PRaT - Why can't we measure it?
Posted by: Harris V on 18 December 2000
I am no electronics expert but am wondering why it is such a hard thing to measure? My issue lies especially with timing - which from A level physics I remeber had alot to do with leading and trailing edges of pulses and wave forms. I also remember that this could be measured with an oscilloscope. I realise that musical signals are very hard to model (very wide frequency range) but surely we could come up with a signal sufficiently simple (several overlaid sine and square waves??) that would allow us test various amps back to back and find out once and for all if Naim amps do timing better.
I don't think that Pace and rhythm would be as quantifiable but we could measure distortion , background noise and rounding (of sharp edges) easily enough. (Although I have always thought that some of Naims 'pace' was due to a slight lower bass lightness, especially in Naim speakers).
I do trust my ears but curiosity and too much forum is driving me to science.
Does anyone have the equipment or am i oversimplifying.
"Pace, Rhythm, and Dynamics" by Martin Colloms
I used to be a technician many years ago - and I knew that there is no measuring equipment in the audio area that is as fast and as accurate as our hearing system, I guess the same is now.
Our hearing system compares continuously signals
with a very complicated structure that apear in both ears at a very few millisecond changes and time shift between the two ears.
As far as I know, no mechanical/electronic system can follow this very fast and complicated procedure.
Arie
The limit of my analysis is that PRaT is a subjective assessment and that the links from this assessment to the physical components that contribute to this assessment are nebulous and undefined.
Example. Why do Naim DBLs sound better than Martin Logan ReQuests to me (although as an aside I can immediately pick up on the DBLs slightly wayward tonal balance - Its just that I don't care compared to their ability to 'swing')? In any conventional measurement the Martin Logans pee on the DBLs - from a great height. This leads me to three problems, how do I quantify 'better', then how do I translate this into physical phonomena and how do these measures interrelate - by this I can get of Measure of 'Betterness' and engineer on it in a qunatifiable and measurable manner.
I guess that this is not the way Naim work. Ears are used as the ultimate measuring tool. After all Naim are a commercial business not a university - although the University of Essex does research in this area - any of their graduates around?
Alternatively, I can get on with the business of saving for my technically inaccurate speakers.
[This message was edited by Martin M on TUESDAY 19 December 2000 at 08:52.]
'God is in the Nuances':web page
Regards,
Martin
"I like this rose, it smells better to me than that rose, the colour is more appealing to my eye."
Would PRaT by any other (than) Naim sound as sweet?
Possibly to someone else but not necessarily to me.
Most of us who play instruments, however badly or well, recognise that music is an emotive thing. I drives something deep within us. I could play you a piece of live music which was technically perfect but thouroughly void of expression, nuance, life and what I like to call "soul". You may, on hearing the music agree about all the measurables, pitch, precision, tempo. sustain etc. and yet remain unmoved because the soul is missing, I'm uninvolved with the music and so are you. Now, most music is played by folk to whom it means something. Playing is as satisfying for them, if not more so, than for the audience. Playing for a small audience or a large audience (money aside ;-)) may well be irrelevant. It's about involvement with the music.
Some kit is capable of drawing you into the music of a recording in the same way that the live performance would. Sure the measureables may not be "perfect" (whatever that is) but the performance is reproduced with"soul" and is involving.
I've heard people play where the tuning hasn't been perfect or a string's broken halfway through a piece but they played on and for all it's measurable inperfections the result is involving and moving. Who hasn't heard a small child or chlidren singing in it's/their own inperfect and unaffected way, oblivious of being heard, and not found it moving, just for the sheer delight expressed in the song; the words are wrong, the timing's out the notes are slurred and most parents wish they'd recorded it anyway - it's an emotional thing.
I suspect most of us are quite content with our own internal measurement scale and those I've met who measure emotional things by an external and arbitary, beacuase it's unique to them), scale are usually very disappointed and unsatisfied people. (This year's present is smaller than last year's present - they love me less.)
0.02 Euro's worth
regards,
Mark
Excellent post, and one I wholeheartedly agree with.
Music is, to me, totally about emotions. This is why it is som important in our lives, in that it can change the way we feel just within the space of a single song.
I think that the term PRaT (which I am guilty of using myself) does not help here, I think musicality (which admittedly sounds vague) describes the emotional element better. This is the bit I want my Hi-Fi to do, to make me laugh, dance and cry to make me FEEL something deep inside.
As you say, it's a personal thing, and even our own personal emotional responses vary from day to day, depending upon our current state of mind.
As to how one designs equipment repeatedly and reliably to recreate these emotional effects is something I think Naim will want to keep as a closely guarded secret!
Andy.
Andrew L. Weekes
alweekes@audiophile.com
So, why is it I fall asleep to The Meters played on Martin-Logans (I'm not singling them out for criticism - just using them as a personal example) but are well up for it with DBLs?
I can't think of another example where the delivery means makes such a difference. For example, I can follow the plot to Alfred Hitchcock's Vertigo on a Sony Television as well as I can on a equivalent Panasonic. The basic premise of the film is to play with one's emotions - the same as music - however I don't percieve any difference in emotional impact when viewed on each television . In information theory terms the film and television are far more testing than audio and the eye is a very acute instrument. So why is audio critical and video not? Perhaps we are not measuring the correct things or just do not know there relationship to emotion in sound whereas we are and do in video.
Over to you!
I also think your point about analysing your system in a quantative way (I mean only not based on what you are feeling) is the way to being deeply unhappy with your hi-fi and also a route to upgrade-itis. The best dealer I know asked me to leave his shop because I did not have an answer to his first question: Why do you want to upgrade?
However.... the engineer in me, whilst convinced of the above arguments, refuses to believe that some of the differences in the output waveform of a Naim amp compared to that of another amp cannot account for some of the emotion that the amp can impart. I don't want my amp to be a wire with a gain either but I cannot deny my curiosity to what it is actually doing.
I think the points you raise indicate how little we know about human perception to emotional stimuli!
quote:
So, why is it I fall asleep to The Meters played on Martin-Logans (I'm not singling them out for criticism - just using them as a personal example) but are well up for it with DBLs?
I wasn't trying to imply the delivery method was unimportant, just that any attempt to quantify how delivery method relates to our personal perception seems difficult to assess. I'm sure there is a corellation between emotional response and techical criteria, but I'm not sure I know the criteria.
The most interesting one for me is the case of FM radio. Many people think that a NAT01 provides one of the best source components available anywhere, yet, in terms of audio bandwidth, FM broadcasts have a limited high frequency extension, when compared with other sources. Does this make frequency response unimportant or just less important? Taken to extremes it obviously is important, maybe it's a question of balance?
JV also quoted the example of the telephone in a previous interview, one can tell, even down a bandwidth and dynamic range restricted medium , a lot about the emotional state of the person at the other end. You could tell if they're happy, sad, lying etc. - what information is being portrayed to allow this?
quote:
I can follow the plot to Alfred Hitchcock's Vertigo on a Sony Television as well as I can on a equivalent Panasonic
This I'm sure is true, but if you were to watch it in a Cinema would you feel any more emotionally involved? Would it become a more immersive experience?
Additionally, is that due to the larger screen, the audio content or just the different environment?
As an engineer one part of me wants to quantify an analyse these elements, the other part of me says who cares - it's the end result of the experience that counts!
Whilst it is commonly attested that the video is more testing, I'm not sure I agree with this. I think JV's previous comments about designing for 10 octaves and a 120dB dynamic range (if memory serves me correctly) at the same time make audio engineering a unique field.
The ability of better equipment to constantly 'find' more information within existing familiar software indicates to me we have yet to extract all of the available information from our source materials, implying that there may be more information within the audio data than meets the eye (or should that be ear?).
Video would seem to suffer from an inherent limitation in this respect, or is it just easier to quantify and extract the data and present it to the viewer?
As for the eye being an acute instrument, in raw scientific terms this may be true, but it's output is filtered significantly by the brain. I can demonstrate a number of examples whereby I could show someone a sentence with a significant error within it (repeated word) but most people would not see the error, owing to the way the sentence is presented. Maybe the ear is not so easily fooled / filtered by our expectations of what we expect to see / hear. A recent example show to me asked me to count the number of times a word appeared within a sentence - most people were inaccurate by a significant margin, seeing only 2 or 3 of 9 occurences!
Lots more questions here, and I don't have the answers, but I do find the discussion VERY interesting.
Andy.
Andrew L. Weekes
alweekes@audiophile.com
I agree with your point about impact getting better as the technology gets better vis-a-vis TV to Film. However, this seems to defend my point about us having a 'Measure of Betterness' for video emotion(resolution, screen size relative to real life etc) but not not for sound emotion; hence my Martin-Logan (very good technically - a very low amplitude, phase and harmonic distortion speaker) vs DBL (not so good technically -scewed amplitude and phase) but who cares the DBL's music is better. That is also why I chose two essentially similar media for video as they have the same level of video emotion hence can be used as a 'datum line'.
If this so, thanks for agreeing with me! Otherwise, I've misunderstood you, sorry.
I agree with the two senses bit, thats why I dim the lights a bit when listening - Roger Daltreys voice coming out of the fireplace is a bit odd...
Anyway, I must say this is very erudite and interesting thread. Its a pretty we aren't in a pub with a few beers.....
quote:
I agree with the two senses bit, thats why I dim the lights a bit when listening - Roger Daltreys voice coming out of the fireplace is a bit odd...
Do all of us do this - I often sit in total darkness whilst listening to music, the visual stimuli can be distracting, I feel.
Another interesting point is that video without audio would seem to me to be quite dull, yet audio without video can be totally captivating.
Do any of you out there find yourself emotionally stimulated by, for a example, a great work of art in the same way you are stimulated by a great piece of music?
Personally the visual arts do not 'do it' for me in the same way, but there may be others for whom visual stimulation is equally rewarding.
Andy.
Andrew L. Weekes
alweekes@audiophile.com
Mike
I think this is a good point - what separates great music performance from mediocre is the attention to dynamics with respect to time. Sometimes it makes you jump, sometimes lyricism makes you cry. That's all I want from reproduced music, the opportunity to respond emotionally.
David,
Tick, 'Agree Strongly'
Somehow I feel these two items are linked. Reproductions are all we can aspire to most of the time, but the moment of original discovery - the immediacy of experience - is what lends vigour to emotion. Words like 'scale' 'dynamics' and 'PRaT' are feeble ways of trying to quantify our relative poverty of vigour ...
Martin
One other tack to possibly take on this subject is to define sound and define music. Once this is done (if it can be done without resorting to nebulous terms) perhaps we will have a framework for calculating why some seemingly inanimate objects (amplifiers. speakers, stands!!) can alchemise great music into mere sound.
Anyway, I'm in for the beer - perhaps post Naim forum members tri-amp 500/DBL dem. I know nothing of Bristols pubs so any suggestions are welcome.
quote:
I cannot promise to be erudite.
I can promise to drink beer.
I think I could manage the latter also, along with a guarantee that my tongue will loosen as the intake increases.
Whether it will be erudite is debatable. 
David,
quote:
Personally I've found visiting art galleries on occasion to be as profoundly moving and even life changing
I've yet to have this experience in the way that good music can stir my emotions.
I wonder how much of it is a learned response, as I'm much more confident that I know what I want my Hi-Fi to do now than when my interest first started, years ago.
Out of interest does an original piece of art that is a reproduction (in effect) of something real have the same effect on you?
The more I analyse the more questions I have!
Andy.
Andrew L. Weekes
alweekes@audiophile.com
I shall have to do some work soon as well...
I was thinking of works of art that are a reproduction of a 'real' thing (e.g. a landscape).
I'm probably just displaying my artistic virginity by asking such questions, but I shall investigate the works you mention to see if anything stirs 
Andy.
Andrew L. Weekes
alweekes@audiophile.com
After Dunblane, when I saw a photograph on TV and in the newspapers, showing the class that was targetted with the fatalities ringed, I cried because one of them looked uncannily like my daughter.
I have never been moved to such emotion by music.
What am I saying? I am not sure. Would a blind parent have such a reaction to someone else's grief if they heard it on the radio?
For most people visual images are the most potent and are supplemented by sound and of course informed by personal experience.
cheers
Nigel
There were attempts to describe music with mathmatic tools - but all these attempts failed.
If you can't describe it in a mathematic way - how do you suppose to measure it ?
Arie
However, if music isn't moving you then maybe you are listening to the wrong music. Some music can gain a lot in poignancy when you know the context behind it. Some music includes lyrics which can move you. Some music is powerful on its own (as Nick Cave screams I AM THE KING in my room). As to the photo of the disaster, perhaps some politically engaged music might move you in like manner.
--Eri
"Maybe we should have a "Musical Appreciation 101" session in a suitable pub during the Bristol show in Feb?"
As I mentioned on a previous thread I will be posting a list of pubs, cafes & restaurants nearer the event. For now I might suggest either Watershed or Mud Dock.
Both are on the harbour side & offer good food & booze. I would favour Watershed for it is larger & offers more scope for 'taking over' a corner of it. Great selection of very reasonably priced food too.
Bob
Thats because they aren't depresing in any way. They inform us of the bleakness/absurdity of our position but this is the exhilarating, cathartic and underpins the greatest art. See the sculpture of Giacometti, the music of Thelonius Monk like minded souls to Beckett. The greatest joy of Beckett is to me the sheer humour of his plays/prose the relish and laughter of the pain of existence. Not many artists see this far into our souls.Hes a funny man too.
I feel uneasy with the use of real life tragedy as a point of reference in this discussion. Art may help us understand but the cheapening of real emotion/pain by the falsity of retelling by television/newspapers is surely a horror of our age. Voyeurism as opposed to empathy.Im not denigating the reactions of others here but voicing a concern.
John ( A pint of plain is your only man)
[This message was edited by John C on WEDNESDAY 20 December 2000 at 00:09.]
quote:
Nigel, I'm not sure about this, what little research I have read suggests that visual / audio etc input as 'main carrier' varies a lot between people
This is an interesting point. I have at least one friend who seems to be incapable of listening, for example, to comedy on radio. They enjoy comedy, but seem to lack the ability to listen to it, needing visual stimuli (even though the comedy may be spoken) to appreciate it.
This same person listens to music, but only of the very light and frothy pop type and primarily as a background to other activities - I guess that this person is a visual person.
I find good comedy on radio as captivating as that on the Television, and will quite happily listen to radio drama, happy to create the imagery in my head. I assume then that I'm probably more of an audio person.
My only thought on this is to wonder if this is a nature or nurture issue?
Andy.
Andrew L. Weekes
alweekes@audiophile.com
See you all there too maybe.
regards,
Mark
As for Beckett I much prefer the later prose to the plays which lose their way a little for me. I still enjoy the pain and despair. Im with you all the way on the reclaiming of art, poetry, literature, jazz music, from the various elitist (financial,class,intellectual, whatever) organisations who ossify and destroy it.
Christ this sounds pretentious!
John (A pint of plain ...) ^