PHASED.
Hi,
Well even if one doesn't have a clue of the circuit topology inside the same trick with the battery on the input and the woofer on the output should still reveal wheter that piece of gear respects absolute phase or not.
The engineers of the sixties usually developped their stuff so that every unit did respect absolute phase.
A lost practice, Im afraid.
Cheers,
Hi,
Well even if one doesn't have a clue of the circuit topology inside the same trick with the battery on the input and the woofer on the output should still reveal wheter that piece of gear respects absolute phase or not.
The engineers of the sixties usually developped their stuff so that every unit did respect absolute phase.
A lost practice, Im afraid.
Cheers,
Absoloute Is Absoloute
Ok, somebody correct me if they think I am wrong here.
By Correct Absoloute Polarity, I mean that the loudspeaker reproduces a pressure pulse presented to a microphone, regardless of all the stages in between the original microphone and the final replay speaker.
For example, if a microphone is placed in front of a kick drum it transduces a positive pressure initial wavefront, and despite polarity inversions throughout the entire recording and replay signal path, the woofer of the loudspeaker is required to be wired (polarity) such that it reproduces this positive pressure initial wavefront.
If the woofer (loudspeaker system) is wired reversed, the sound
is distintly different to correct polarity, and efficiency and intelligibility declines, as does depth imaging.
Inverted sound is wrong sound, and does not occur in nature.
Phase relationships is a different thing, and refers to relative signal delays between the constituent frequencies in an audio (any) waveform.
Electronic signal filtering and crossover filters introduce delays that interfere with (alter) the phase coherency of constituent frequencies over the audio band, and this also serves to alter realism and intelligibility of the final reproduced sound.
A phase flat, correct polarity wired system is required to accurately reproduce recorded sound.
Most systems do not exhibit this behaviour, and this causes character and colouration, and whilst not completely phase linear can still be regarded as 'nice' sound, but not accurate.
Some systems sound wrong in either AP, but less wrong in one polarity, and this can be due to (mainly) crossover and driver phase behaviour.
It is also worth to note that some systems sound different according to the polarity of the signal exiting the amplifier (input normal/speaker normal = correct AP VS input inverted/speaker inverted = correct AP), and suggest amplifier system non linear behaviour related to signal polarity peak amplitudes.
Eric.
Ok, somebody correct me if they think I am wrong here.
By Correct Absoloute Polarity, I mean that the loudspeaker reproduces a pressure pulse presented to a microphone, regardless of all the stages in between the original microphone and the final replay speaker.
For example, if a microphone is placed in front of a kick drum it transduces a positive pressure initial wavefront, and despite polarity inversions throughout the entire recording and replay signal path, the woofer of the loudspeaker is required to be wired (polarity) such that it reproduces this positive pressure initial wavefront.
If the woofer (loudspeaker system) is wired reversed, the sound
is distintly different to correct polarity, and efficiency and intelligibility declines, as does depth imaging.
Inverted sound is wrong sound, and does not occur in nature.
Phase relationships is a different thing, and refers to relative signal delays between the constituent frequencies in an audio (any) waveform.
Electronic signal filtering and crossover filters introduce delays that interfere with (alter) the phase coherency of constituent frequencies over the audio band, and this also serves to alter realism and intelligibility of the final reproduced sound.
A phase flat, correct polarity wired system is required to accurately reproduce recorded sound.
Most systems do not exhibit this behaviour, and this causes character and colouration, and whilst not completely phase linear can still be regarded as 'nice' sound, but not accurate.
Some systems sound wrong in either AP, but less wrong in one polarity, and this can be due to (mainly) crossover and driver phase behaviour.
It is also worth to note that some systems sound different according to the polarity of the signal exiting the amplifier (input normal/speaker normal = correct AP VS input inverted/speaker inverted = correct AP), and suggest amplifier system non linear behaviour related to signal polarity peak amplitudes.
Eric.
AP-III CONTINUED MARK II.
Howdy Eric,
While I understand what you're saying, I feel you're making it a bit more complicated than overall necessary.
So,to recap...
Whilst you're recording a single drum being hit it will produce a forward wavefront.The skin was kicked forward.
In reproduction of the recorded sound, the woofer cone will be displaced forward.
In that case the system respects absolute phase.
In between you can have a number of inverting or non-inverting stages, it doesn't matter as long as the net result adds up to the original polarity.
Speakers that sound better wired one way or the other do not belong in hi-fi systems, they're crap from the start and unless they're redesigned no amount of fiddling is going to change that.
Cheers,
Howdy Eric,
While I understand what you're saying, I feel you're making it a bit more complicated than overall necessary.
So,to recap...
Whilst you're recording a single drum being hit it will produce a forward wavefront.The skin was kicked forward.
In reproduction of the recorded sound, the woofer cone will be displaced forward.
In that case the system respects absolute phase.
In between you can have a number of inverting or non-inverting stages, it doesn't matter as long as the net result adds up to the original polarity.
Speakers that sound better wired one way or the other do not belong in hi-fi systems, they're crap from the start and unless they're redesigned no amount of fiddling is going to change that.
Cheers,
The Wires That Polarize.
Hi Frank,
I was just trying to be precise here, sorry if seemingly too complex explanation, and thanks for your condensation of the facts.
Ummm, I find just about any speaker sounds better when wired for correct AP, and the ones (some) that sound better wired in reversed AP are junk indeed. (usually mids are wrong)
My last comment was about amplifiers, and SET amplifiers are a strong example where amplifier input signal polarity and speaker polarity need to be optimised for correct overall AP and sound.
Eric.
Hi Frank,
I was just trying to be precise here, sorry if seemingly too complex explanation, and thanks for your condensation of the facts.
Ummm, I find just about any speaker sounds better when wired for correct AP, and the ones (some) that sound better wired in reversed AP are junk indeed. (usually mids are wrong)
My last comment was about amplifiers, and SET amplifiers are a strong example where amplifier input signal polarity and speaker polarity need to be optimised for correct overall AP and sound.
Eric.
AP-IV.
Hi,
Which indicates that the midrange unit is wired the wrong way around.
Reversing the leads internally at the unit side should solve that.
Yes,and you know why that is, don't you?
I also understand why some people prefer to have an active preamp in those cases...that would set it straight again in most cases.
I explain:
Given that the SET amp deploy a sinlge driver stage that will reverse absolute phase, preceding it with a single triode stage is going to net in a correct result phasewise.
Cheers,
Hi,
Which indicates that the midrange unit is wired the wrong way around.
Reversing the leads internally at the unit side should solve that.
Yes,and you know why that is, don't you?
I also understand why some people prefer to have an active preamp in those cases...that would set it straight again in most cases.
I explain:
Given that the SET amp deploy a sinlge driver stage that will reverse absolute phase, preceding it with a single triode stage is going to net in a correct result phasewise.
Cheers,
Hi Frank,
No that is not why I mentioned SET amplifiers.
The fact that they are inverting is not what I meant.
SET amplifiers are inherently lon-linear positive half cycle VS negative half cycle - highly distorted.
The amplifier and speaker need to be wired for best behaviour, and the input signal polarity adjusted accordingly to give correct in roonm AP.
I find cd's and records (especially compilation collections) commonly have tracks recorded in pretty much random polarity,
and the ultimate cure is to flip polarity at the signal source end as required.
At work I have a transformer box for this purpose, and at home I flip polarity at the cables into the back of the loudspeakers - I don't mind, but it does grate the missus sometimes if I am up and down every second track correcting AP, but she does clearly hear the difference, and does clearly prefer correct in room AP.
Best possible would be digital inversion before the DAC stage, and then the whole signal chain is running in the one particular (sonically optimum) polarity at all times.
This could also be done with phono input pre-amp stages.
For continued optimum GFAF, I'll get around to building some IR remote controlled soloutions sometime - then everybody can be happy.
Nelson makes comment in an earlier paper about air being non linear, and that his single ended amplifier of the time to be beneficial (mimicking the single ended nature of air), but he does not make mention of speaker connection polarity or input signal polarity considerations.
Nowadays I hear AP perfectly clearly, and if the music is inverted, I find the ultimate enjoyment goes, and the music sounds just plain wrong to me.
Eric.
No that is not why I mentioned SET amplifiers.
The fact that they are inverting is not what I meant.
SET amplifiers are inherently lon-linear positive half cycle VS negative half cycle - highly distorted.
The amplifier and speaker need to be wired for best behaviour, and the input signal polarity adjusted accordingly to give correct in roonm AP.
I find cd's and records (especially compilation collections) commonly have tracks recorded in pretty much random polarity,
and the ultimate cure is to flip polarity at the signal source end as required.
At work I have a transformer box for this purpose, and at home I flip polarity at the cables into the back of the loudspeakers - I don't mind, but it does grate the missus sometimes if I am up and down every second track correcting AP, but she does clearly hear the difference, and does clearly prefer correct in room AP.
Best possible would be digital inversion before the DAC stage, and then the whole signal chain is running in the one particular (sonically optimum) polarity at all times.
This could also be done with phono input pre-amp stages.
For continued optimum GFAF, I'll get around to building some IR remote controlled soloutions sometime - then everybody can be happy.
Nelson makes comment in an earlier paper about air being non linear, and that his single ended amplifier of the time to be beneficial (mimicking the single ended nature of air), but he does not make mention of speaker connection polarity or input signal polarity considerations.
Nowadays I hear AP perfectly clearly, and if the music is inverted, I find the ultimate enjoyment goes, and the music sounds just plain wrong to me.
Eric.
THE PLOT THICKENS.
Hi,
No, distortion hasn't got anything to do with it, Eric.
You hear phase reversal more clearly because they hardly use any NFB at all.
That would be valid for any amplifier, regardless of topology.
Most modern records are a mess, I have a Counterpoint SA-Pi for that although I hardly use it anymore.
I couldn't agree more with you here.
Yes, I do that for a good, although rather selfish, reason.
I can explain if you twist my arm long enough.
Cheers,
Hi,
No, distortion hasn't got anything to do with it, Eric.
You hear phase reversal more clearly because they hardly use any NFB at all.
That would be valid for any amplifier, regardless of topology.
Most modern records are a mess, I have a Counterpoint SA-Pi for that although I hardly use it anymore.
I couldn't agree more with you here.
Yes, I do that for a good, although rather selfish, reason.
I can explain if you twist my arm long enough.
Cheers,
Harmony ......
Howdy Frank,
I'm finally back home - it's now 2 am and the day is nearly closed -a happy day.
Today was the 9-6 thing, then onto to a friend's place and doing some studio recording stuff, and then onto seeing an Australian maestro legend muso friend for more interesting A/B's, recordings and stuff.
Ever heard a National Steel guitar played in the flesh in a loungeroom by a master - plugged and unplugged ? - Dang, those things are loud on their own, and then they plug them into amplifiers !.
Anyway, SE amps are predominately 2nd harmonic, and even order in character, or something - say so if this is wrong.
I think I read somewhere that because speaker drivers are velocity dependant or something, that if fed wrong polarity will effectively emphasize 2nd harmonic distortion or something.
Another point is that dynamic speaker drivers switch function to being generators in overshoot conditions (moving mass stored energy), and that it is to be reasonably expected (especially SET) that drive and damping behaviours are different according to the polarity of the dynamic load (reactive load).
IOW - normal polarity source >inverting SET>inverted polarity loudspeaker, ought to sound different to Inverted polarity source>inverting SET> normal polarity loudspeaker, due to dynamic drive and damping characteristics being different in the SET amplifier stage.
This causes fundamentally differing overall distortion characteristics, and is evident upon carefull listening in all amplifiers that I have thus tested for this so far.
Eric / - Never Thought You Had A Selfish Bone In You.
Howdy Frank,
I'm finally back home - it's now 2 am and the day is nearly closed -a happy day.
Today was the 9-6 thing, then onto to a friend's place and doing some studio recording stuff, and then onto seeing an Australian maestro legend muso friend for more interesting A/B's, recordings and stuff.
Ever heard a National Steel guitar played in the flesh in a loungeroom by a master - plugged and unplugged ? - Dang, those things are loud on their own, and then they plug them into amplifiers !.
Anyway, SE amps are predominately 2nd harmonic, and even order in character, or something - say so if this is wrong.
I think I read somewhere that because speaker drivers are velocity dependant or something, that if fed wrong polarity will effectively emphasize 2nd harmonic distortion or something.
Another point is that dynamic speaker drivers switch function to being generators in overshoot conditions (moving mass stored energy), and that it is to be reasonably expected (especially SET) that drive and damping behaviours are different according to the polarity of the dynamic load (reactive load).
IOW - normal polarity source >inverting SET>inverted polarity loudspeaker, ought to sound different to Inverted polarity source>inverting SET> normal polarity loudspeaker, due to dynamic drive and damping characteristics being different in the SET amplifier stage.
This causes fundamentally differing overall distortion characteristics, and is evident upon carefull listening in all amplifiers that I have thus tested for this so far.
Ok, I am twisting your arm......
Eric / - Never Thought You Had A Selfish Bone In You.
AP-V
Hi,
Predominantly even order distortion, i.e. 2nd 4th etc.
I sincerely doubt that.
None of the above have anything to do with phase IMO.
Phase lag, is a kind of distorsion but has no bearing on harmonic distortion though.
- - = + > end result = source.
This is the same as + + = +.
Both should sound exactly the same.
No, the net result is again in phase.
- + = - > end result = source.
If you can measure this I'll buy you a case of lager.
Ouchhh...
O.K. So here goes; in order to make life easier on myself and the people I explain this stuff to I distinguish between polarity and phase in the context of showing phase reversal.
For example I would say I reverse the polarity of the speaker cable (reversing the red for the black colourcoded lead) on one end to show that by doing so I reverse absolute phase of the speaker, it has now gone through a 180 degree turn, the speaker is now pulling as opposed to pushing with respect to a positive pulse.
To simplify: anything colourcoded or with a + or - sign on it, I refer to with the term polarity: batteries (have no phase but have polarity), mains leads are colourcoded and have both polarity and phase : they pulsate at 50 to 60 Hz intervals on both colourcoded wires.
Can you stop twisting my arm now?
Cheers,
Hi,
Predominantly even order distortion, i.e. 2nd 4th etc.
I sincerely doubt that.
None of the above have anything to do with phase IMO.
Phase lag, is a kind of distorsion but has no bearing on harmonic distortion though.
- - = + > end result = source.
This is the same as + + = +.
Both should sound exactly the same.
No, the net result is again in phase.
- + = - > end result = source.
If you can measure this I'll buy you a case of lager.
Ouchhh...
O.K. So here goes; in order to make life easier on myself and the people I explain this stuff to I distinguish between polarity and phase in the context of showing phase reversal.
For example I would say I reverse the polarity of the speaker cable (reversing the red for the black colourcoded lead) on one end to show that by doing so I reverse absolute phase of the speaker, it has now gone through a 180 degree turn, the speaker is now pulling as opposed to pushing with respect to a positive pulse.
To simplify: anything colourcoded or with a + or - sign on it, I refer to with the term polarity: batteries (have no phase but have polarity), mains leads are colourcoded and have both polarity and phase : they pulsate at 50 to 60 Hz intervals on both colourcoded wires.
Can you stop twisting my arm now?
Cheers,
Re: AP-V
But that rather presupposes that the people you explain this stuff to have no interest in actually learning anything. What is learned when a specific phenomenon is described using erroneous terminology?
Phase and polarity describe two completely different phenomena. You wouldn't go around using the term voltage to describe current would you?
But the speaker hasn't gone through any degree turn. All you've done is change the reference point. There is no change of phase. How is this erroneous explanation any simpler or easier to understand than the proper explanation?
Sorry, but I don't get the rationale here at all.
se
fdegrove said:
But that rather presupposes that the people you explain this stuff to have no interest in actually learning anything. What is learned when a specific phenomenon is described using erroneous terminology?
Phase and polarity describe two completely different phenomena. You wouldn't go around using the term voltage to describe current would you?
But the speaker hasn't gone through any degree turn. All you've done is change the reference point. There is no change of phase. How is this erroneous explanation any simpler or easier to understand than the proper explanation?
Sorry, but I don't get the rationale here at all.
se
Hi all
This is an interesting article on just that point.
http://usuarios.uninet.com.br/~edelima/REASONS.htm
Maybe you are hearing something besides absolute polarity when you switch.
CRyder
This is an interesting article on just that point.
http://usuarios.uninet.com.br/~edelima/REASONS.htm
Maybe you are hearing something besides absolute polarity when you switch.
CRyder
SEMANTICS ?
Hi,
Which is precisely why I distinguish between the two.
In the context of phase reversal it shows that, for instance when I reverse the polarity of the speaker leads at one end, the absolute phase of the speaker wil be reversed with respect to source.
I am by no means talking nonsense here I would think?
Cheers,
Hi,
Which is precisely why I distinguish between the two.
In the context of phase reversal it shows that, for instance when I reverse the polarity of the speaker leads at one end, the absolute phase of the speaker wil be reversed with respect to source.
I am by no means talking nonsense here I would think?
Cheers,
Polarity, Now Write It 100 Times....
Hi Frank,
I think you are not quite understanding my point here.
What I mean is that for the same in room AP, a slightly different sound character is caused according to the signal polarity through the electronics stages.
This is fully to be expected with an SE type amplifier, and fully expected not to be with a PP type amplifier.
The truth as I have heard it by experiment is that PP amplifiers are still slightly polarity of load dependent, and although the difference is slight it is audible.
Sine wave testing likely will not pick this up, but impulse/spectral testing ought to I think.
Twisting your arm...... I should be kicking your butt also for using incorrect terms I reckon, and whilst I am enjoying your beer.
Polarity is polarity, and the audio signal passing through the electronics can be described as positive going, or negative going.
Phase refers to time shifting WRT a particular reference, and is very much NOT the same thing.
Your butt is going to be so sore that you won't be able to sit down for a week by the time we have finished with you.
Your explanations I find to be confusing here, and would confuse the novice too, because of usage wrong terms.
The above would more correctly read "......when I reverse the polarity of the speaker leads at one end, the ACOUSTIC POLARITY in the room wil be reversed.
Be careful lest I come over and drink that beer you mention.
Eric / - not fashion or phase concious, polarity concious, yes.
Hi Frank,
I think you are not quite understanding my point here.
What I mean is that for the same in room AP, a slightly different sound character is caused according to the signal polarity through the electronics stages.
This is fully to be expected with an SE type amplifier, and fully expected not to be with a PP type amplifier.
The truth as I have heard it by experiment is that PP amplifiers are still slightly polarity of load dependent, and although the difference is slight it is audible.
Sine wave testing likely will not pick this up, but impulse/spectral testing ought to I think.
Twisting your arm...... I should be kicking your butt also for using incorrect terms I reckon, and whilst I am enjoying your beer.
Polarity is polarity, and the audio signal passing through the electronics can be described as positive going, or negative going.
Phase refers to time shifting WRT a particular reference, and is very much NOT the same thing.
Your butt is going to be so sore that you won't be able to sit down for a week by the time we have finished with you.
Your explanations I find to be confusing here, and would confuse the novice too, because of usage wrong terms.
The above would more correctly read "......when I reverse the polarity of the speaker leads at one end, the ACOUSTIC POLARITY in the room wil be reversed.
Be careful lest I come over and drink that beer you mention.
Eric / - not fashion or phase concious, polarity concious, yes.
WRONG.
Hi,
This not at all what I was thought.
Seems I guessed correctly when I labelled a previous post "semantics".
While I understand what you mean and what you're concerned about the naming of it doesn't sit right with me.
To ring a little bell with you : your entire concern would be irrelevant in a balanced system, right?
Cheers,
\next case is on Michael Elliot of Counterpoint....no better still, I'll explain positive and negative halves of a wave: +180 - 180- degrees in the sun.
Hi,
This not at all what I was thought.
Seems I guessed correctly when I labelled a previous post "semantics".
While I understand what you mean and what you're concerned about the naming of it doesn't sit right with me.
To ring a little bell with you : your entire concern would be irrelevant in a balanced system, right?
Cheers,
\next case is on Michael Elliot of Counterpoint....no better still, I'll explain positive and negative halves of a wave: +180 - 180- degrees in the sun.
Re: SEMANTICS ?
With all due respect (and ya know I love ya, man! ), that is nonsense. If nonsense means factually incorrect.
As I said previously, phase is a <b>time domain</b> phenomenon. When you change the polarity of the speaker cables, you change nothing in the time domain, not even at the speaker. No change in the time domain, no change in phase. Only a change of polarity.
Sure, if you look at a graph of two sinewaves where one sinewave has been delayed such that there's a 180 degree phase shift between one and the other, it will LOOK the same as a graph of two sinewaves in which there is no delay but one has simply had its polarity reversed.
And perhaps this is why you don't have a problem using the word "phase" to describe "polarity."
However plot the same graph using two asymmetrical waveforms instead of simple symmetrical sinewaves, and now the two plots won't look the same. And that's because phase and polarity are not one and the same.
se
fdegrove said:
With all due respect (and ya know I love ya, man!
), that is nonsense. If nonsense means factually incorrect.As I said previously, phase is a <b>time domain</b> phenomenon. When you change the polarity of the speaker cables, you change nothing in the time domain, not even at the speaker. No change in the time domain, no change in phase. Only a change of polarity.
Sure, if you look at a graph of two sinewaves where one sinewave has been delayed such that there's a 180 degree phase shift between one and the other, it will LOOK the same as a graph of two sinewaves in which there is no delay but one has simply had its polarity reversed.
And perhaps this is why you don't have a problem using the word "phase" to describe "polarity."
However plot the same graph using two asymmetrical waveforms instead of simple symmetrical sinewaves, and now the two plots won't look the same. And that's because phase and polarity are not one and the same.
se
Polarised But Still Not Phased
Nope, WRONG still.
In a balanced system there are two signal lines and yes they are commonly referred to as +ve phase, and -ve phase lines, but this is wrong terminology too.
I have also heard them referred to as normal or non-inverted signal, and inverted signal.
Swapping the connections of these two wires will cause signal polarity inversion, but no time shifting.
Steve gives a good explanation here too - thanks Steve.
Maybe Steve and I need to come around and beat this into you while we share your beer.
Cheers, Eric.
Nope, WRONG still.
In a balanced system there are two signal lines and yes they are commonly referred to as +ve phase, and -ve phase lines, but this is wrong terminology too.
I have also heard them referred to as normal or non-inverted signal, and inverted signal.
Swapping the connections of these two wires will cause signal polarity inversion, but no time shifting.
Steve gives a good explanation here too - thanks Steve.
Maybe Steve and I need to come around and beat this into you while we share your beer.
Cheers, Eric.
Re: Polarised But Still Not Phased
Shouldn't that be "Beeeaaah"? That's how they say it in the commercials.
"Fosters. Australian for beeeaaah."
se
mrfeedback said:Steve gives a good explanation here too - thanks Steve.
Maybe Steve and I need to come around and beat this into you while we share your beer.
Shouldn't that be "Beeeaaah"? That's how they say it in the commercials.
"Fosters. Australian for beeeaaah."
se
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