Pace, rhythm and timing. What do these terms mean to you with respect to hifi?

[Sue Pertwee-Tyr]

This made me laugh out loud and is a lovely illustration of a point Jim was making earlier. The frequency response is the transfer function which maps the input signal onto the output signal. It contains everything about when the highest and lowest octaves are delivered. For illustration, if you take the inverse FFT of the frequency response of a recorded song then you will get that song in the time domain. Note for note with no errors in pace, rhythm or timing (dictionary meaning of the words) only the usual errors associated with discretizing a signal. All the information in a song is in it's frequency response.

(For completeness I should point out that nonlinearities are not part of a linear transfer function.)

So, in not explaining this @mansr either didn't know, or knew but chose not to say it, having therefore set a little passive-aggressive trap which he, no doubt, has chuckled along to with you. You see, for me, a FR graph is that thing of frequency vs amplitude that is plotted for loudspeakers. Had he taken the slightest of moments to explain or correct my misunderstanding, the joke at my expense would clearly have failed.

But in any event, if the FFT of the frequency response is the time domain, then as we know no system (esp loudspeakers) completely accurately reproduces the frequency response, then it follows that there are consequent time domain errors. Which makes me wonder why mansr would say, upthread, that he is unconvinced there are timing anomalies.

Perhaps what he means is that there are no timing anomalies which are not in themselves also frequency anomalies. But if that's what he meant, he tried quite hard not to say it. I can only surmise why, and that makes him a troll.

 

[mansr]

Group delay?

Not to any relevant extent. To alter the relative timing of notes played by any audible amount would require a ridiculous phase response. No actual sound reproduction system comes anywhere close.

 

[mansr]

As I've already said, I suspect what some people mean by PRAT is emphasis (or lack thereof) in the "thump" region of the frequency spectrum. While having nothing to do with timing, a boost there will make music sound more rhythmic even though the actual rhythm is unchanged.

 

[tpetsch]

It's always amazed me how systems comprised of mixed components can work properly to accurately recreate an artists intended performance on playback. ...Think about it, in some cases systems comprised of a dozen different components all made by different manufacturers, all with their own ideas on the "end result". Begin by choosing some TT and a cartridge by a different manufacturer, then different amps/pre-amps, different speakers / x-overs, several different interconnect cables & different types of environments the system is set up in and you begin to wonder how can any of it can make accurate music reproduction, and if it somehow does did was it just by luck? The possibilities are enough to make a mathematician break out his slide rule ...So when I consider all of this, I think of course one systems can sound more "In-Tune" or musically accurate than another.

 

[sideshowbob]

As I've already said, I suspect what some people mean by PRAT is emphasis (or lack thereof) in the "thump" region of the frequency spectrum. While having nothing to do with timing, a boost there will make music sound more rhythmic even though the actual rhythm is unchanged.

Having heard systems which supposedly major on PR&T I think this is spot on

 

[say it as it is]

Not getting dragged into the debate but let's be honest some setup sound different to others. Do they change the music of course not a recording is just that. But humans being the simple creatures we are can only take so much in at any given time. Hence the perception if sounds are separated, eg timed different we can hear it. Can't argue that tight bass starts and stops quicker or appears that way at least as doesn't bloom or continue being audible.

 

[h.g.]

I think that he was talking about a frequency response plot/curve and you are referring to a frequency response measurement.

I think you might have to expand on that for those of us that consider frequency response to be a technical term with an unambiguous meaning. Not saying it can't be done just that I can't see the difference.

Had he taken the slightest of moments to explain or correct my misunderstanding, the joke at my expense would clearly have failed.

I didn't laugh at you as a person but at "subjective" audiophiles as a group that don't stick to the subjective and have no interest in the science of sound and home audio instead preferring audiophile marketing like PRAT. If Jim hadn't posted earlier it would have likely washed over me like it normally does.

If you want zero time domain errors it is straightforward to achieve (on axis) for a loudspeaker using DSP. There is however no technical reason to do it because the gentle changes of phase with frequency in typical loudspeakers are well below what would be required to be audible. Like always there are audiophile enthusiasts/nutjobs claiming otherwise but it is a straightforward experiment to perform if you want to check rather than follow the results of earlier work. There is a potential benefit in being "perfect" and able to show plots of square waves in the marketing bumpf but unfortunately there is also a downside in that it can introduce off-axis pre-ringing for multi-driver speakers. Not sure of the practical audibility of the latter in a well sorted system but it does seem to have largely stopped the main commercial studio speaker manufacturers bringing out examples with the odd exception like the K&H 0500 from 15 years ago which didn't seem to be particularly successful.

 

[tuga]

Not to any relevant extent. To alter the relative timing of notes played by any audible amount would require a ridiculous phase response. No actual sound reproduction system comes anywhere close.

Perhaps yes, perhaps no. https://www.kvalsvoll.com/blog/2019/08/20/audibility-of-group-delay-at-low-frequencies/

 

[Sue Pertwee-Tyr]

I didn't laugh at you as a person but at "subjective" audiophiles as a group that don't stick to the subjective and have no interest in the science of sound and home audio instead preferring audiophile marketing like PRAT. If Jim hadn't posted earlier it would have likely washed over me like it normally does.

Well, thank you for the clarification .

But you'll know that subjective audiophiles are not allowed to stick to the subjective - the demands of the objective crowd require technical explanation and the subjective side is invariably goaded into repeating the explanations offered, or giving their own hypothesis. So it's a case of damned if we do, and damned if we don't.

Look at this thread. It's clearly not a troll thread like some cable ones are (the OP's reputation clearly makes that a non-starter). The question is 'what do you understand by the term PRaT'. For which, any answer where the respondent sets out their understanding is a perfectly proper and reasonable response to the thread. And we could have a civil discussion about how valid or relevant those understandings are. But we never do, do we? Why is that, would you say?

 

[mansr]

Perhaps yes, perhaps no. https://www.kvalsvoll.com/blog/2019/08/20/audibility-of-group-delay-at-low-frequencies/

Firstly, those are extreme cases, created artificially. Secondly, even if the difference is audible, it won't be as a change in rhythm or timing.

 

[tuga]

Firstly, those are extreme cases, created artificially. Secondly, even if the difference is audible, it won't be as a change in rhythm or timing.

I don't really know how PRaT manifests itself audibly so I can't really say. But you were the one who brought up timing differences.

 

[DimitryZ]

Not to any relevant extent. To alter the relative timing of notes played by any audible amount would require a ridiculous phase response. No actual sound reproduction system comes anywhere close.

And that's why some spend serious time adjusting the location and phase of their subwoofers.

 

[Nic Robinson]

Great thread. I'm somewhat gratified that my inability to understand the phrase's meaning is shared by many. I hope few will think that my willingness to state it destroys my already meagre hifi credentials, or that I am, indeed, "colour blind" in an audio sense. I do admit to being able to enjoy wonderful music on any system including poor car radios and old trannies. The first time I heard Brahms 4 was on an example of the latter and the work has always given me pleasure, no matter the equipment (albeit it's nice to hear all the instruments in their proper place and a good dynamic range).

I think my understanding has always been that PRaT was to do with transient response (my assumption being that good engineering of transducers and reserves of amplifier power allowed these to be accurately delivered. And that a good system was dynamic and "fast". This might relate to "pace" I guess, but words like punch, slam, speed and dynamic all work better for me in this context.

I could never understand how "rhythm" was a good word in hifi context as it means something specific to a musician and really there does not seem to be a change in the rhythm between systems that I can tell, unless it's too subtle to be consciously noticed. I take the point about a good drummer (or any musician) adjusting the rhythm for emphasis but who is to say that any difference introduced by the reproduction of a recorded performance (if it is there) might be more or less attractive to a listener in the abstract?

As for "timing" some of Tony's posts here have been insightful and cause for thought. If speakers (for example) are indeed producing different frequencies at very slightly different times, maybe this could theoretically have an effect on the coherence of the sound perceived. I do wonder, however, if factors such as room reflections or listening position might have less subtle effects. It's an interesting point nevertheless and one worthy of thought.

 

[Fatmarley]

Firstly, those are extreme cases, created artificially. Secondly, even if the difference is audible, it won't be as a change in rhythm or timing.

I used to assume it was group delay that caused the difference between subjectively tight and boomy bass, but I have a ported speaker here that sounds tighter than a sealed, and yet group delay is higher with the ported speaker. Ported has a peak of 16ms at 45hz, sealed has a peak of 5ms at 45hz.

 

[misterdog]

having only been collecting records and hifi since the mid 70s (first Linn/Naim system in 1986), and having only the two music degrees and the one performer's diploma, - and having been a BBC sound recordist and editor, I do accept I'm at something of a disadvantage.

Odd that you need to ask the question then.

Maybe this hobby has no answer, merely questions.

 

[Nic Robinson]

Odd that you need to ask the question then.

Maybe this hobby has no answer, merely questions.

I think I need to ask the question because, as we have seen, the terms are not used with any precision. And different terms might describe the phenomena better.

 

[Paul L]

As for "timing" some of Tony's posts here have been insightful and cause for thought. If speakers (for example) are indeed producing different frequencies at very slightly different times, maybe this could theoretically have an effect on the coherence of the sound perceived. I do wonder, however, if factors such as room reflections or listening position might have less subtle effects. It's an interesting point nevertheless and one worthy of thought.

I think this is one of the reasons I like Vandersteen that I mentioned earlier, my understanding being that they have paid attention to time arrival/delay of drivers or whatever the correct terminology is, by no means the only ones to give it some thought. Maybe one of the reasons I like Martin Logan too, only the bass unit to align with the panel and with the latter handling 400hz upwards so all frequencies arriving at the same time. Unless that’s completely wrong and different frequencies have different speed, others here smarter than me will know.

But I really like my RS10 too so ultimately I guess I’m in that camp with others that we just like some stuff and with our precious leisure time we either switch it on, sit down and listen or we do other things. And no box-tick checklist with P, R, T, image, soundstage, time arrival, colouration, clarity etc. changes that acid test.

 

[narabdela]

I think I need to ask the question because, as we have seen, the terms are not used with any precision.

That's becoming blindingly obvious as the thread progresses.

 

[Sue Pertwee-Tyr]

That's becoming blindingly obvious as the thread progresses.

Much like real life, then. When conversing, people, as a rule, just say some stuff without carefully choosing their words. Sometimes they even use the wrong word. Communication is, nevertheless, perfectly satisfactory and very seldom do people misunderstand or fail to see the point being made.

I'm not sure whether face-to-face is easier because of body language, facial expression, tone of voice and other clues, or whether it's just being online that brings out the testiness in some people, but if we can perfectly well understand somebody speaking with imprecision, and the occasional malapropism, surely it's not beyond us to do the same with writing, especially as we have more time to take it in?

 

[sideshowbob]

The irony, ofc, is that Martin Colloms' original article was an attempt (failed) to bring some precision to how people described their subjective impressions. I don't think it's unreasonable to ask people to explain what they mean by a term when there is ambiguity, or when it has a precise technical meaning but seems to be being used in a different way.