was discovered in 1952 it was termed a monaural phase effect (MPE).

All this stands to reason but does not reduce the requirement that the loudspeakers themselves must be polarized correctly.

Fine, and there is at least a de facto standard here. But what about the huge amounts of phase shift designed into most loudspeakers? This "crossover catastrophe" obscures any sense of acoustic polarity, robbing music of its natural punch by substituting an ersatz "spaciousness".

I hope this supplies the obvious missing pieces and that we can move on from this nonsense.

This topic is "nonsense"? Nonsense!

clark

BK

[clarkjohnsen]

Originally Posted by philip

There is no choice, you have no controll over polarity.

Au contraire, you have choice, and therefore you have control.

Go ahead, flip yourself tired, no one cares.

As we can see, that isn't quite true. ;-)

clark

[clarkjohnsen]

Originally Posted by Antman

1. You're still trying to attain technically correct polarity. I'm arguing for artistically effective polarity. Perhaps the track calls for less punch in the drums and more in the bass? Or more in the bass and less in the drums? Now you've got an interesting choice to make

There is considerable irony here. Say that over your studio monitor you mix a drum with reverse polarity to make it less punchy -- when the music finally arrives at the listener the probability is 50% that it will manifest as a far punchier drum, with the rest of the material recessed.

Maybe it's just me, but out of all the decisions in the mastering process, this seems the simplest one - flip the polarity, does the song feel better? If so, keep it, if not switch it back. Would take all of 10 seconds. The hardest part to me seems to be establishing the reference, but I think the work would pay off in the long run.

Except that... you don't know what the long run will do to the signal! At some point you lose control of it forever.

clark

[UnderTow]

Originally Posted by clarkjohnsen

All Telarc can do is make sure their electronics don't surreptitiously invert.

"All Telarc can do..." And that is all they need to have done to make Bob Katz' comment accurate. He never mentioned any voodoo or anything else. Why are you pretending he did? Talking about strawman arguments...

Fact is, there is no way in the world to calibrate a reproduce system so that it always produces "absolute polarity". Since it has been found that LPs are cut in either polarity willy-nilly, which way is right? Ditto CDs. How can a system be "calibrated" when the source is randomly distributed between the two polarities?

The fact that many releases have polarity errors on them is irrelevant. Those are errors on the LPs and CDs, not in the system used to reproduce them. More straw....

Even more to the point, how do you know that any LP or CD is "correct"? Are you privy to information that the rest of us aren't?

Lupo posted a picture of the initial attacks of the kick drums in the wave I posted earlier. How can there be any doubt as to which is correct and which isn't?

How do you imagine the digital signal is "absolutely defined"? Were that true, how could polarity vary so, on CDs? (Again, 50/50.)

Non sequitur of monumental proportions.

Or are you just here to prove that your book isn't outdated? Did your publisher put you up to this?

What's defined, I think, is the signal electrical polarity, not the acoustic polarity that is our topic here. There is no fixed relationship between the two.

There is no fixed relationship if people don't care. If care is taken to keep the electrical polarity of the recording/mixing/mastering chain then that realtionship does exist.

Alistair

[philip]

Originally Posted by UnderTow

There is no fixed relationship if people don't care. If care is taken to keep the electrical polarity of the recording/mixing/mastering chain then that realtionship does exist.

Alistair

well, thats pretty much what i said in my first post... wich is the second post in this thread...

but that won't happen anyway so it's a non issue.

[dave-G]

Not to interrupt all the spirited theory going on here, but FWIW, I'm mastering a track right now that's got a visible negative offset (not to mention negative transients) and it sounds better inverted.

There, I said it.

-dave

[Nordenstam]

Let me restate how I personally found that most CD's have a certain polarity. It was after buying a new monitor converter that output pin 3 hot. Luckily, the converter have a polarity switch attached. After playing around with it for a while, it soon became obvious that most CD's sounded better with the switch in the inverting position. Made perfect sense as I RTFM and discovered that the XLR output was inverted in regard to what I expected. I phoned a friend that already had bought the converter a while before me. Turned out that he had the exact same experience when he started using it. Most CD's are produced with a correct(and therefore best sounding) polarity. Some are wrong, most aren't.

To those of you who don't believe in a certain polarity: why do you think amps and speaker terminals are marked with positive and negative? The fact that some systems get this wrong does not make it right to have the polarity inverted. It's a technical error.

As previously noted, whatever the phase shift is around the crossover point, it's very hard to imagine that it can invert a transient. Phase shift in the crossover zone wont flip the signal upside down. Please mic up your speakers and try. If you can post a clip proving your point, I'll be very impressed and duly humbled!

[Nordenstam]

Googled for speaker phase response and found this: http://www.bksv.com/doc/17-198.pdf

Haven't read it all, yet, but the pictures are interesting. Where's the thousand of degrees of phase errors?

[bob katz]

Originally Posted by clarkjohnsen

Who, me? That's your first mistake!


And I'll supply the antidote.

The term "absolute polarity" applies only in acoustic space; it denotes the correction of polarity that upon reproduction of a recording through a loudspeaker supplies the listener with the transient response of a real musical instrument, regardless how the polarity may be inscribed on the disc. All Telarc can do is make sure their electronics don't surreptitiously invert. Beyond that, how can they ensure that the groove excursion on their LP produces an outwards loudspeaker motion? How can they ensure that the Cd does likewise, when no standard exists for that?

Answers: they can't!

Oh yes they can, on the CD. Positive and negative-going polarity are unambiguously defined in PCM and it IS A STANDARD. 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.

Fact is, there is no way in the world to calibrate a reproduce system so that it always produces "absolute polarity". Since it has been found that LPs are cut in either polarity willy-nilly, which way is right? Ditto CDs. How can a system be "calibrated" when the source is randomly distributed between the two polarities?

Don't go crazy on me. The CD is NOT DITTO. It has an absolute standard. If you take a sufficiently minimalist-miked recording which has been carefully checked to be in correct polarity, then it will reproduce in correct polarity on my system and anyone elses. 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. 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.

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. But honestly, I ask simply, please respond to the EXACT assertions I have made, not go off on a tangent, or I will have to abandon the thread, which has gone on long enough.

Why am I not surprised? But between the Lipinskis and the LP/CD, how do you know which is "incorrect"? Even more to the point, how do you know that any LP or CD is "correct"? Are you privy to information that the rest of us aren't?

For DIGITAL sources I know EXACTLY which is correct. Haven't you heard of a polarity tester and standardized test signals? 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.

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. Something which you assert as justification for the thing being nonsense. But please don't tell me even one more time that the CD is not a standard. Once we entered the digital recording world, then we were able to define polarity, ABSOLUTELY CORRECTLY, thank you.

Pardon the interruption... but getting right down to the record, would you define an outwards-going groove excursion or an inwards-going one as yielding a positive wavefront? Since both have happened over time, and in the same 50/50 proportion, what good does it do to define just the cartridge?

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.

How do you imagine the digital signal is "absolutely defined"? Were that true, how could polarity vary so, on CDs? (Again, 50/50.) What's defined, I think, is the signal electrical polarity, not the acoustic polarity that is our topic here. There is no fixed relationship between the two.

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"?

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

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.


BK

[turtlerock]

what is interesting to me is the that on this forum we can ALL claim to hear this phenomena (i will let you guys argue about what it is called ),

they are many trains of thought out there that believe you just cannot hear this !
and some believe strongly that to be a proven fact you cannot hear it
i have not read or to date even heard of clarks book (wood effect ) , but it sounds like he has done the hard yards in putting it together

i wrote a magazine article once not too long ago , indicating my surprise that a particular set of speakers made this phenomena a night / day experience (yeah ..duntech soveigns actually )
i discovered my bryston amps were wired pin three hot which i had not known or detected before by testing these speakers out .

anyway i got a bunch of electrical engineers responding to my article citing all kinds of test and historical references that state you just cannot hear this effect , i contacted each guy and asked them personally if they had ever heard a speaker in the order of duntechs or similar

each guy said no of course they had not .

but they maintained it was an electronic non issue based on their prior learning

now we can all "see" this stuff on our DAW, we can test for it with our gadgets
we can hear it with our high grade speakers .

why on earth would we choose to say there is no standard so lets just forget about it

there is no way that on any recording i ever see that the absolute (p) is a 50/50 bet ,

i would consider it more like a 70/30 which indicates to me the world is well on the way to making sure everything starts and stops in the same way in the master recordings .

is the consumer still running a 50 /50 bet on absolute polarity ..? yes sure

but which consumers can hear 40 hz on their speakers ... 5 % ?
yet as mastering types we sort the bottom end out all day every day to taste -
there is no standard there either.

my feeling is there are so many other more important sonic issues we have to deal with then absolute (p) but in the washup you must do all the dishes ... right ?
or you just run a messy kitchen

[dcollins]

Originally Posted by bob katz

Once we entered the digital recording world, then we were able to define polarity, ABSOLUTELY CORRECTLY, thank you.

This was certainly possible even in analog!

All you needed was a test signal with a known polarity (sine wave through a diode was popular) and you could look at each section in turn to verify the direction.

The phase popper was developed to verify the phasing of multi-miced setups in the studio, not for loudspeaker design aiui. Also in some speakers with a 12dB/octave crossover the tweeter is wired out of phase with the woofer, so if you were to hold the receiver side of the phase popper close to each driver you would see a different result.

As Turtlerock mentioned, all we can really do in mastering is to insure that polarity is maintained in the chain. There is one actual advantage to digital here, as flipping polarity comes with no sonic cost, as there is no extra contact or inverting stage as there would be in analog.

DC

[bob katz]

Originally Posted by dcollins

This was certainly possible even in analog!

All you needed was a test signal with a known polarity (sine wave through a diode was popular) and you could look at each section in turn to verify the direction.

Yup, you could, but there was no standard that "north" is "plus" and "south" is "minus" for example, so you had a 50-50 chance as far as the rest of the world is concerned.

The phase popper was developed to verify the phasing of multi-miced setups in the studio, not for loudspeaker design aiui. Also in some speakers with a 12dB/octave crossover the tweeter is wired out of phase with the woofer, so if you were to hold the receiver side of the phase popper close to each driver you would see a different result.

Yup!

As Turtlerock mentioned, all we can really do in mastering is to insure that polarity is maintained in the chain.

And hope that the clients are using correct polarity, which is much more likely now with digital at the preamp side. Then, as long as they hook the red speaker terminal to the red amp terminal, which most people have been doing for years. Anyway, I don't worry about it much, I don't have clients who are that anal, I'm anal enough for them all :-).

BK

[Bob Olhsson]

Studios built since the '70s have paid pretty close attention to this. Prior to that it could be all over the map.

[Adam Dempsey]

Originally Posted by Lagerfeldt

One half sounds right, one half sucks, literally speaking. ;-)

I think that's a very clear example.

Agreed.. the change is obvious with a slight smearing & 'distance' in the second half of that example.

[Lagerfeldt]

Yes, it's interesting that the change isn't just a question of punch and low end but also one of distance perception. Clearly demonstrated in Alistair's audio file.

I also find it intriguing that:

· Just about everybody can hear the effect
· It's possible to check it yourself, and assuming the playback systems are setup correctly:
· It's reproducible and therefore controllable

And then a couple of people still insist on blabbering irrelevant nonsense, defending a book they wrote or acting like a sockpuppet.

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.

[24-96 Mastering]

Originally Posted by Lagerfeldt

sockpuppet

What a beautiful word... and concept.

[philip]

Originally Posted by dcollins

As Turtlerock mentioned, all we can really do in mastering is to insure that polarity is maintained in the chain. There is one actual advantage to digital here, as flipping polarity comes with no sonic cost, as there is no extra contact or inverting stage as there would be in analog.

DC

exactly, and the only way to insure that the polarity is maintained... is to do nothing.

[philip]

Originally Posted by Lagerfeldt

Yes, it's interesting that the change isn't just a question of punch and low end but also one of distance perception. Clearly demonstrated in Alistair's audio file.

I also find it intriguing that:

· Just about everybody can hear the effect
· It's possible to check it yourself, and assuming the playback systems are setup correctly:
· It's reproducible and therefore controllable

And then a couple of people still insist on blabbering irrelevant nonsense, defending a book they wrote or acting like a sockpuppet.

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.

I checked the phase on your speakers and came up with this from KH site:


You do have some phase distortion in the 90-250Hz area where the perception of absolute polarity and phase distortion is strong.

So, this could explain why you hear such a drastic difference.

With a minimum phase system you aren't gonna hear it that well. Thats kind of funny with this subject, the worst gear you got the better you will hear the phenomenon

[bob katz]

Originally Posted by bob katz

Yup, you could, but there was no standard that "north" is "plus" and "south" is "minus" for example, so you had a 50-50 chance as far as the rest of the world is concerned.

BK

Speaking of which, I understand that Ampex and Studer were always opposite! I did run some polarity test signals once on Ampices (I always wanted to plural the word "ampex") and Studers and found they were opposite. As long as you're in the world of coils, magnetic tape domains and LP cartridges and cutting, those elements of the system were never standardized. But as DC said, we could verify the polarity of the entire rest of the chain and those of us who were responsible engineers did do that. It's just certain points of origin (e.g. the magnetic tape recorder polarity, and destination (e.g. the LP cartridge polarity) that were 50-50.

So as another poster pointed out, it's far more likely than 50-50 today that absolute polarity is maintained all the way from the microphone through to the consumer's loudspeaker. Probably much better than 80-20, with the variables likely being how the consumer wires up his loudspeakers. Notwithstanding all the arguments of phase shift within loudspeakers, etc., which muddies up the waters and reduces the chances of audibly hearing the phenomenon, or maybe exagerrates it, as one poster pointed out. Non-linearities and distortions in audio equipment does exagerrate the problem, and I believe some papers have been written discussing how when the non-linearities were cleaned out, then the audibility of the polarity of a polarized sawtooth wave became much more difficult to hear. But I cannot cite the source, so call this anecdotal.

So, are Duntechs and Egglestons and some other speakers more able to reveal polarity differences because of their linearities or their non-linearities? That's the point where I have to bow out and instead of speculating please let future posters cite hard statistical single-variable evidence. Or it could become like the endless argument over whether the ear is sensitive to frequencies above 20 kHz, as in when we claim to hear differences between 192 kHz and 44.1 kHz sample rates, is it the bandwidth or the filtering?

Now, doesn't that summary close up this discussion sufficiently!!!!!!!!

[Darius van H]

Originally Posted by UnderTow

Here is a kick & saw bass with a polarity reversal half way through: http://puretone.nl/Polarity.wav

Alistair

I don't know if someone mentioned this already, but the two halfs of this wav don't cancel...................so there's a difference other than polarity.

[philip]

Originally Posted by bob katz

So, are Duntechs and Egglestons and some other speakers more able to reveal polarity differences because of their linearities or their non-linearities?

seems like the egglestons have phase distortion:

Stereophile: EgglestonWorks Andra loudspeaker

[UnderTow]

Originally Posted by Darius van H

I don't know if someone mentioned this already, but the two halfs of this wav don't cancel...................so there's a difference other than polarity.

Right you are. I'll investigate what is causing this. Thanks for pointing this out Darius.

In the mean time I generated a new file. This time I copy&pasted the bounce to the end of the exported file with inverted polarity. In other words the second half is an exact, polarity inverted, copy of the first half rather than a plugin flipping the polarity halfway through during playback.

http://puretone.nl/Polarity2.wav

(As you can hear, Sonar munches the first few ms of an export killing the transient on the first kick drum).

Alistair

[WillB]

Perhaps this has been mentioned:

Use a weak 9V battery to test your system. Feed the battery output to your analog system input. Permanently connect the negative side of the battery and then touch and retouch the positive side. The woofer should move out each time the + pulse is sent to it.

Feed the battery to the input and place a scope on the output to test each device in the audio chain separately.

Multi mic pan pot recordings will/could have essentially random polarity.

[Bob Olhsson]

The first audio manufacturer to employ XLR connectors was Ampex. As what I understand was literally a case of "just pick one," they decided to wire the connectors with pin 3 as the high side of the balanced connector.

Meanwhile an international standard was developed during the late 1950s that called for pin 2 of any electrical connector to be the high side. At the time most manufacturers outside the U.S. weren't using XLR connectors but when they entered the American market many wired their gear with pin 2 hot. Sony chose to be compatible with Ampex because they knew all of the big American broadcasters wired their facilities pin 3 hot and rewired anything that was shipped pin 2 hot because they weren't about to rewire everything in their company just to match an international standard.

The microphone industry was only just introducing the use of XLR connectors in the late '50s and they decided to ship their products with pin 2 positive for positive air pressure. Some U.S. studios and broadcasters simply rewired the mikes to pin 3 hot.

The result of all this in the U.S. was random polarity everywhere depending on where and how balanced connections became unbalanced. If you recorded a pin 2 hot mike with an Ampex, it played back pin 2 hot on the Ampex. If you played the tape on a Studer, the polarity flipped.

An amazing can of worms...

[clarkjohnsen]

Originally Posted by UnderTow

"All Telarc can do..." And that is all they need to have done to make Bob Katz' comment accurate. He never mentioned any voodoo or anything else. Why are you pretending he did? Talking about strawman arguments...

I'll take that as an admission of failure to understand, that Telarc cannot possibly have assured that the woofer excursion will be outwards-going on any given system. There's no "voodoo" there, sir; it's a functional impossibility.

The fact that many releases have polarity errors on them is irrelevant. Those are errors on the LPs and CDs, not in the system used to reproduce them. More straw....

Mercy! Enough with the assumptions. Systems have "errors" too. Already the problem with phono cartridges has been mentioned. Now I'll add that in my research (granted, several years ago) 2 out of 5 CD players were found to output a different polarity form the other 3. Can you tell us which is correct?

As for "errors", who's to say they are that? Only yourself! As I took pains to point out earlier, one polarity is as good as the other. Question is, how to know which is which?

Lupo posted a picture of the initial attacks of the kick drums in the wave I posted earlier. How can there be any doubt as to which is correct and which isn't?

On the picture, none whatsoever! Now transfer this into acoustic space via LP, CD or tape and tell us how there is still no doubt.

Non sequitur of monumental proportions.

You're very kind, but it ain't that grand.

Or are you just here to prove that your book isn't outdated? Did your publisher put you up to this?

No proof needed. Had you read it (you haven't, have you?...) you would understand that.

There is no fixed relationship if people don't care. If care is taken to keep the electrical polarity of the recording/mixing/mastering chain then that realtionship does exist.

Excuse me for being amused. I always am, at truisms offered in place of argument. At the risk of being boring for repeating myself, how does one (for example) keep the "electrical polarity" straight on an LP? Give us the definition please. Ditto, tape. As for CD, the situation may appear to be under control (an AES committee thinks it is), but nowhere is the electrical linked inextricably to the acoustic.

I appreciate your bafflement; you are not alone.

clark

Alistair

[clarkjohnsen]

Originally Posted by Lupo

Let me restate how I personally found that most CD's have a certain polarity.

They all do -- assuming the original recording manifests the effect.

It was after buying a new monitor converter that output pin 3 hot. Luckily, the converter have a polarity switch attached. After playing around with it for a while, it soon became obvious that most CD's sounded better with the switch in the inverting position. Made perfect sense as I RTFM and discovered that the XLR output was inverted in regard to what I expected. I phoned a friend that already had bought the converter a while before me. Turned out that he had the exact same experience when he started using it. Most CD's are produced with a correct(and therefore best sounding) polarity. Some are wrong, most aren't.

Again with the "right" and "wrong". Who's to say? Who's to say? On your system, right, yes, but elsewhere, with a different player or whatever, who knows?

And I must challenge your assumption that most CDs are correct -- not in the right or wrong sense, but that the bulk of them are any one way or the other. My ongoing research shows a 50/50 split; not only that, but many, many CDs incorporate both polarities, from cut to cut. How are those to be characterized?

To those of you who don't believe in a certain polarity: why do you think amps and speaker terminals are marked with positive and negative? The fact that some systems get this wrong does not make it right to have the polarity inverted. It's a technical error.

Now we're confusing electrical polarity and acoustic polarity, the latter being the topic here. They are not related. An amplifier can invert electrical polarity and still portray acoustic polarity perfectly, assuming compensation is made elsewhere.

As previously noted, whatever the phase shift is around the crossover point, it's very hard to imagine that it can invert a transient. Phase shift in the crossover zone wont flip the signal upside down. Please mic up your speakers and try. If you can post a clip proving your point, I'll be very impressed and duly humbled!

While I am not your addressee, I have to tell you, phase shifts in loudspeakers don't invert transients, they smear them.

clark