What does 'Fast mean?

John (jafox):
Of course they all mean the same thing. I have never met anyone who has been able to describe any meaningful differences between the constituents of this acronym, nor do I expect to. I use it simply because it is recognizable and seems to have found its way into the audio argot, not because I defend its origins, semantics or anything else. Perhaps I should just use "fast" or "well paced" in the future, because that is all I mean.

Chris

Newmanoc: actually I think you're right in that "pratt" probably originated with Naim when the two Cos were working closely together. THEN the Linn marketing/sales people did quite a lot of use of that with their dealers. It;s gone out of fashion now I suppose...

Loosely defined, the erstwhile "pratt" meant a "crispy" sound in the all important 100-10kHz region with close focus on 300-~6kHz: the point was to get FR and phase as good as possible in that range (think of the old LP12).

Much of the music listened to & used for auditioning at the time was rythmic (4/4, 8/4 etc) with vocals. Sooo, if you focused on the main part of the frequency spectrum rather than the extensions -- i.e. your 300Hz blended in well with the 5kHz say -- you had this lively, pleasant sound. I.e. "foot-tapping" sound as the good Mr Tiefenbrun used to say.
Focus on the range & its slight prominence also meant that with speakers reasonably (but not painstakingly) set up, the "springy" effect was still there.
Voila in reductionist and simplified form. Linn & Naim can offer a much more precise & sophisticated explanation, of course. Cheers

I think the point here is harmonic reproduction - not the speed of light or the switching speed of devices.

Reproducing harmonics means reproducing music. The question is whether the harmonics we hear are from the media or the electronics. The electronics can add harmonics (distortion) or remove them (low bandwidth and/or stability).

Problem is that there is no reference point - hence all the debates found in audio forums, including this one.

Arthur

Gregm:
Thank you - your post was very informative and very helpful. Your description of systems designed for "PRaT" slightly emphasizing frequencies across the core of the audible frequency range makes sense to me. This is perhaps what people mean when they talk about "smearing" of sound from these systems (a term that strikes me as a little harsh). It does seem that systems that have this "crispy" sound do so at the cost of sacrificing things that others value more, such as the frequency extensions and low level detail (if I understand this latter term correctly). I suppose what to one man sounds like musical coherence to another sounds like sonic oversimplification. I think this "PRaTy" emphasis sounds less “audiophile” and more like live music. But my ears are not everyone’s ears, nor my tastes their tastes. Thanks again for your helpful post.