Prat

[MylesBAstor]

Pace/Pitch
Rhythm
Timing

Definitely three important components in music.

And musical reproduction. Especially rhythm. (Some might argue that the biggest faux pas for a musician isn't playing the wrong note but losing the rhythm.) For it's not just simply playing the note that counts, for instance, but how the note is played that differentiates and makes that jazz guitarist have swing. And swing probably has a lot in common with defining PRAT:

"It’s that swing cannot be defined by anything that you can write down."

"Listening to different players swing, you can observe a number of variables that each player uniquely expresses with respect to their style of swing:

• The ratio between the lengths of adjacent notes.
• The accent of specific notes.
• The articulation of adjacent notes.
• The precise placement of notes in relation to the time.
• The way the fingers move in correspondence with the tongue (just fingers for non-wind instruments). In fact, John Coltrane told saxophonist George Braith around 1966 that he had developed a definitive way to close the keys, which would allow him to achieve clarity in his lines without relying that much on his tongue (Simpkins, 235).
• And just like most aspects of this music, infinite gradations of subtlety."

I've avoided the subject of PRAT for some time now because it seemed like a catchall term for so many different things going on the system. And in some cases, a not so pleasant artifact of the system. For instance, a ringing in the tonearm that gives the impression of timing.

Why then did I decide to raise the subject? Because a a manufacturer and I got on the subject of why electronics, speakers--and most notably turntables--sound boring. I'm sure everyone has had at one time or another encountered that situation where you bring a favorite recording to one room and it sounds wonderful; then in the next room, you fall asleep. What gives? Or take the case where for the same quality turntable, a LP sounds great on one deck and totally different on another?

Then I chanced upon this old piece by Martin Colloms that appeared in Stereophile almost a decade ago where he delved into the subject. Probably the most controversial aspect of this piece then was Martin discussing that PRAT not only applied to turntables but every other component in the system. To be sure, you can even hear how cables can affect timing and rhythm.

Certainly timing and rhythmic losses are attributable to smearing. Old mylar and polyester caps. Badly designed power supplies. Badly designed belt drive tables (in fact, it was the subject of belt vs direct drive tables that brought the subject of PRAT to the fore). Crossover design. So in the end, pretty much affects PRAT in the system and one link in the chain can make or break that timing and rhythm of musical playback. But there also so many other factors that go into PRAT that one could spend pages enumerating them.

What's everyone's opinion and experience with PRAT? Is there anything in particular that you've done or paid attention to in order to optimize this aspect of musical reproduction in your own system?


.

[Bill Hart]

Doesn't the acronym have another meaning as a British term of art?

informal

• 1British An incompetent or stupid person; an idiot.

Per Oxford Dictionary Online.

What a hoot, Bill!

Makes me wonder what Reiner would say about PRAT.

[mep]

You are correct amingo Bill. In Maine, instead of saying someone is a prat, they would call them a "dubbah." You never wanted to be known as a dubbah.

[mep]

I for one never liked the term "PRAT." It was commonly used by semi-pretentious audiophiles who still think the sun rises and sets on Linn tables and Naim electronics, as well as their asses. I always looked at Linn lovers as a cult. I'm confident that the Linn table started life as nothing more than a gussied up AR table. The big difference between AR and Linn tables was that you didn't have to have a certified Linn guru keep your table "in bounce." Mere men were expected to set up their own tables.

If you still own a Linn table or Naim electronics, I apologize in advance for any transgressions or micro inequities.

[Bill Hart]

MEP- you come with a standard "trigger warning."

[mep]

My favorite cult was Heavens Gate in SD. You had to cut your balls off and were given a quarter to put into your pocket so you weren't considered a vagrant. And no, I'm not kidding. They all killed themselves so they could hitch a ride on a space ship that was waiting for them and hiding behind Haley's Comet.

[Gusf]

😂😂😂.

[Johnny Vinyl]

Speaking of cults.....anyone onto the Dead? LOL!

[mep]

Speaking of cults.....anyone onto the Dead? LOL!

Necrophiliacs?

[mep]

a double entendre if I ever saw one!

[MylesBAstor]

The Zombies?

[Gusf]

This has all gone down hill at an alarming rate!

[ashandger]

Glad you brought this up Myles as it's hugely important to me. Over the last 30 years have rejected several components due to this and a major reason why I have retained my Roksan turntable and arm and have had it upgraded to current specs. Music is just sooo engaging with it. I think Touraj focusses hugely on the timing qualities of his products. This is still a very important aspect for Martin Colloms as you will see from his reviews. A key reason why he loves his Magico S5s.

[MylesBAstor]

I for one never liked the term "PRAT." It was commonly used by semi-pretentious audiophiles who still think the sun rises and sets on Linn tables and Naim electronics, as well as their asses. I always looked at Linn lovers as a cult. I'm confident that the Linn table started life as nothing more than a gussied up AR table. The big difference between AR and Linn tables was that you didn't have to have a certified Linn guru keep your table "in bounce." Mere men were expected to set up their own tables.

If you still own a Linn table or Naim electronics, I apologize in advance for any transgressions or micro inequities.

Actually it seems there was more of a connection between Ariston and Linn turntables. 😎

https://groups.google.com/forum/m/#!msg/lecson-audio/q0xlE0SeHho/DvPjQHtq5OkJ

That said, why do some systems bore you to tears and others make one want to jump up and applaud!?!? I for one, based on my experience, think there's a rhythm issue. Accents, smearing, whatever.

[mep]

Your table/arm/cartridge and the rest of your system either keeps the beat or it doesn't. Just like what always distinguishes a great band is how well the drummer and bass player keep time together, it follows suit to our systems. The drummer is the main time keeper followed by the bass player. The drummer normally "counts" the band in to a song and lays down the beat for the rest of the musicians to follow. When Ringo's son Zak was touring with The Who, Pete Townsend was asked about Zak's drumming and Pete Townsend replied "the kid is always up my ass" meaning he was having to work to maintain the beat Zak was laying down. And by the way, I saw Zak in Louisville years ago when he was part of Ringo Star's All Star Band when John Entwistle was playing with them. Zak played so much like Keith Moon on The Who songs that it was scary.

[Gusf]

I saw Zak with The Who here in San Diego. Phenomenal show. If Pete was having issues they hid it well.

[Bill Hart]

I remember the first time I heard a Linn, with ARC electronics and probably Dahlquists, at Opus One in Pittsburgh in the mid-70s? Very lively, sparkle to the sound, punch, it was great. Never really got into the Linn thing. There was a huge Linn dealer in Brooklyn Heights back then. They did a little service for me on my stuff--Innovation--and there were a few people I'd probably remember from that store- but it was the whole only one pair of speaker in the room (a good thing- no sympathetic drain of energy from the movement of other drivers). more later.

[MylesBAstor]

Your table/arm/cartridge and the rest of your system either keeps the beat or it doesn't. Just like what always distinguishes a great band is how well the drummer and bass player keep time together, it follows suit to our systems. The drummer is the main time keeper followed by the bass player. The drummer normally "counts" the band in to a song and lays down the beat for the rest of the musicians to follow. When Ringo's son Zak was touring with The Who, Pete Townsend was asked about Zak's drumming and Pete Townsend replied "the kid is always up my ass" meaning he was having to work to maintain the beat Zak was laying down. And by the way, I saw Zak in Louisville years ago when he was part of Ringo Star's All Star Band when John Entwistle was playing with them. Zak played so much like Keith Moon on The Who songs that it was scary.

Funny thing is that early digital lacked PRAT.

[Bill Hart]

Funny thing is that early digital lacked PRAT.

It had BITE.

[Steve Lefkowicz]

I for one never liked the term "PRAT." It was commonly used by semi-pretentious audiophiles who still think the sun rises and sets on Linn tables and Naim electronics, as well as their asses. I always looked at Linn lovers as a cult. I'm confident that the Linn table started life as nothing more than a gussied up AR table. The big difference between AR and Linn tables was that you didn't have to have a certified Linn guru keep your table "in bounce." Mere men were expected to set up their own tables.

If you still own a Linn table or Naim electronics, I apologize in advance for any transgressions or micro inequities.

Apology accepted...

[mep]

Sorry Steve!

[Steve Lefkowicz]

That's okay, I've heard it all in the 30+ years I've owned the Linn. I remember going to a well regarded high end shop out here shortly after buying the Linn to see about upgrading my preamp. Same store I had bought my Acoustats from barely two years earlier, so they knew me . First thing the sales rep told me was until I replaced the Linn a better preamp wouldn't help much. Never stepped foot in that store again.

I learned a lot about trusting my own ears and reactions to gear during the shopping experience of buying that Linn, during the height of the 1980s "turntable wars" foisted upon the industry by The Absolute Sound. I still wonder why so many systems simply don't handle PRAT well at all, while others (including my low cost Linn fronted system) excel at it. It isn't just source related, I've heard otherwise good sounding amplifiers, that seem to get just about everything well enough, yet lack that PRAT capability and therefore come across as dull and uninteresting.

[Alrainbow]

A great really great topic Myles. I always heard forums for hesdpnes or personnel systems use prat amd a way to describe things. It took me a while to understand the term
while I don't ever consider myself and audio pro I can say I can tell good , bad and all in between. For me where it lacks is discrimination using words.
To put me Ina room with some others I hear what they do amd I can comment but lack the vocabulary of discreption

having said that I can say early digital lacked a few things and had others.
It had more details no doubt but there were prices to pay for it. Bite is one of the them the hall mark of bad pcm lol.
Only just a few years back when I bought my msb did I hear how it should be.
To correct someone who says it lacks rhythm I feel its not correct it's there. But it's not engaging it's not music it's sound.
I never felt caps had sound as an engineer how the bell could it
funny how untrue that is.
I have changed caps many times in my devices always an obvious change.

[Joe Pittman]

Myles, thanks for reminding me of the article by Martin Colloms (Pace, Rhythm, & Dynamics by Martin Colloms Stereophile Nov 24, 1992). It has been many years since I read this but many of the thoughts are still relevant today. I have thought about PRAT for many years. Following are excerpts from the article in quotes and a brief comment of mine in italics:

PRAT:
“Once you've learned that reproduced sound can impart that vital sense of music-making as an event, that the impression of an upbeat, involving drive can be reproduced again and again, you can't help but pursue this quality throughout your listening experience.”

Pace:
“there is a strong subjective element in the perception of the speed “
“weaknesses in the audio chain can give rise to errors “

Timing:
“The ear has an extraordinary ability to recognize playing which is not on or aligned to the beat”
“It is a fascinating aspect of audio reproduction that hi-fi components, individually or in concert, can damage the subjective impression of good timing and of tight, coherent musicianship.”
“Accurate portrayal of rhythm, though certainly very important for classical music, is absolutely vital for rock music. With its short presentation and simpler, more accessible structure, rock's rhythmic element is the foundation of listener involvement. Without that foot-tapping association, that invitation to dance, rock quickly descends to the boring”

Dynamics:
“Good dynamics are associated with an awareness of exciting lifelike contrasts between loud and soft sounds. Transients should be imbued with lifelike attack and sharpness, loud peaks really should sound explosively and dramatically loud. Those peaks should not be rounded, squashed, or compressed.”

Dynamic dilution:
“It's unfortunate that the subjective effect of all kinds of audio component errors is often a dilution of dynamic expression.“
“we are often too busy examining the texture of the bark to see what kind of forest we are walking in.”

Is beauty sufficient in itself?
“underlying animal force essential to a truly musical experience. Drama, surprise, and dance elements are essential to most music at almost every level of taste.”
“Coloration has been and remains a major flaw of loudspeakers”
“Yet if present to a mild degree, coloration may not by itself make or break a loudspeaker”
“many of those designs the goals of lifelike dynamics and good rhythm were foremost in the designers' minds, and that these goals would not be compromised in an attempt to deliver fashionably low coloration. “
“Which is the worse loudspeaker: the one that makes a German bassoon sound more like a French instrument, or the one that makes the bassoonist sound as if he hadn't had enough coffee that morning?---JA”
“The tonal purists felt more comfortable and less threatened by classical material, while the rhythm practitioners became more closely identified with modern rock and jazz”
“There is no good reason why neutral, transparent systems cannot also reproduce dynamic and rhythmic elements well“

The technology of rhythm is not in the textbook
“the over-engineering often seen in top-quality audio gear is generally scorned by the electronic engineering fraternity”
“for example, at present the only way of significantly advancing the sound quality of a top-grade power amplifier is to double the size of its power transformers, so be it.”

A loudspeaker example:
“heard to suffer from a lack of dynamics---not in the global compressive sense, but in the expressive, inner-dynamics sense. Likely causes are poor transient definition resulting from some combination of unwanted energy storage in the driver and enclosure system, and/or major flaws in the energy arriving at the listener”
“Attention paid to decay problems will also be helpful. In addition, problems in dynamics, rhythm, and timing are often tied to hysteresis effects in the mechanical suspensions and/or the cabinet acoustic loading.“
“Hysteresis in a speaker drive-unit is a phenomenon wherein recovery from a transient is artificially delayed due to some viscoelastic or memory effect”
“A neat example of bass rhythm differences is provided by the lovely little BBC-designed LS3/5a.”
“successfully linearizing the response, but at the significant expense of the speed and fluidity of bass lines”
“the potentially anomalous mechanical behavior of ferrofluid has to be balanced against its benefit in terms of reduced voice-coil heating.”
“UK critic James Michael Hughes has even recommended removing all of a speaker's filling material as a matter of course.”

Amplifiers & dynamics
“uncertainty or randomness in electrical behavior which can disturb the internal equilibrium of an electronic component. Such disturbances seem to relate well to subjective weaknesses in rhythm and dynamics.”
“One area increasingly familiar to amplifier designers is the effect of large transients on conventional amplifier power supplies. A fast crescendo momentarily drains the reservoir capacitors faster than they can be refilled by the charging diodes, causing the main voltage rails to sag.”
“The recovery characteristic of the main supply has a primitive time constant, but so do many other parts of the amplifier”
“Thus, following a big transient, both voltages and currents inside an amplifier are on the move, none directly related to each other or, more important, to the envelope of the music.”
“One such change examined was the size of the amplifier's power transformer. A clear correlation emerged between improved dynamics and rhythm”

It is the power supplies and the power systems that feed it that have a profound impact on your system in my option. It’s not just the large dynamics but also the very small micro-dynamics and everything in between. It is also the subtle interplay between micro and macro dynamics that create the illusion of reality and suspension of disbelief.

The future: “Rhythmic and dynamic qualities are fragile and easily diluted.

[Rust]

IMO much of this is related to the degree to which every component in the system stores and releases energy. If a component stores and releases energy mechanical, electrical or a combination of both and releases it out of phase thus superimposed on the signal it distorts the signal. Since transients are usually large amplitude, such a condition of sufficient amplitude could soften the transient which might be more noticeable as "timing".

The amplifier/dynamic speaker interaction would seem to be the most susceptible with large amounts of counter-EMF generated by the driver which could negatively interact with the amplifier creating short duration "standing waves" as indicated by severe phase angles when plotting the impedance characteristics of frequency vs. phase angle. Typically poorly designed crossovers contribute to this, or crossovers which have notch filters/zoebel networks to compensate for less than optimal drivers. Call it non-linear response, that is the output does not match the input.

Every component (meaning every part) in a system is capable of storing/releasing energy to one degree or another.

Capacitors are interesting in that they are used to block or transmit signal, or block DC. Capacitors are essentially non-linear devices, for practical purposes they charge/discharge in five time constants at approximately 77% of remaining capacity from no charge to full charge and the inverse to discharge resulting and a tilted "S" curve compared to a straight line, the hysteresis curve. A less than optimal capacitor selection for a given application would not fulfill its intended function well resulting in a distorted signal whatever that function was.

Much the same can be said of inductive devices. And at as power increases, thus increasing magnetic filed strength, speaker wire can become quite inductive. Especially as frequency increases which potentially increases the efficiency of magnetic coupling between the positive and negative legs, or more appropriately the send and return legs as the signal is NOT DC.

Then there is the amplifier/speaker interaction in particular dynamic drivers. They are capable of generating large amounts of counter-EMF which can certainly produce a non linear response, that is output does not match the signal input to the amplifier. In addition to non-linear response of the drivers themselves. I remember the early Thiels had hugely complicated crossovers to compensate for the drivers of the day and I was never impressed by those speakers.

As stated earlier every part, not just the larger "components" makes a difference to one degree or another. Which is one reason why past a certain point I'm a "good enough" sort of person. Literally cannot afford to head too far down the rabbit hole of chasing the "best" and the meds help it stay that way (said in my best Foghorn Leghorn voice ).

[MylesBAstor]

What about group delay?