I'm not certain, but I think it is an acronym for Pace, Rhythm And Timing.
23 responses Add your response
Pace, Rhythm and timing
I have heard it described as the ability of a system to make you want to tap your foot to the music. This does make sense to me as I've heard the same recording on different systems where one system had me struggling to listen and the other had me tapping my foot in pure musical enjoyment.
Some components appear to have better PRAT than others because of the aspect of the note that you are hearing. As a drummer, I time the music on the edge of the notes. And I guarantee that you hear/assess PRAT in the same way.
If a player opens up the middle of the note more than another, it may sound fantastic for vocals, but appear to have less PRAT--or even to sound too laid back--than another player that accentuates more the edge of the tone. This is often the reason that one player has you tapping your foot to the music, and another not. Or that you might conclude that a particular component is great for rock but not for jazz.
My Sony XA7ES, for example, appeared to have much better PRAT than our Audio Aero Prima, simply because it had better definition in the tones where we listen for PRAT. It did not play any faster, though it actually might appear to be doing so. So as Pbb suggests, it may be a subjectivist fiction. However, the term does help one audiophile to communicate to another on a specific arrangement of the sound one can expect to hear from a particular component.
Hope that helps,
PRaT is the kind of comedic "trip and fall" that Chevy Chase excels at. But seriously, Boa2's comments are very interesting and might explain why I prefer listening to, say, Mahler and Strauss songs through my tube CD player while appreciating foot-tapable stuff better when it's played on a good SS system.
Pbb...while I agree that PRaT is very subjective, I don't believe it is fiction. When a large group of people can find agreement on an experience consistently, even if not quantitatively confirmed, it is not fiction.
Ask any person what "quality" or "complexity" is. I've read that even people in primitive cultures can find agreement on these terms, without similar backgrounds. How do quantitatively describe them?
Thus...you're right, but so is everybody else.
If you could imagine that music has vowels (air, holography) and consonants (detail, impact), a tendency to accentuate the consonants would translate to a component having better PRaT. As a representation of timing, it can be very deceptive, because as the music opens up it appears to slow down.
No joke, mlauner, Naim has PRaT down VERY well.
All the best,
I too think of hifi terms with music as a reference. Music is a magical thing. When musicians are listening and playing with each other you'll know it. When they're not in sync, you'll know it. It's unmistakeable. To me, the ability for musicians to gell and play tightly together is PRaT. If a player is constantly early or late, the performance starts falling apart. In music reproduction there are obviously more variables. The musicians first have to get it right before any reproduction system can reproduce it. But great performances are great performances because they get everything right. When it's reproduced in a music system, everything has to be just as spot on at least in terms of rhythm. When it's not, it doesn't feel as "right" and you'll invariably be moved less.
Objectively speaking, PRaT is directly related to the speed of a system's response and is the continuously relative delay between the information being read from the source and the tones being reproduced from the driver. The design factors that will have perhaps the largest impact on this would be the quality of the power supply in the amplifiers and the speed of the materials used in the driver material.
There are lots of opinions about this out there, and if you google "flat earth audio" you will undoubtedly find a link to the flat earth forums where this has been debated into the ground.
Legend has it that the foot-tapping description was attributed to Linn, who encouraged their dealers to tap their feet when demoing Linn systems and not tap their foot with competitors equipment to demonstrate the rhythmical superiority.
Now, to add a bass player's perspective (adding to the drummer's) the PRaT of a system just means that large transient attacks of a bass are not softened by a slow amplifier and the punch of the instrument is properly presented to the listener. My current bass amp is small by most standards but even then a home hi-fi would have a considerable task to replicate the punch of a 400W dedicated amplifier and two 12" long voice coil drivers. Systems with PRaT do try, and some do it very well.
I've owned systems from a British manufacturer known for PRaT and found that it got the PRaT factor right in many ways, but the overall balance of the music gets lost in the process. Speed at all costs, if you will. I've moved on to a newer tube-based design from Audio Research that strikes a better balance.
In the end, this is simply another audiophile discussion point. There are a million and one ways to tell other people how your system is different than everything else on the market, and PRaT is popular with British audio fans to do just that.
'PRAT' is an abbreviation of a long-winded way of saying 'rhythm'. How could concepts of pace and timing not be included in the plain idea of rhythm?
I refer to my OED online:
"Rhythm: 'That feature of musical composition which depends on the systematic grouping of notes according to their duration. b. Kind of structure as determined by the arrangement of such groups.'