Native High-Resolution versus Red Book Standard Audio: A Perceptual Discrimination Survey


Mark (Dr. AIX) Waldrep's abstract for a paper he's submitted to the Audio Engineering Society. I've listened to the files and could not hear a difference.

"The perceptibility of high-resolution versus CD standard audio has been the subject of research and debate since the introduction of hi-res audio distribution formats almost twenty years ago. The author conducted a large scale survey to determine whether experienced listeners could differentiate between a diverse set of twenty native high-resolution PCM stereo recordings and downconversions of the same masters at CD spec, 44.1 kHz/16-bits fidelity – Red Book Audio.

"Participants were encouraged to audition the files using their own systems, which ranged from modest, headphone-based personal setups to audiophile quality rooms costing in excess of $50,000 to professional studio environments. They were not allowed to use analytical tools or other non-listening means to assist in their observations. Over 450 responses were received from professional audio engineers, experienced audiophiles, casual music enthusiasts, and novices aged eleven to eighty years.

"The online survey submissions show that high-resolution audio was undetectable by a substantial majority of the respondents regardless of experience level, equipment cost, or process with almost 25% choosing “No Choice.” However, some evidence suggests specific genres and recordings produced marginally higher positives."
zyxzyx
Post removed 
Post removed 
angelwars: " Waldrep's main gripe is old analogue recordings being sold as 'Hi Res' when they never were in the first place - not that there is anything wrong with old analogue or digital recordings made at CD spec but it's misleading to say they are Hi Res."

Hello angelwars,

     I wasn't aware  that Waldrep now understands that the provenance of the original master recording technology dictates the optimum quality level of the masters, as well as any subsequent copies made from them.  Good for him and I stand corrected.

Thanks,
   Tim  

     
Tim,

No you are mistaken, Waldrep has used his own 96/24 recordings not analogue stuff and created 44.1/16 versions as well for people to download and compare. He is trusting that no-one is using analysis tools to view the files to cheat. For the record I downloaded and compared and cannot tell any difference. For years he was an advocate for Hi res as playback but has completely changed his opinion.

Waldrep's main gripe is old analogue recordings being sold as 'Hi Res' when they never were in the first place - not that there is anything wrong with old analogue or digital recordings made at CD spec but it's misleading to say they are Hi Res.
   " The author conducted a large scale survey to determine whether experienced listeners could differentiate between a diverse set of twenty native high-resolution PCM stereo recordings and downconversions of the same masters at CD spec, 44.1 kHz/16-bits fidelity – Red Book Audio."

Hello zyxzyx,

     Your sentence above is very vague at best.  However, I read it as meaning people couldn't tell a difference between a diverse set of twenty master tapes, typically recorded and mixed on high speed analog reel to reel tape recorders, transferred to high-resolution PCM digital stereo recordings and the same masters transferred to 16 bit/44.1kHz Red Book digital stereo recordings.
     I don't understand why this would surprise anyone, let alone why Dr. AIX would bother to conduct a controlled, large scale scientific survey of individuals' perceptions and submit a paper to the Audio Engineering Society on the subject. 
     The very obvious reason you and other individuals had difficulty hearing a difference between these formats was because you were being asked to compare a series of virtually exact digital copies of the original analog reel to reel master tapes, stored and played back as hi-res digital PCM stereo recordings, to another series of virtually exact digital copies of the original reel to reel master tapes, stored and played back as hi-res digital Red Book stereo recordings.  No legitimate differences were noted because none exist between these identical copies.
     Red Book CDs are technically capable of being a high resolution format but are generally not considered hi-res due to the reality that many suffer from poor recording/mixing choices, such as uniformly increasing the levels across the entire audio spectrum in order to sound louder overall when played back, referred to as the 'loudness wars', that has the desired effect but also flattens the natural dynamics of recorded CD music in the process.
     The quality and technical capabilities of the master recording equipment technology and format along with the skill and experience levels of the recording engineer are the primary factors that determine the quality level of the recorded master. It's a further fact that the quality level of the master recording itself, no matter what technology and format was utilized in its creation, represents its 'provenance', which can be considered the history and quality level of the recording technology originally used to capture and store the music.   
     Once it's been recorded, mixed, engineered and stored on a recording storage medium, the master recording has reached the pinnacle of its quality level that's dictated by its provenance.  Any master copies made and subsequent transfers to other playback formats typically leads to some signal degradation of the master as well as the copy and cannot lead to any quality improvements. 
     The only exception to this recording and transfer reality is direct to hi-res digital, which not only is capable of being a high quality master recording medium but an infinite quantity of exact copies can be made from it with zero degradation of the master and the copy. , The reality is that any transfer from a higher quality recording and storage format, such as high speed reel to reel, to a lower quality playback format, such as LP, will restrict the storage and playback quality level to the lower quality format's quality capacities.
       However, it's also true that any transfer from a higher quality recording and storage format, such as high speed reel to reel, to an equally or higher quality recording and storage format, such as high resolution digital, will not be restrictive at all and has the capacity to make an identical copy of the master tape.  The transfer of reel to reel master tapes , which are usually older and tend to degrade over time due to the physics of the tape medium itself,  to hi-res digital files is also an effective means to accurately preserve the content of these older, delicate reel to reel master tapes indefinitely.
         I believe a better survey would entail having a group of individuals listen to a live music session in a small studio or club venue while it's being simultaneously recorded direct to hi-res digital at both 24 bit /96kHz or higher and recorded to the more traditional method of high speed reel to reel tape.  These recordings would then be played back to the group and asked for their perceptions on quality comparisons.
     Based on my personal experience, there is a significant and obvious increase in sound quality performance on music recorded direct to hi-res digital when compared to the sq performance of most, but not all, music recorded on high speed tape and transferred to CDs.

Tim 
          ,