The discussion of high-resolution terminology requires a common set of terms, assumptions and basic concepts. It should really mean something when you say something is high-resolution or ultra high-resolution (I saw that one yesterday associated with a release from Reference Recordings…a PCM recording released at 176.4 kHz/24-bits).
Over the course of 10 years or so, I’ve talked about high-resolution terminology and definitions with hundreds of people from audio engineers, to audiophiles and individuals from the consumer electronics companies. Thus far, I’ve been unable to get a consensus even among professional audio engineers. Unlike the working groups that found common ground on defining the various formats in video delivery (standard definition, high-definition and now ultra high-definition), music and audio engineers and other interested parties have not been able to establish meaningful and absolute definitions. This is a problem.
I believe that the terminology has to be universal, convenient, simple and communicate the essential quality associated with a particular recording. Yesterday, I dismissed the “Studio Master” term embraced by some as being meaningless. Don’t we want the descriptive term or a logo to mean something qualitatively? I think so. And the term “Studio Master” doesn’t do that…it is more closely aligned with the provenance of a given recording; Unless you know the history of audio and the equipment and procedures that were employed in the production of individual projects, you can’t know what level of quality to expect with a generic term like “Studio Master”. There is value to this descriptive/historical designation…I’ll come back to it tomorrow.
Ideally, we want a term that helps us to identify the quality of the experience that we’re likely to have when listening to a track, not some reference to the output of the studio that mastered the recording. Additionally, we can’t rely on the specification numbers or the format to have any meaning with regards to fidelity. Just because something is delivered in a 384 kHz/32-bit data bucket doesn’t mean that it meets the potential of a PCM recording of those specifications.
So I start from a different place than most advocates for High-Resolution Audio. At the present time I believe there should be three quality designations and within them categories for both source and delivery formats and specifications. Here are the three major categories:
High-Definition or High-Resolution – Recording and playback systems that have the potential to meet of exceed the capabilities of natural human hearing. New recordings done at 96 kHz/24-bits or better with the intent to maximize fidelity.
Standard-Definition or Standard Resolution – Recording and playback systems that have the potential to capture and reproduce a frequency range of 20 kHz and 60-90 dB of signal to noise ratio. Think analog tape, vinyl LPs and compact discs.
Low-Definition or Low Resolution – Recording and playback systems that have the potential to capture and reproduce a frequency range of 15-18 kHz and 20-40 dB of signal to noise ratio. Here we’ll have 128 kbps MP3, HD-Radio, AAC and other heavily compressed (data compression) formats.
I’m being very careful to describe the “potential” of each level…because it is possible to use an HD-Audio container to deliver a low-definition/resolution recording. In fact, it happens all the time…most of the commercial recordings that are made available through iTunes fall into this category.
An analogy would be the quality of a family 8mm movie shot back in the late 50s after it has been telecined to an ultra HD-Video format container. The quality of the source video is still that of the 50’s era film.
We have to maintain the distinction between the potential fidelity of the source and the potential of the delivery format. It makes little sense to transfer a DSD 64 recording will all of its inherent “out of band” noise to a 192 kHz/24-bit PCM file…although there are plenty of vendors doing exactly that.
To be continued…