What exactly is PRaT???


Ok, it’s like this thing and is associated with “toe tapping” and such.  I confess, I don’t get it.  Apparently companies like Linn and Naim get it, and I don’t and find it a bit frustrating.  What am I missing?  I’m a drummer and am as sensitive as anyone to timing and beats, so why don’t I perceive this PRaT thing that many of you obviously do and prize as it occurs in stereo systems?  When I read many Brit reviews a lot of attention goes to “rhythm” and “timing” and it’s useless to me and I just don’t get it.  If someone can give me a concrete example of what the hell I’m not getting I’d sincerely be most appreciative.  To be clear, enough people I greatly respect consider it a thing so objectively speaking it’s either something I can’t hear or maybe just don’t care about — or both.  Can someone finally define this “thing” for me cause I seriously wanna learn something I clearly don’t know or understand.  

soix

@gregm Ivor Tiefenbrun was a brilliant marketer for sure. He took the essence of British Hi-Fi and translated that into words to get awareness in the US market. I think Linn's products back in the 70s and 80s were not so different from other audio components from the UK, but the main difference was that Ivor created a "philosophy" to describe what that British Hi-Fi sound did well.

He got what many engineers miss about marketing. It's about trying to sell your strengths, not covering up all weaknesses.

My perception at the time when the phrase first appeared was that it was an anti spec approach to SQ evaluation.

Back then perceived quality of all audio components was based on spec analysis. 

@richardbrand

Of course, the actual music does not really slow down, nor change in pitch, nor timing (unless stylus drag actually slows a turntable down!)..

But our perception of when the beat starts is affected by the arrival pattern in time of the first transients of a note. If the leading edge is sharp, not smeared in time, your brain will snap into recognising the start of something special. I am suggesting microseconds here! Get this right, and you’ll likely find your foot tapping ...

Seems plausible.

@calvinandhobbes

The type of music you’re listening to matters in term of whether PRaT is relevant.

 

Perhaps I simply don’t understand how you are defining PRaT or perhaps it’s the fact that how rhythms are presented by a system is vital to my engagement as a listener, but either way, I’m having difficulty grasping how any genre wouldn’t benefit from a system that presents PRaT well. . . unless one is solely listening to ambient music that "hovers" in space. 

 

Unfortunately it’s not a given that people understand or are receptive to “prat”
And that is not a criticism, hence why many folk are quite happy with Alexa music , car stereo music Blutooth speakers etc .
Naim equipment does it very well.

 

PR&T is simply an essential component in well reproduced music. We all strive for well reproduced music.  I often say ‘wow, listen to that tune, listen to that PR&T’. I also say ‘wow, that’s great music’.

@yoyoyaya "... The irony is that the ... LP12 of the mid eighties had dreadful micro timing stability due to the movement of the subchassis/armboard relative to the platter. Linn’s mantra was pitch and rhythm."

I lived in the UK before Linn, when speakers were regarded as the dominant factor in audio quality. Ivor’s argument was that distortions introduced at the start of the audio reproduction chain were also important.

His starting point was that any sloppiness between the cartridge and the record would be amplified by the cartridge. His engineering solution was to couple the cartridge to the platter as tightly as possible in the direction of the arm tube. The bearings that allowed the arm to track the groove, and the platter to rotate, had to have minimum play.

If different materials were used, which expanded at different rates, changes in temperature would open up gaps. So every mechanical connecting component was made of the same grade of stainless steel. The soft floating suspension allowed the entire platter, sub-chassis, arm, cartridge system to move as one, keeping the relationship between the cartridge and the record consistent.

The most obvious difference from competitive players was the response to transients, especially scratches in the record itself. Others exhibited lengthy mechanical ringing whereas scratches were much less obtrusive with Linn. Ivor the showman illustrated this through his casual handling of records in demonstrations, often throwing them around. Elsewhere I have tried to emphasize the importance of transients for our perception of PRaT.

My recollection is that specifications were notably absent from discussions of Naim products!  The same went for the specifications of Rolls Royce car engines, where the output was described as "sufficient".

 

Music reproduction systems produce sound waves that can be characterized by their amplitude, phase, and any added distortions.  Pace, rhythm and timing is something music has.  Unless you are using a turntable running at the wrong speed nothing in your system is going to change pace, rhythm, or timing.  The PRaT that audio writers prattle about is an illusion caused by dips and bumps in the frequency response of speakers or turntables.  Everything else has ruler flat frequency and phase response.  More or less PRaT in a solid state amplifier or DAC is purely imaginary.

@stuartk I would agree that all musical genres benefit to some level from better PRaT, but my perspective is that whether PRaT is a key element to understanding the music will vary by genre. Some musical genres like jazz have frequent quick interactions between different musicians. Better PRaT makes it easier in my experience to follow what's going on in the music. Orchestral music, as a vast generalization, tends to have interactions between the different instrumental sections that is of a nature that is not as quick and transient as those in jazz music.

@calvinandhobbes 

Orchestral music, as a vast generalization, tends to have interactions between the different instrumental sections that is of a nature that is not as quick and transient as those in jazz music.

Thanks for kindly pointing out what is probably obvious to many, here. I tend to favor smaller groups, which means I rarely listen to Big Band Jazz and never listen to orchestral music. My comments reflected my unfamiliarity/ignorance.

 

@rwortman

. . . The PRaT that audio writers prattle about is an illusion . . .

. . . and yet for some us, at least, the presentation of pace, rhythm and timing is discernibly different from one system to another.

@audition__audio 1+

@dogearedaudio There are several aspects to stereo imaging that help define a systems performance. Imaging specificity is essentially the "focus" of the image. With the best systems and recordings each instrument and voice is sharply defined in 3 dimensional space with "blackness" (no sound) in between. In most systems the individual sound sources blend into each other. With a large number of instruments, like a symphony orchestra there is a solid wall of sound. Instruments still occupy a location, but they blend into each other whether one likes it or not.  Imaging the third dimension is not where in instrument is located in 3 dimensional space it is the sensation that an instrument or voice is not a flat object on a painting but a three dimensional object in space. This is the sensation that the singer is in the room with you. This is the hardest aspect of stereo performance to achieve. Very few systems will do this and only with a limited number of recordings. A 3D soundstage is imaging in 3 dimensional space. Some instruments are up front and others behind. In many instances this is artificial. The recording engineer is doing this with echo. It is best to evaluate this with a live recording as fewer tricks are used in their production. A good recording of a symphony orchestra should easily demonstrate that the tympany is at the back of the stage. 

Sometimes audiophiles will refer to a soundstage as being wide and will relate that their system images out beyond their speakers. You can throw an image beyond the speakers with phasing tricks, but in the absence of these the system soundstage should be defined by the distance between the speakers and the listener's distance from the speakers. Imaging beyond the speakers is due to reflections off the side walls and always represents a problem that diminishes image specificity. For a system to have the best image specificity the frequency response curve of the two channels has to be identical. This is very difficult to achieve usually due to room issues. This is not to say the frequency response of a system should be flat. To the contrary systems tuned to be flat sound bright and bass less.    

As a former musician PRaT never clicked with me in home audio until a full Krell class A system with Thiel CS3.6 cycled through here.  @soix , I can only relate my experiences playing in bands like this.   When everyone is locked in perfect synch with tempo, perfect attack and release, volume and balance, there is an undeniable completeness to the sound of the group.  No early flams, no hangover notes, no smearing of staccato passages, running musical phrasing is in lockstep to the point that every note is heard but none stand out in any way.   The band speaks with one voice.  
I have listened to recordings of myself with excellent musicians and always hear the original performance to some degree or another.  We had a few sessions that were “tic-less” or without error for those non band / drum corps folks understanding of that word.  Tic = timing error.

The combo of class A and phase coherent speakers opened my ears to the most accurate presentation of music I was intimately familiar with.  No smear of any sort.  With that system in place and only speakers rotated through, I became aware of crossover / driver anomalies that slowed the edges of notes, broke the synchronization of percussion with brass and slowed the output of ranges from treble on down.  The music was all there, shading and dynamics etc etc, but the recordings lost that lockstep timing or unison, a Slight blurring of instrumental notes that is normally undetected.  Speakers have been the bigger culprit in the change or lack of PRaT for me.  Electronics and cabling can have some deleterious effects but driver and crossover implementation tend to wave a bigger flag for me when it comes to decreasing PRaT.   For me full range speakers that marry woofer, mids and tweeters in phase and speed offer that sense of unity or unison

 

@soix - not knowing PRaT in audio components may be a blessing - one less thing to detract from the music

I find this interesting.  I'm with soix as I too have difficulty pinning down the understanding of PRaT in audio components.

I understand what is musical drive, but cannot put into words. I understand when orchestra timing is off, but when it focuses music beauty and drive take over.  I get the gist of @atmasphere in that increasing component sonic errors leads away from emotional engagement towards the analytical as we're wired to single out things that don't fit.  

When evaluating components, I do the usual test tracks: own familiar songs, test cd songs, acoustical instrument reproduction, etc. specifically paying attention to voices, piano, violin, bass definition, etc.  When choosing a component, I choose one that "resonates" with me (sounds great top to bottom, pulls me into the music) like Magico, MBL, YG.  Likely PRaT is a subcomponent of "resonates" that I simply haven't isolated separately

OP…. As the old line goes about jazz… Of you have to ask, you’ll never know….

To me, PRaT is a subjective (although not stupid) term.  To me, it refers to how realistic the music sounds, i.e., does it sound like you are there?  Does it give the illusion of a performance right in front of you, with depth, width and proper tone?  Since that is so dependent upon system, synergy, room size and treatment, etc., it can only be subjective.  I never refer to PRaT for that reason — I just say that my system makes me feel that I am there witnessing the performance, wide and deep soundstage, etc.  Those are terms that although they are subjective, they have some general understanding among the audiophile community.

It means the music is vibrant & the musicians are playing together. So the meaning of the song comes through. 

@soix 

I thought I understood the concept to mean musical pace, rhythm and timing.  However I have come to think of it as more than that- explanation in a minute. 

A system with a lack of PRAT sounds mono level- at a micro dynamic level, minor swings in volume, not opposed to big swings in level which is different- meaning all sounds tend to be banded together in a limited micro bandwidth and when listening tends to sound flat and unexciting, like the music just sits there by comparison.  

However once I acquired fast speakers and a fast class A amplifier PRAT took on a whole new meaning for me.  It was no longer just about rapid transitions in micro dynamics, it also became about musical element separation and audible distinction.  Musical elements became much more on their own in space, relative volume level and distinction / clarity.  It was as if each voice or instrument had its own physical channel and speaker.  Everything stood out more on its own and quite amazing.  The music and sound had much more contrast which let the pace and rhythm of each instrument become clearly audible.  A drum track in the background was much easier to follow and focus on because it was much more delineated than with a less dynamically capable system which seemed to blend everything together.  

@bryhifi 

 

Great comments. I never thought of it that way. Good analogy. 
 

I just want to point out again that PRaT is probably the most difficult parameter to sense. I know many folks that do not know how to detect it yet. But with thought and careful listening you probably will eventually. And that is likely to be a real epiphany.

False orthodoxy is prone to pop up in high end audio, and PRaT is one such. I know what it is--and have successfully ignored it for decades.

Nevertheless, this is an amusing thread. I like that it brought out a couple drummers. My favorite comment:

"...it was hard to hum and toe tap to Schoenberg"

Mrs. Schoenberg would beg to differ....

I don't own Linn or Naim equipment so  I guess I'm not aloud to talk on the subject.But the feeling of the music and vibration, from the open track seem to tell the story. I GUESS....

IN high end audio it is the MUSICAL flow of the music.  When you hear a system does it give you foot tapping body moving experience?  Or is it analytical sounding where it could be clean sounding but dull dead and no foot tapping.    I always interpreted it to be the musical flow of the music!

Play this song, a not so great recording on a relatively crappy rig and it could still sound like great PRT.

A musician can give you good PRT even if everything else sucked.

 

Chris Rea - I can hear your heartbeat, 1983 version

https://youtu.be/OwOV8HyQyKk?si=4GdniWVv97YKRpn6

Play another not so great recording on a lousy rig and the musician still gave  you some perception of great PRT.

 

Bombino - Niamey Jam

https://youtu.be/ActhAx-374o?si=x3VsT9nv8PoBUkQd

That Chris Rea song is garbage. Hard to find PRaT in garbage. It’s got everything that made music suck in the 80s. Bombino is a better example. It still seems like no one can come up with a definition but plenty of examples of what they think it is. Seems like it’s more a quality of the song and whether the system can reproduce those qualities. If that’s the case then shouldn’t there be some way to quantify what makes the system do that? Whether it’s transients or decay or midrange quality or phase coherent drivers or even room treatments.  Basically something like if you want a system that can reproduce PRaT then it needs these n number of qualities.

@bolong

Master of PRAT ie."swing"

You might check out this analysis, exploring how Little Wing in fact incorporates both straight time and swing, which is why it’s deceptively difficult to get right:

https://www.youtube.com/watch?v=0uGDYs__ZP8

 

PRaT is experiential, and as such takes some experience to hear - or not hear. It's pretty clear it does not exist in any one domain, like frequency, or phase, per se. The Large Advent is great example - beautifully voiced, extended well controlled bass, but PRaT? Not so much. My explanation is hysteresis - the delay between input and output. Hysteresis may vary due to a lot of factors, amplifier damping, a function of output series resistance, including the amp, speaker cabling, crossover series inductor (one reason internally amplified speakers tend to sound 'quicker') and overall speaker alignment. Acoustic suspension speakers rely on compreesion of trapped cabinet air for damping, and are as a result inherently slower and less linear to stop, resulting in a smear that doesn't show up in frequency response graphs. By comparison, full range drivers, for all their other limitations and freed from those driver control constraints tend to have that ineffable 'liveness' that they are known for.

Likewise, much of the difference between MM, MI, and MC phono carts can be attributed to their inductance, with MM carts having 10X the series inductance - and resulting hysteresis - of most MC carts, with MI like Grado and Soundsmith falling in between. 

As for amplifiers, the ability to control and dissipate the woofers back EMF (the 'brakes') is likely their major contribution to PRaT. 

Overall, I believe PRaT is fundamentally about controlling and minimizing stored energy within a system. It is the release of that stored energy that smears the sound, robbing the music of PRaT.

I agree that PRaT is primarily a subject term that's used to describe a feeling/experience where you find yourself sucked into the music and absent mindedly tapping your toe.  I have experienced it with my system on certain recordings.  From a system perspective, I think that some components tend to excel in the frequencies ranges that can be correlated with the desire to "boogie" so more often bring it out from recordings compared to other components.

PRaT, in my book, also has clean delineated ’plosives. part of the package.

It requires a clean start and stop of a transient, with no out of phase smear or lag in the signal additions that are unwanted, which would cover up the fine aspects of the plosive or transient. the requirement is one of a clean wideband low distortion and high signal to noise ratio signal reproduction. That’s what it takes to get a plosive right. Live amplified vs reproduced. the trick is, of course, to get the reproduction to sound like the live and amplified.

When all that is working, we can naturally and natively extract or witness ’PRaT’ in the amplified and reproduced signal..

PRaT seems like the pornography of the audio world, I can’t define it but I know it when I hear it.

I can definitely feel the toe-tapping quality in the Bombino and Chris Rea songs. At the same time, I can't disagree that Chris Rea was garbage, so it seems PRAT and crappy music are not mutually exclusive.

I can feel no PRAT in the Stevie Ray Vaughn piece nor in thriller, however.

Considering that PRAT clearly manifested through the diminutive speakers of my Pixel phone, I would venture that PRAT is very real but that it can safely be ignored as a selection criterium for audio equipment. PRAT lives in the music, not the system, and I can't imagine equipment so bad it can't reproduce something a smartphone can.

@stuartk
You might check out this analysis, exploring how Little Wing in fact incorporates both straight time and swing, which is why it’s deceptively difficult to get right: https://www.youtube.com/watch?v=0uGDYs__ZP8

 

Thx for posting a link to this video. I found it fascinating. The presenter did a great job.

@soix

This “toe tapping” thing is just totally lost on me, and I guess I’m just missing it or don’t hear that way.

 

I hear you buddy you can not hear PRaT if your focus is on the beat that everybody else is following for proper timing. Possibly you hear everything else not supplying the beat as being one or two steps behind the beat that is being generated. Drummers are the foundation if they are off chasing something else everything is just going to fall apart but they do disguise their metronome by laying down some cymbal decay to cover their tracks and fills to punctuate what everybody else is doing to disguise it.

....20' above it, 50 yards from the mudfield....slept through the night mostly, waking to heavy rain and the winds.  Nil damage.

@asvjerry  , straying from OP's topic, I am happy to read that you were spared from the major devastation.  It was horrific to see on television, and I cannot imagine what it would be like to actually experience losing everything.  PRaT takes a back door to that.

Back on topic, after following this thread for a bit now, as nearly as I can ascertain, PRaT seems to be in the ear of the beholder.  If it gets your toe tapping it has PRaT?  In that case, although my system is hardly 'end game',  I've been listening to and experiencing PRaT for quite some time without realizing it.  ​​​​​​

Just got the Prat reference 

Lerxst, Dirk and Pratt will not soon be forgotten as the best rock band of all time.

Let loose the the dogs of war

Tony Rice, one of the legendary flatpickers, explains how his bands let the music breathe by mixing beats or a he rightfully calls it "pulse.

"Tony Rice On Time In Music

I've posted that in my opinion PRaT relates to the time domain, not the frequency domain that we usually talk about.  To the person that never listens to symphonic music, I would ask if that extends to films which use such music to underscore the drama?

Classical music almost always does have a beat, it is just not as in-your-face as some other genres and can be very complex and rewarding if you get it.  A big orchestra faces a big timing problem though - the visual clues from the conductor travel at the speed of light (near instantaneous) but sound is much slower.  It takes almost 1/10th of a second to travel 30-meters.  The Sydney Opera House Concert Hall stage is about 19-meters wide and is small for a major concert venue, because of the concrete shell surrounding it, although it is comparable with the Berliner Phiharmoniker  I pity the organist sitting high towards the roof looking in his rear-vision mirror down at the conductor in the distance!

Nevertheless conductors like John Wilson can make a good orchestra rock ...

@bolong ...Re Cha-cha cha...."Fascinating, but you can't dance to it..."

Dense....dwarf star alloy level, if speed read you will bruise one's brain...

MHO, and I'm stuck with it. ;)

@immatthewj ... It's been and will continue for quite awhile, an Experience.
Can't say recommended....but the Pause to look about you and consider....😔

Yes, back to PRaT falls... ;)

Hey, if what you listen to doesn't make you 'move' in some fashion, physically and/or emotionally, in yet another mho, you're listening to the wrong stuff.

Ultimately, the means that you apply to create that grand illusion for as long as you love or tolerate it despite the bugs ignored to do so....

...IS the Point.

*blink*

PRaTically guaranteed .... ;)

'ciao, J

PRAT is Brat.

@soix have you ever listened to a Naim system from source to speakers?  Or Naim electronics with ATC speakers?

I got back into the hifi hobby about 20 years ago.  I was traveling for work at the time and would visit brick and mortar stores all across the US, and I listened to all kinds of systems from budget to quite exotic.  There were surprisingly few setups that actually moved me.  One that did was a Naim CD player and Nait XS integrated amplifier with Naim floor standing speakers.  Not the last word in detail or power, but it just sounded so incredibly “right”.  The music had momentum and flow, and yes it made me want to tap my toe.  I later decided that is what people are talking about when they say “PRAT”, and wondered what engineering trick or emphasis was employed to achieve it.  I could have listened to that system all day.  I had an opportunity to hear some very high end Naim gear at the time, and while the detail, lack of distortion, spatial representation and power of the music were clearly better, the music seemed a bit more sterile compared to their more entry level gear.  (Naim’s newest higher end gear has it all however.)

I have thought about what I consider to be “PRAT” a lot since then, and have been chasing it in my systems, while also trying to achieve what I consider convincing imaging, dynamics and tone.  If you don’t “hear” PRAT in yours or others systems, but you are enjoying what you’re hearing, I wouldn’t worry about it.  I enjoyed listening to recorded music immensely for years before becoming aware of PRAT, but now I can’t un-hear it.

Someone mentioned Tony Rice previously.  I find his work with David Grisman’s Quintet and Grisman’s dawg music in general from the late 70s and early 80s to really swing and be loaded with PRAT.  The recording by MOKAVE called Afrique is another great recording to test your system’s PRAT capabilities.

YMMV

kn

@panzrwagn "Overall, I believe PRaT is fundamentally about controlling and minimizing stored energy within a system. It is the release of that stored energy that smears the sound, robbing the music of PRaT."

I think you’re right on the mark based on my listening experiences. Two categories of components that seem to inhibit PRaT from my perspective are:

  1. High mass turntables
  2. High powered Class AB amplifiers

Both store a good amount of energy from what I know: high mass turntables are slow to release vibration and higher power amplifiers need larger power supplies to handle the bigger current demands.

@bolong Agreed with your statement that "It requires a clean start and stop of a transient". I agree that I don't think it has anything to do with timing per se, but rather having sharp leading and trailing edges for when a sound wave starts and stops.

@calvinandhobbes 

I think you’re right on the mark based on my listening experiences. Two categories of components that seem to inhibit PRaT from my perspective are:

  1. High mass turntables
  2. High powered Class AB amplifiers

I never experienced PRaT until I acquired my Hegel H390 (Class A/B rated at 250 watts @8 ohms). 

@steakster

You’re welcome. Glad someone found it worthwhile. Those guys are two of the best player-teachers online.  

 

Ah, Chris Rea.  First heard "The Road to Hell" in a clapped-out army truck descending into the Great Rift Valley in Kenya, with truck wrecks littering the landscape.

Later I was MC for a conference and had a copy with me.  Played it as attendees drifted in, the morning after the big dinner.  A colleague rushed up: "the sound system is broken".  All he could hear was raindrops and windscreen wipers.  Then the first crescendo hit.

Chris really cares about the quality of sound, and all his recordings are studio-made.  I heard him live in Melbourne and he was absolutely mortified that he could not get the exact sound he wanted.  He never toured the USA

Herb’s latest and recent reporting on an actively configured vintage horn/tube setup, a rarity (i.e.: active) with this kind of setup, where he goes:

A couple of minutes into the first demo disc, I started bouncing on the couch raving about the boogie-PRaT factor. [...]

Notice the inclusion of the more layman’s term "boogie-factor" as a variation of PRaT, the latter of which seems to have been described around here as a somewhat over-complicated and esoteric attainment to come by through years of audiophile cultivation and final revelation(?). I can only assume that for those it’s a rare (and late) trait to have experienced, not because it’s the Sasquatch of audio qualities but simply due to setup choices that didn’t bring out the boogie-factor (sorry, PRaT) in a prevalent fashion. Oh, I can imagine seeing PRaT entering what has otherwise been a stale audio serving through years being something of revelation when it adds up to the other qualities that has been meticulously harnessed over time, but making it a matter of an "enlightened progression" over decades is just going off the rails in my book.

Maybe to some it’s the other way ’round; they attained PRaT long ago and earlier in their audiophile journey, and only later added the perhaps more conventional audiophile traits of imaging, resolution, airiness, balance of presentation, etc. As is I can definitely attest to the importance of boogie-factor/PRaT as a vital sonic ingredient, on top of many other things.

@richardbrand 

Classical music most certainly benefits from a system with PRaT.  In that case, I call it the "air-conducting factor." ;-)  Just the other day I listened to a marvelous stereo broadcast of Pierre Monteux and the Boston Symphony performing Strauss's "Don Juan" at Tanglewood.  If that performance doesn't get you out of your chair and waving your arms, nothing will.;-) So much joyful swing in the rhythms and phrasing!  I want to hear Furtwangler pounce on Brahms, or Rosenthal turn Debussy into a dance date, or Klemperer hammer away at Beethoven, just as much as I want to hear Basie bounce or Goodman swing. ;-)