PRaT: "Pace Rhythm and Timing" or "PRetentious audiophile Trash"?

[Atmasphere]

Interesting.....So a system with PRaT can play a recording without PRaT and the music will not have PRaT?

Yes.

"By contrast, digital audio is a fragile medium. Sonic greatness remains elusive, digital replay often seeming to get bogged down at an earlier stage, one in which the listener's lack of involvement leads to a substitute activity. The mind remains busy, but is now cataloguing perceptual features and comparing them with previous experiences. This is an interesting abstraction, comparable in the realm of visual art with the analysis of the brush techniques of old masters. But, as Robert Harley points out in this month's "As We See It," an obsession with technical minutiae can blind one to an appreciation of the whole. That easy, rhythmic grace inherent in competent analog replay points to one of the greatest paradoxes of digital replay.

In the above quote, what is being discussed is how the music processing has moved from the Limbic system to the Cerebral Cortex.

Some personal thoughts on this:

I think that PRaT is something that cannot be grasped intellectually, only emotionally.

It is something you either hear or don't - some people need it in their replay, others don't notice it.

A system that is capable of PRat does not make everything sound PRaTish, but will allow one to hear the PRaT that exists in the music.

I remember a quotation in a Marcus Sauer article " I don't want to know WHERE they are on the stage, I want to know WHY they are on the stage"

Cheers

David

When the Limbic system is doing the work, our reaction is more emotional than intellectual. IMO/IME building a system that is founded on an understanding of how the ear/brain system works is what leads to a system that is in fact more musical. After that its simply engineering. The uphill battle is that the spec sheets that the industry has come to love do not tell the full story, and in some cases (such as THD) quite often the 'good' figures (such as ultra low THD) are actually indications of amusical performance; this being simply because the ear doesn't work the way the spec sheets would have us believe.

This is why after 50 years despite the 'good' specs on paper, we still can't look at the spec sheet and know how it sounds, so audition is still the final arbiter.

 

[andromedaaudio]

In my days in Thailand there was only one radar on the way to Pattaya that I think someone personally imported and generally the offenses were settled on the spot between the driver and the agent . Unless he became too greedy and he'd get the PRaT, "Why do you want to cause problem for your boss?"



It depends on your interpretation and can apply to other components but certainly the source is key.

david

Haha , a collegue of mine who worked in brasil once told a story that he was drinking a beer in a bar where a police officier also sat .
When the police officer ran out of money he said wait i ll be back .
Hé went on the street gave somebody a ticket got inside and ordered a drink

 

[Al M.]

When the Limbic system is doing the work, our reaction is more emotional than intellectual. IMO/IME building a system that is founded on an understanding of how the ear/brain system works is what leads to a system that is in fact more musical. After that its simply engineering. The uphill battle is that the spec sheets that the industry has come to love do not tell the full story, and in some cases (such as THD) quite often the 'good' figures (such as ultra low THD) are actually indications of amusical performance; this being simply because the ear doesn't work the way the spec sheets would have us believe.

This is why after 50 years despite the 'good' specs on paper, we still can't look at the spec sheet and know how it sounds, so audition is still the final arbiter.

No disagreements here, but I also enjoy music for its intellectual aspects. It's not that involvement of the intellect is bad, on the contrary. Yet as you appear to suggest, if the intellect steps in to compensate for lack of emotional content that's where the trouble begins.

 

[Pb Blimp]

The interesting thing is, why is analog naturally so good at this, while absolute speed variations in the medium are much greater than on digital with its picosecond jitter? I assume this must have to do something with the lockstep of signals within the entire frequency range relative to one another, even if in macro-terms the speed of the turntable (or analog tape) fluctuates. Or perhaps the problems in digital also have to do with, as John suggested in post #10, noise-shaping that fluctuates in correlation with the signal.

This is indeed the great mystery. To me, I often wonder if it's not about the actual speed of the music replication (i.e., the speed of the TT or the Digital playback) but the way the waves are stitched together. Even if a vinyl record was printed from a digital file it can have more PRaT to me than the digital playback of the same file. I have often wondered if its because the TT system itself is a mechanical device (just like a like a musical instrument) that generates a continuous (analog) signal from a continuous mechanical movement as opposed to a digital file of 1"s and 0's stitched together by a clock and processor. No matter how good clock and processor are, you still have femtosecond disturbances the brain can detect as the gatekeeper of the limbic system that in turn causes the brain to send the activity to the cortex.

Every sound in nature (that resulted in the human brain's evolution over the last 2 million plus years) was generated from a mechanical action in the physical world which vibrates air waves. Even though in digital playback the air is vibrated by a mechanical action (the speaker cone), this action comes from reconstruction of the original natural mechanical action using a clock and processor that by definition do not create a perfectly continuous wave (no matter how good the clock and processor). Does the brain somehow have the ability to discern this and send the signals that it can't figure out to the cortex where it tries to think about them logically as opposed to sending the signals to the limbic system where their processing would generate emotional pleasure?

I am of course talking out my bum here, but I have never seen a compelling explanation for these differences.

 

[Mike Lavigne]

I am trying to understand the term PRaT so that police wouldn’t arrest me when I misuse it.

So PRaT can only be used with tt? Can it be used with other equipments?

Kind regards,
Tang

and there is RTR PRaT. I think there is a relationship between transport quality, musical authority, and PRaT. what does a master recorder level RTR deck bring musically? it certainly varies from recording to recording; I find 'live' low gen master dubs are particularly 'PRaT' filled, like better direct-to-disc' pressing can be. not to say that the music is great.....but the micro-dynamic energy gradation is just better. the MSB Select II seems to pull PRaT out of Redbook 'live' recordings noticeably well. like that quality sits there dormant by degrees ready to be fully discovered.

so it's not just turntables; but turntable drive systems have such a variable influence on timing that we separate them on this issue sometimes.

 

[andromedaaudio]

If i may interrupt i think thats exactly the case with digital , paul

 

[Al M.]

This is indeed the great mystery. To me, I often wonder if it's not about the actual speed of the music replication (i.e., the speed of the TT or the Digital playback) but the way the waves are stitched together. Even if a vinyl record was printed from a digital file it can have more PRaT to me than the digital playback of the same file. I have often wondered if its because the TT system itself is a mechanical device (just like a like a musical instrument) that generates a continuous (analog) signal from a continuous mechanical movement as opposed to a digital file of 1"s and 0's stitched together by a clock and processor. No matter how good clock and processor are, you still have femtosecond disturbances the brain can detect as the gatekeeper of the limbic system that in turn causes the brain to send the activity to the cortex.

Every sound in nature (that resulted in the human brain's evolution over the last 2 million plus years) was generated from a mechanical action in the physical world which vibrates air waves. Even though in digital playback the air is vibrated by a mechanical action (the speaker cone), this action comes from reconstruction of the original natural mechanical action using a clock and processor that by definition do not create a perfectly continuous wave (no matter how good the clock and processor). Does the brain somehow have the ability to discern this and send the signals that it can't figure out to the cortex where it tries to think about them logically as opposed to sending the signals to the limbic system where their processing would generate emotional pleasure?

I am of course talking out my bum here, but I have never seen a compelling explanation for these differences.

The wave from a loudspeaker is no less continuous or discontinuous than the wave generated via the mechanical movement of the turntable. Thus, I don't think your hypothesis explains why a vinyl record that was printed from a digital file might have more PRaT than the digital playback of the same file.

 

[andromedaaudio]

The turntable/ record. Combo maybe stiches all those 0 and 1 s together in a. More natural way

 

[es347]

I view it as meaningless jargon.

..exactly

 

[Pb Blimp]

The wave from a loudspeaker is no less continuous or discontinuous than the wave generated via the mechanical movement of the turntable. Thus, I don't think your hypothesis explains why a vinyl record that was printed from a digital file might have more PRaT than the digital playback of the same file.

I agree but why does the PRaT get better in digital as the clock gets better. My Femto 33 is incredible compared to the early stuff. I am just sayin it must have something to do with the inaccuracy in the wave reconstruction in digital versus a mechanical device (TT).

 

[DaveC]

The interesting thing is, why is analog naturally so good at this, while absolute speed variations in the medium are much greater than on digital with its picosecond jitter? I assume this must have to do something with the lockstep of signals within the entire frequency range relative to one another, even if in macro-terms the speed of the turntable (or analog tape) fluctuates. Or perhaps the problems in digital also have to do with, as John suggested in post #10, noise-shaping that fluctuates in correlation with the signal.

IMO, it's stimulation of the nervous system's alert response, which is the result of digital artifacts. Analog's distortion and artifacts are much more benign, plus we've all gotten used to them over the decades... that's why many electronic music artists add fake analog coloration to the music, it covers up other issues and makes it easier to listen to. If you've heard some music with no added noise and then with some added noise you'll totally get this... the music seems much more natural sounding with noise added.

Anyways, it's the alert response that moves the brain's response to the music to a different part of the brain so it can get ready for whatever caused that noise! This nervous system response is also the cause of listening fatigue. I do not believe it is consciously recognized as such a large majority of the time.

 

[jkeny]

That is my experience as well, see earlier in the discussion.



The interesting thing is, why is analog naturally so good at this, while absolute speed variations in the medium are much greater than on digital with its picosecond jitter? I assume this must have to do something with the lockstep of signals within the entire frequency range relative to one another, even if in macro-terms the speed of the turntable (or analog tape) fluctuates. Or perhaps the problems in digital also have to do with, as John suggested in post #10, noise-shaping that fluctuates in correlation with the signal.

Yes, sampling analogue sound into discrete amplitude values & later reconstructing those samples back to the 'same' analogue waveform although based on sound mathematical principles, is fraught with difficulties - a major one being the reliance on timing

We often see the argument made that the timing of TTs/tape is orders of magnitude worse than digital & jitter dismissed, as a result

I have argued in the past that digital jitter is fundamentally different to TT speed fluctuations. It's obvious that the due to the physical nature of turntable rotation, speed will change in a ramping way i.e speeding up & then slowing down or vice versa in a finite time period - it's not instantly fast one instant & then slow another.

Jitter from clocks can be of many forms - two main categories being random & correlated.These categories define the statistical nature of the jitter over time. If you zoom into how clock jitter operates from moment to moment, it can be fast on one clock tick & slow on the next.e it's speed is not ramping up to fast or down to slow - there's no collection of clock ticks that are incrementally getting faster & then ramping back down to normal.

One has to then try to translate this into how we perceive these differences through our senses - not an easy task as it's mostly untrodden ground & requires an understanding of the technology & of the theories/research into auditory perception. Do we perceive a ramping up/down of speed as pitch instability? Do we perceive more random, moment to moment speed changes as indistinctness, lack of clarity, lack of PRAT?

My focus on fluctuating noise results in a similar issue to jitter - if the start of a sound is somewhat indistinct due to an increase in signal processing noise then we lose the clarity of where a sound starts which is equivalent to the effects of jitter. In modern digital equipment, although jitter can be shown to be low when measured using non-dynamic signals, this doesn't give us the full picture

 

[DaveC]

The wave from a loudspeaker is no less continuous or discontinuous than the wave generated via the mechanical movement of the turntable. Thus, I don't think your hypothesis explains why a vinyl record that was printed from a digital file might have more PRaT than the digital playback of the same file.

It will because analog distortions and noise will cover up some of the digital artifacts.

I think the alert response I mentioned is a result of evolution and the fight or flight response, for example the sound of a breaking branch as you walk through the woods...

 

[Atmasphere]

This is indeed the great mystery. To me, I often wonder if it's not about the actual speed of the music replication (i.e., the speed of the TT or the Digital playback) but the way the waves are stitched together. Even if a vinyl record was printed from a digital file it can have more PRaT to me than the digital playback of the same file. I have often wondered if its because the TT system itself is a mechanical device (just like a like a musical instrument) that generates a continuous (analog) signal from a continuous mechanical movement as opposed to a digital file of 1"s and 0's stitched together by a clock and processor. No matter how good clock and processor are, you still have femtosecond disturbances the brain can detect as the gatekeeper of the limbic system that in turn causes the brain to send the activity to the cortex.

Every sound in nature (that resulted in the human brain's evolution over the last 2 million plus years) was generated from a mechanical action in the physical world which vibrates air waves. Even though in digital playback the air is vibrated by a mechanical action (the speaker cone), this action comes from reconstruction of the original natural mechanical action using a clock and processor that by definition do not create a perfectly continuous wave (no matter how good the clock and processor). Does the brain somehow have the ability to discern this and send the signals that it can't figure out to the cortex where it tries to think about them logically as opposed to sending the signals to the limbic system where their processing would generate emotional pleasure?

I am of course talking out my bum here, but I have never seen a compelling explanation for these differences.

I've got one. When recording, in digital there is this thing called 'aliasing'. In the analog world, its a form of IMD called 'inharmonic distortion' as the distortion components are related to the scan frequency rather than fundamentals in the music.

The human ear/brain system translates this distortion (since that is what it is) into a tonality- like it does with all distortions. It hits a tipping point in the brain where the music processing is handled by the cerebral cortex.

Get rid of the aliasing (a lot of which is on the record side) and the resulting sound will be smoother and not so brittle bright. The brain is happier. There's been a lot of progress in this direction- it needs to keep coming.

 

[Pb Blimp]

I've got one. When recording, in digital there is this thing called 'aliasing'. In the analog world, its a form of IMD called 'inharmonic distortion' as the distortion components are related to the scan frequency rather than fundamentals in the music.

The human ear/brain system translates this distortion (since that is what it is) into a tonality- like it does with all distortions. It hits a tipping point in the brain where the music processing is handled by the cerebral cortex.

Get rid of the aliasing (a lot of which is on the record side) and the resulting sound will be smoother and not so brittle bright. The brain is happier. There's been a lot of progress in this direction- it needs to keep coming.

This makes sense to me. Do you believe the negative effects of aliasing are improved by better clock rate? As said, I feel clock progression and PRaT improvement have closely correlated over the years.

 

[jkeny]

Interesting. Are you saying that the problem is pervasive even in modern digital? I thought the problem was pervasive in the past, but that it has become much less over time, to the point that, with the best digital sources, there is now no problem at all.


(I am talking about uncompressed digital audio; compressed files, for example on Youtube, can sometimes sound rhythmically horrible.)

Yes, I'm saying that our tests are not revealing what our ears are telling us & a lot of it, IMO, has to do with how digital audio is handling dynamic signals, whether the reference voltage fluctuates i.e does the ground noise change with signal processing

You can see on many. many DAc datasheets that the noise floor changes with amplitude. This is ignored because it's considered that the noise floor is low enough to be inaudible. But this assumption leaves out some aspects which may be important - when handling dynamic, overlaid frequencies at different amplitudes what is the noise floor behaviour in this scenario - is it additive - ie.e the same as testing with (30 - 40) multitone signals shows an additive change in the noise floor much higher than the IMD test using 19KHz + 20KHz tones.

The second aspect to consider is just how sensitive are we to a fluctuating noise floor? We know that our auditory processing can actually ignore a fairly high level noise floor once it is fixed in amplitude - hence vinyl & analogue playback has been so successful but what about fluctuating noise floors? We need to delve into auditory processing for some understanding of this. Our auditory processing systems are continually analysing the signals being delivered on the auditory nerve. At a high level we form foreground & background auditory planes similar to the way we do the same in visual perception. So the room noise/reverberations is the background container in which the music is being played. Our auditory models of the real acoustic world don't expect this auditory background plane to change so noise fluctuations subconsciously warn us that something about the room has changed. How this effects us at various levels can be discussed

 

[Al M.]

My focus on fluctuating noise results in a similar issue to jitter - if the start of a sound is somewhat indistinct due to an increase in signal processing noise then we lose the clarity of where a sound starts which is equivalent to the effects of jitter. In modern digital equipment, although jitter can be shown to be low when measured using non-dynamic signals, this doesn't give us the full picture

Which is also why a DAC with a nominally better clock (jitter in the femtosecond range) does not necessarily sound better. The real jitter on dynamic signals may be much higher, and it also depends where exactly the clock is located relative to the DAC chip, which actual DAC architecture is implemented etc. I find the chase by some for just the jitter specification curious. I still remember the whole hoopla around the Auralic Vega a few years ago, as if the femto clock was all that mattered.

On the other hand, for a given DAC architecture a nominally better clock will probably also give better results -- such as when you go to better clocks within the MSB range of offerings.

 

[jkeny]

One thing to note, digital audio recording do not seem to suffer from issues that we are discussing - the problems seem to be in the playback stage.
We can playback old digital recordings on a good digital audio system & experience the full PRAT & liveness of the recording

 

[microstrip]

One thing to note, digital audio recording do not seem to suffer from issues that we are discussing - the problems seem to be in the playback stage.
We can playback old digital recordings on a good digital audio system & experience the full PRAT & liveness of the recording

I have tried to introduce this subject to debate more than once, but was quickly forgotten. All digital data has intrinsic jitter, most of the time of much higher magnitude than our current DACs. However no one speaks about it.

 

[jkeny]

Which is also why a DAC with a nominally better clock (jitter in the femtosecond range) does not necessarily sound better. The real jitter on dynamic signals may be much higher, and it also depends where exactly the clock is located relative to the DAC chip, which actual DAC architecture is implemented etc. I find the chase by some for just the jitter specification curious. I still remember the whole hoopla around the Auralic Vega a few years ago, as if the femto clock was all that mattered.

On the other hand, for a given DAC architecture a nominally better clock will probably also give better results -- such as when you go to better clocks within the MSB range of offerings.

Right, often the change an outboard clock makes to the sound is because it is suffering from less ground noise due to having its own PS or having better immunity in its circuitry to PS fluctuations.

I also agree - I have found that a better clock used in exactly the same place on my DACs slightly improved the sound. By better, I mean a clock with lower close-in phase noise which is usually not a particularly low value in standard clocks & often isn't measured for the datasheet