I think this statement is based on a misunderstanding.
The mains polarity doesn't have an influence on the signal polarity.
But it does in fact have an influence on the signal quality since not both leads of a mains transformer have the same (parasitic) coupling capacitance against the secondary side (there are exceptions of course or even some with a screen !). And this coupling capacity is a path for hash going into your equipment.
Regards
Charles
phase_accurate said:
Let's see if you get my MESSAGE better.
With message I do not mean ripping one line out of context
and so twist what a person is trying to say.
Of course I could do this too.
Especially with persons I have less respect for.
But prefer to try to read persons right.
Because they are trying to get some message through to me
So here is my main message again:
Regards
lineup
and good luck with your readingIt strikes me that the absolute polarity doesn't really matter in most recordings because they are multi-tracked. Even if the absolute polarity is preserved for each microphone / track, the relative phase of each will be different when mixed down to stereo compared with if you were to stand in the room at a single spot and listen live. As such, I don't see how absolute polarity can matter much at all in comparison to the relative phase of the different instruments in the recording. Recordings done with just a stereo mic and asymmetric waveforms being the exception, but how common are they? I don’t have many in my collection.
With periodic waveforms it seems impossible that absolute polarity can be audible except maybe for the first half of the very first cycle of the waveform.
Just my 2p.
With periodic waveforms it seems impossible that absolute polarity can be audible except maybe for the first half of the very first cycle of the waveform.
Just my 2p.
Hi SY,
)
Hi Tenson,
Those are the points I've been trying to make. Even if you get the kick drum in phase, the piano might be out. I'd say that people get too worried about some things.
-Chris
That would imply a DC component. Gone with the first coupling cap (assuming a non-acoustic source or absence of steady wind
)Hi Tenson,
Those are the points I've been trying to make. Even if you get the kick drum in phase, the piano might be out. I'd say that people get too worried about some things.
-Chris
No, not necessarily. As long as the integral of the positive half equals the integral of the negative half, there's no DC component. This will happen automatically to any signal when the DC component is removed, but most asymmetric signals will remain asymmetric.
This is why pedantic a-holes like me insist on differentiating "phase" and "polarity." There's likely to be a phase difference. There is unlikely to be a polarity difference.
To lineup:
Sorry if I caused confusion. I did not mean to imply that YOU were thinking that the polarity inversion of a mains plug has influence on the audio signal's polarity. But I assume that georegluis is thinking just that.
But I stand by my opinion that the polarity of the mains plug has influence on the coupling of unwanted signals from the mains into an audio device and thereby possibly degrading the audio quality.
Regards
Charles
Sorry if I caused confusion. I did not mean to imply that YOU were thinking that the polarity inversion of a mains plug has influence on the audio signal's polarity. But I assume that georegluis is thinking just that.
But I stand by my opinion that the polarity of the mains plug has influence on the coupling of unwanted signals from the mains into an audio device and thereby possibly degrading the audio quality.
Regards
Charles
phase_accurate said:
There is no indication that correct absolute polarity sounds better or provides better 'quality'. Only that in some cases it is detectable as a difference.
Since it is mainly asymmetric waveforms that show up the difference, then even on CDs recorded with a stereo mic only, it would only be when an instrument with asymmetric waveform is playing - and then it would only sound 'different' not worse or better.
I'm all for correct relative phase between the instruments in a recording (easy with a stereo mic), but absolute polarity? Hmmm.... doesn't matter for my music collection.
Consider that a shelf EQ used on many classical recordings to boost the low end will alter the phase response of each instruments spectrum. Now, even with an asymmetric waveform, neither polarity will give you the same phase response the instrument had in the original performance… so neither is ‘correct’.
Like you say though, one may as well make sure that there own system at least, is reproducing the correct polarity, even if we can't control the recording process.
Tenson said:
Just today I let a hifi store owner do a test, and different speakers yielded different magnitude of differences. Generally, the cleaner the speakers sounded, the more obvious the preference. He was surprised at this result, and asked why it is so, my simple explanation was that different speakers have different diaphram vribration modes that mask these differences. Just my 2 cents worth.
Playing around with a CD player with remote switchable phase proved quite interesting to me. It was often possible to hear differences, but identifying the 'correct' polarity was more difficult, particularly with more complex music. As others have suggested, there is probably not a correct polarity for much studio music with multiple mics and processing. Most often I would choose the option where the drums sounded right and had the best impact.
The most amazing difference was on a Paco Pena solo guitar piece, where switching polarity actually changed the tonality of the guitar. I could liken it to the difference between strumming up or strumming down. I guess the greatest benefit of getting the absolute phase correct is with instuments with lots of leading edge information and simply mic'd recordings.
The most amazing difference was on a Paco Pena solo guitar piece, where switching polarity actually changed the tonality of the guitar. I could liken it to the difference between strumming up or strumming down. I guess the greatest benefit of getting the absolute phase correct is with instuments with lots of leading edge information and simply mic'd recordings.
float said:
In some CDs you might find different polarity preferences for different instruments.
I actually raised the question in a mic builder's group, it seems many are not aware that it makes a difference. Some mentioned there is a requirement that positive pressure should result in positive voltage at pin 2 of a mic connector, not all makers follow that rule. Some say that using a figure 8 pattern mic, there is no indication which side is polarity inverted, they only know that one side is inverted and the other not. Many have indicated they wanted to figure out a way verify before recording though, and some already do. So that's a good sign.
Which is going back to reletive phase again...
Phase is not just an issue of the mic remeber, it is alterd by any EQ and the signal goes through lots of other equiipment which may or may not invert the phase. It would be a bit of a job for the engineer to keep track of every signal and check its polarity. You have to remeber that a lot of the best engineers are freelance and do not always work in the same studio they are familiar with. And I repeat, one polarity is not always better than the other, just different so it will be down to perference in the end as well. What I mean is that if the engineer wants it to sound 'nicer' he has many more powerful tools at his fingertips than playing with polarity - so why would he bother?
As before, just my 2p!
Phase is not just an issue of the mic remeber, it is alterd by any EQ and the signal goes through lots of other equiipment which may or may not invert the phase. It would be a bit of a job for the engineer to keep track of every signal and check its polarity. You have to remeber that a lot of the best engineers are freelance and do not always work in the same studio they are familiar with. And I repeat, one polarity is not always better than the other, just different so it will be down to perference in the end as well. What I mean is that if the engineer wants it to sound 'nicer' he has many more powerful tools at his fingertips than playing with polarity - so why would he bother?
As before, just my 2p!
SY said:
Hi SY. What did you have in mind? These days it's no certainty musicians on popular releases were ever in the same city simultaneously, much less the same studio. Phase scramblers ('de-asymmetrifiers') are common issue on mic processors. And horror piled on horrors, big name FM broadcast processor manufacturers are selling 7-band sonic meat grinders for mastering use. The odds of any but specialized releases having a sum polarity marginally related to the original sonic event(s) are safely in the range of catching a ride on Hale-Bopp's next pass.
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