Archive: The story of PRAT

By Michael Jones

October 2008 (originally appeared April 1993)

The cover of the April 1993 issue of AudioVideo (now AudioEnz)

Everything you've always needed to know about pace, rhythm and timing

When I was a fledgling audiophile, a number of years back, I used to take some of my favourite albums around to play on the stereo systems of other audiophiles. Much to my surprise many of my favourite rock albums sounded, well… boring and unexciting on some of these systems.

All of these stereo systems were more expensive than mine, and the owners much more experienced in the ways of hi-fi than I was. So when they told me that their hi-fi's were merely showing my favourite albums in their true light, I had no option to believe them.

But somehow I knew that this was not right. Although I didn't realise it at the time, the answer was given to me by Chris Murphy (now the Nairn Audio importer). Chris used to rave on to me about how through some hi-fi equipment “the band was playing together”, whereas the band didn't play together on other hi-fi. I knew that Chris was nuts. After all, this didn't make any sense. Time has modified my view. (And don't worry Chris. I still think you're nuts, though now in different ways…)

As time went on, I gradually became aware that different hi-fi systems could alter the portrayal of musicianship. Through some systems, the band appeared to be playing faster, or more uptempo. Instrumental lines that appeared to flounder could suddenly make sense.

It's been fascinating to watch the noted UK hi-fi reviewer Martin Colloms (Hi-Fi News) explore the same territory over the past couple of years. Colloms referred to "pace, rhythm and timing", which one Hi-Fi News reader cleverly dubbed "PRAT". So PRAT is how I now label these phenomena.

Before delving any further into the subject of PRAT, it would be useful to define a few terms.

Pace

Pace refers to the apparent musical tempo. I use the word "apparent" with care, for if a metronome was used, the tempo would remain the same no matter the hi-fi. Yet in different hi-fi systems, the group of musicians can sound as if the ensemble are playing at differing speeds. In some hi-fi systems, it can sound as if the musicians are playing at a slower tempo or pace – downbeat instead of upbeat.

This appears to correlate with impaired interest or involvement in the music by listeners. Interestingly enough, in my experience hi-fi equipment never makes music sound as if the tempo is too fast. The effect of hi-fi equipment on tempo, if any, seems to be only to reduce the pace or tempo of music.

Rhythm

Much music in our culture is built upon a rhythmic base. And yes, hi-fi components can affect our perception of the rhythmical lines in music. Way back in the December 1990 issue I wrote about the Creek 4140 amplifier’s ability to unravel rhythmical lines.

Although through a number of other competing amplifiers the piano sounded tonally more accurate, through the Creek the musical lines, the playing with time that a good composer and musician can bring, were laid bare.

In comparing CD players and amplifiers over the years, I have been perplexed at how there was more than just "sound"; that through some products the music the music made sense.

A few years ago a friend was building an amplifier. Often he would bring the latest version, along with an amplifier at the previous stage, over to compare. One of my friends favourite albums was Peter Gabriel's So. At one stage of the amplifier modifications, the Fairlight bass doodlings on one track (Sledgehammer from memory) suddenly stopped being merely tonal colouring, and became part of the rhythmic structure of the music!

Timing

If pace referred to the musical ensemble as a whole, timing refers to the individual musical parts.

"If the musicians are pleasing us we often say they were 'hot', or 'the band were smokin'!", wrote jazz reviewer John Paul in the February 1993 issue. A large part of this is down to the synchronisation of the musicians or, as it is often described in the classical world, their ensemble.

A group of musicians that are playing well tend to lock into each other, creating music that is more than the sum of its parts. This is as apparent in rock music, where the band can ride a groove, as it is with a string quartet.

Yet some hi-fi equipment can dilute this musical energy. Sometimes the lack of timing can be frequency dependent, as if the drummer was playing the cymbals out of synchronisation with the rest of the drum kit (or band, for that matter).

At its worst, it can be as bad as one system I heard playing the Oscar Petersen Trio's album We Get Requests. On this hi-fi system, it sounded as if there were three separate recordings: each member sounded as if they were playing vaguely the same tune, at vaguely the same time. But they weren't playing together.

The audiophile dilemma

Many audiophiles have trouble getting to grips with these concepts. I know I did, until I realised that PRAT was describing how music exists in reality. The reason many audiophiles have trouble grasping these concepts, I believe, is largely due to the training' they receive. Reading hi-fi magazines, talking to audiophiles and conversing with the staff in many hi-fi stores, reinforces that hi-fi is all about the reproduction of tone and of space.

To make things worse, many of the products that perform well in PRAT parameters have often performed less than wonderfully in the traditional hi-fi checklists, sometimes sounding quite strident.

It has recently been put to me that the pace, rhythm and timing that some hi-fi components reproduce is because they often aren't wonderful tonally. In other words, that PRAT is a distortion. So far, no one has been able to explain to me how this 'distortion' manages to find its way into live music performed by real people.

Listening for PRAT

Back in the early '80s, Linn's Ivor Tiefenbrun suggested that the ability to tap your feet to the music, and to hum and sing along with the tune, were among the most important attributes to listen for when buying hi-fi. As often happened with Tiefenbrun's prunouncements, these comments were widely dismissed by many in the audio industry. Even though Tiefenbrun was right.

Although inexpertly put, Tiefenbrun's suggestions basically came down to this: react to music played on a hi-fi the same way you would to live performers. Instead of straining to hear the hi-fi parameters that is the approach of most audiophiles to hi-fi, react to the music on an emotional level. I now find that pace, rhythm and timing have become necessary – but not sufficient – conditions for me to enjoy my music through hi-fi equipment.

"Music, I feel, must be emotional first and intellectual second," said composer Maurice Ravel. So don't over-intellectualise hi-fi. Enjoy it instead.