Hi-Rez - Another Myth Exploded!

[gregorio]

You can't just take dynamic range specs etc and not look at the entire picture. There's always going to be some discussion about what is audible and not but at 16/44, the amount of distorion or non linearity near the noise floor is quite high regardless of dither and effectively limits things. 16/44 has always sounded a bit dead or lacked that ease or sustain until masked by the next louder sound type of character I get from good analog or 24/96. I don't get more music going beyond 24/96. I have always found up or downsampling in exact multiples to be better and I use after market dither in Wavelab to do it.

Not sure where you picked this up from. There are a couple of problems with what you are stating. First of all, yes there is some non-linearity near the noise floor (in the Least Significant Bits, LSBs). But to then say "regardless of dither" is completely incorrect. The whole reason why dither was invented and why it exists is specifically to remove the non-linearity in the LSBs. I said I'm not sure where you picked your assertion up from because dither is hardly some new development, dither has been a required feature of digital audio since the 1980's. Dither works by randomising any quantisation errors, effectively converting them into white noise. What you end up with in the LSBs is perfect linearity plus some noise, it is this noise which defines the digital noise floor. More recent developments (about 12 years ago) was the introduction of noise-shaped dither. This not only eliminates quantisation error (non-linearities) but moves much of the resultant noise to the least sensitive areas of the hearing spectrum. This results in CDs being able to provide a perceived dynamic range of roughly 120dB (equivalent to 20bit). In other words, not only is "non-linearity near the noise floor" not "quite high", it is actually non-existent! So obviously, something which doesn't exist cannot "limit things".

There can be as much discussion as you like, the fact is that a correctly noise-shaped dithered 16bit CD is going to have a digital noise floor at least 1,000 times lower than the noise floor of the music recording stored on it.

"You can't just take dynamic range specs etc and not look at the entire picture." - I think you need to explain this, the entire picture when it comes to bit depth is the dynamic range (or amplitude to be more precise), what else do you think is there?

16/44 (and 24/96) has way more accuracy, HF linearity and not to mention dynamic range than any analogue recording you may own. If you are hearing a lack of ease or sustain at 16/44 but the same type of sound character from both analogue and 24/96 there can only be 3 possible explanations: 1. All your 16/44 music files are incredibly badly mastered or 2. Your DAC has a fault or serious design flaw when decoding 16/44 files or 3. Placebo Effect.

G

 

[gregorio]

I think they only just managed a significant result in DBT 
 
Something I wonder about from time to time regarding double-blind testing, since hearing is a psychoacoustic phenomenon, is what questions are being asked, and what questions should be asked.  More specifically, are folks being asked questions like "Is this one the same or different from the last one?", or questions more like "Which of these do you like better, or do you feel there's no difference?"  The first sort of question I can see producing some pressure to get the answer right, perhaps not the best frame of mind in which to evaluate music.  I wonder if the second type of question would produce results that differed at all significantly (in either direction - being able to discriminate or not being able to) from the results produced by the first.
 
An interesting experiment for some grad student somewhere to perform, mebbe (and for others to try to replicate). 

As I understand it, most DBTs simply request that the listener reliably distinguishes one piece of equipment from another - the question is simply "Which is which?" or "Which do you prefer?".
Indeed, in some tests people profess to still hear "impossible" differences - right up until their scores are added.

In principle and in general, I'd agree with you. I think though when it comes to highly experienced engineers, who spend their careers subjectively and objectively analysing sound quality, that we should ask for a little more detail than simply "which do you prefer". Beyond stating in the article that it was a DBT no details were given as to the precise test conditions, it was an article after all rather than a scientific paper. The results and impressions were discussed by the engineers and author after the DBT and this discussion was the main content of the article.

In the article, the Prism, Apogee and 192HD were not specifically identified. They all correctly identified the 192 (old version) as the weakest but all agreed that the difference between the 192 and the other three was surprising small, relative to the expected difference (bare in mind the 192 was released in 2002 and the other three in the last year or two). They agreed that the "three" were virtually identical, the differences being on the edge of perception.

G

 

[gregorio]

Double post - Deleted

 

[anetode]

 
Quote:

That would be an incorrect conclusion.    Rather, what you find "cynical," I would characterize as paying attention to Santayana.  We don't want to doom ourselves to repeat the history of "perfect sound forever" by ignoring what happened then.  What happened?  It seems to me we thought our "very good approximation" of Nyquist-Shannon was so close that for practical audio purposes we'd achieved perfect reconstruction, or as near as it was possible to get.  We thought so strongly enough that many folks were willing at first to ignore audible evidence.  Later of course the audible became measurable (e.g., jitter, "brickwall" filtering, and resultant distortion in the audio band).
 
Now we certainly take more care with jitter and filtering, and we've given ourselves a lot more headroom.  If a model should be as simple as possible but no more, is it now time to say we've got everything important in our model at 96kHz, and any difference between that and 192kHz cannot be audible and therefore cannot be important enough to include?  As I said above, some people think so, some don't, and I don't know for sure.
 

Well you do have the advantage of perspective over me, I wasn't around for the early days of digital and didn't even hear a CD until I moved to the US in 93 at age 10. However taking into consideration the listening study which found no statistical evidence for audible differences between CD & high rez, I'd say that perfect sound forever wasn't that outrageous of a claim (though more like "perfect sound forever" with an *). 16/44 isn't ideal but I gather that was ambitious given that time's equipment.
 
The current arguments about going beyond 24/96 are much easier to dispel and analogizing everything to the initial uncertainty over the very introduction of digital audio isn't entirely honest. There's a difference between skepticism and ignoring evidence (and I don't mean anecdotal evidence or marketing).
 
Quote:

Originally Posted by judmarc /img/forum/go_quote.gif
 
I'm quite curious about the subject and would much appreciate recommendations/citations if you have them.

 
I found the "Art of Digital Audio" by John Watkinson to be a very good introduction, having found a cheap copy of the 1984 first edition. Looking over amazon's reviews it appears that the later editions are still behind the curve on more modern technology, but I can speak from experience that reading Lavry's paper before, and re-reading it after Watkinson's book, I now have a much greater appreciation of it.

 

[gregorio]

^ There are two potential dangers:

1. My OP suggests a logical conclusion some time in the future (not far away) when we arrive at a "perfect sound forever" (perfect linearity within the human hearing spectrum) as far as digital conversion is concerned. The perceived danger (mentioned by judmarc) is that this would stifle further development of digital audio. Maybe this is true but I don't see a problem with this, once we really have achieved perfect linearity according to Nyquist-Shannon. When we reach this point, there are still many other areas of audio recording, manipulation and reproduction to be addressed. And the subjective perfection of music is an ever changing goal post which will probably never be achieved.

2. The greater danger in my opinion and the route we appear to be taking is the idea that perfect sound (linearity) can never be reached. This idea is a marketing idea and is contrary to the scientific facts. The danger is that we continue development ad infinitum, regardless of perfect linearity. 192kS/s is proven to be less linear than 96kS/s (there is no scientific evidence to the contrary) but marketing is succeeding in convincing many consumers of the opposite. When I say marketing I don't just mean adverts saying 192kS/s is "Reference Quality" and implying 192k is better. I mean a much more subtle effect, say if a marketing department dictates to the engineering department to use poor quality 96k filters and concentrate development at 192k.

The simple fact is that 16/44 perfectly encompasses everything any human can hear. Limitations imposed by current technology means we need to go a little higher to keep filter artefacts well away from the hearing spectrum, 16/60 would solve all limitations (for playback and 24/60 for recording and mixing), current and future. Unfortunately, past marketing decisions mean that this perfect format does not even exist! So we have to go to the nearest format which does exist, 24/96 but even this format represents a compromise (albeit a small and inaudible one).

G

 

[Megaohmz]

Sounds to me that to be able to take advantage of the 192 bit rate, a more powerful computer processor is needed. It makes sense that 192 would have more detail theoretically. I guess we need to wait for the technology to improve.  

 

[gregorio]

Sounds to me that to be able to take advantage of the 192 bit rate, a more powerful computer processor is needed. It makes sense that 192 would have more detail theoretically. I guess we need to wait for the technology to improve.  

Then you have completely misunderstood the OP. Try reading this post which will help you understand how digital audio works.

G

 

[Chris J]

I've been reading this post for the past couple of days.
Gregorio:
From what I know about audiophile loudspeakers and the rooms audiophiles listen to them in, I can't help but wonder if when we say we don't like a recording because it is too analytical or detailed or revealing what we really mean is we don't like how it sounds in our listening room with our loudspeakers? Yes?
Since we cannot create world class mastering quality listening rooms at home (does anyone actually know anyone with a reference class listening room?) then we are stuck with listening to recordings with all the bad room interaction we get from our listening rooms.
Now I realize that this is the Head Fi web site, however, I suspect the recording/mixing/mastering process is optimized for loudspeaker reproduction, not headphone reproduction. And if your headhones have peaks and valleys throughout the treble region??? Then you might not like an accurate recording.

 

[Chris J]

The dry signal isn't clipped.  It's a dirac pulse.
Also, this VST is from Lexicon lol.  I paid about 1.5k for it.
 
Oh!  I see what happened!  The problem lies in what the oversampling algorithm I used did to the pulse!
 
I fixed it.  They now have the same pulse!
 
http://www.pelpix.info/native.flac
http://www.pelpix.info/oversampled.flac
 
They now sound exactly the same except for the high-end roll-off!

Please keep in mind that Digital Reverb is just another type of DSP, and basically needs the same care in design and implementation that any other form of digital signal processing needs whether it be EQ or compression or mixing, etc.

 

[gregorio]

I've been reading this post for the past couple of days.
Gregorio:
From what I know about audiophile loudspeakers and the rooms audiophiles listen to them in, I can't help but wonder if when we say we don't like a recording because it is too analytical or detailed or revealing what we really mean is we don't like how it sounds in our listening room with our loudspeakers? Yes?
Since we cannot create world class mastering quality listening rooms at home (does anyone actually know anyone with a reference class listening room?) then we are stuck with listening to recordings with all the bad room interaction we get from our listening rooms.
Now I realize that this is the Head Fi web site, however, I suspect the recording/mixing/mastering process is optimized for loudspeaker reproduction, not headphone reproduction. And if your headhones have peaks and valleys throughout the treble region??? Then you might not like an accurate recording.

Absolutely, I agree entirely with your basic premise. However, there are a couple of facts regarding the mastering process missing from your conclusions. As mastering is the final stage of quality control, mastering rooms need to be as accurate and revealing as possible to allow for the identification (and correction) of any problems. However, most good mastering engineers are also considering who the target audience is, the musical genre and what the distribution format will be. Mastering engineers take into account that the finished product is not going to be heard in a mastering studio but in a car, in a sitting room or from an iPod as an MP3. A mastering engineer will vary their techniques and the colouration of the finished product in an attempt to satisfy both the clients' wishes and the consumers' perception. Obviously this requires a great deal of generalisation, compromises and extraordinary experience, knowledge and skill from the mastering engineer. Which is why top mastering engineers are very rare, very well paid and the most respected of audio professionals. Sometimes though, the compromises are too great and a mastering engineer may be required (or may suggest) to make different masters for different uses.

So where does this leave us, the audiophile. If what I'm saying is true, then even a mastering room isn't the best place to listen to a finished product. To be honest, I don't really have an answer! Without knowing what the mastering engineer has done, what colouration or compromises (if any) have been made, it is impossible for me to have a perfect reference point of what the recording should sound like and what I should do to get closer to that reference point. To make it even more difficult, there are relatively few fixed "rules" of mastering. Give the same pre-master to 2 different mastering engineers and the result will be two slightly different sounding masters. Mastering is a mixture of science and art and of course we must also recognise that a lot of mastering is done on a budget by those without much skill and without top class facilities. IMO, there is no perfect solution to how to listen to a recording and it's really up to the individual consumer to decide. Although marketing hype of equipment and audiophile misinformation often makes this decision next to impossible. Although in general (IE. not always) you are correct that speakers are going to get us closer to the intentions of the recording than cans. My own personal philosophy is to use as linear (transparent/neutral) system as I can and to make allowances in what I hear, according to my guesstimation of the mastering engineer's intention, based on the genre and target audience. For example, I know that a particular commercial pop genre is usually aiming to create energy, so if I listen to that genre on a neutral system I might expect to hear more distortion, compression and mid frequency content than if I'm listening to a gentle sonata.

You have raised a vitally important point though, as production and mastering has (almost) infinitely more impact on our perception of the music we are listening to than what DAC, source or cables we are using and this point is often completely ignored by many audiophiles. I understand why though, despite assertions to the contrary, there is no perfect listening environment or equipment (as explained above). In other words, this is a complex problem with no simple or single correct answer. For example, although I personally wouldn't choose to ever use a tube amp, I can see a certain logic if someone's genre of choice is say heavy metal but I would question the logic of using a tube for listening to high quality orchestral recordings. So, we have no specific, simple correct answer as to whether everyone should or should not use a tube. I think that the audiophile community would benefit greatly from a little more appreciation of the general principles of mastering.

G

 

[LFF]

Quote:

Absolutely, I agree entirely with your basic premise. However, there are a couple of facts regarding the mastering process missing from your conclusions. As mastering is the final stage of quality control, mastering rooms need to be as accurate and revealing as possible to allow for the identification (and correction) of any problems. However, most good mastering engineers are also considering who the target audience is, the musical genre and what the distribution format will be. Mastering engineers take into account that the finished product is not going to be heard in a mastering studio but in a car, in a sitting room or from an iPod as an MP3. A mastering engineer will vary their techniques and the colouration of the finished product in an attempt to satisfy both the clients' wishes and the consumers' perception. Obviously this requires a great deal of generalisation, compromises and extraordinary experience, knowledge and skill from the mastering engineer. Which is why top mastering engineers are very rare, very well paid and the most respected of audio professionals. Sometimes though, the compromises are too great and a mastering engineer may be required (or may suggest) to make different masters for different uses.

So where does this leave us, the audiophile. If what I'm saying is true, then even a mastering room isn't the best place to listen to a finished product. To be honest, I don't really have an answer! Without knowing what the mastering engineer has done, what colouration or compromises (if any) have been made, it is impossible for me to have a perfect reference point of what the recording should sound like and what I should do to get closer to that reference point. To make it even more difficult, there are relatively few fixed "rules" of mastering. Give the same pre-master to 2 different mastering engineers and the result will be two slightly different sounding masters. Mastering is a mixture of science and art and of course we must also recognise that a lot of mastering is done on a budget by those without much skill and without top class facilities. IMO, there is no perfect solution to how to listen to a recording and it's really up to the individual consumer to decide. Although marketing hype of equipment and audiophile misinformation often makes this decision next to impossible. Although in general (IE. not always) you are correct that speakers are going to get us closer to the intentions of the recording than cans. My own personal philosophy is to use as linear (transparent/neutral) system as I can and to make allowances in what I hear, according to my guesstimation of the mastering engineer's intention, based on the genre and target audience. For example, I know that a particular commercial pop genre is usually aiming to create energy, so if I listen to that genre on a neutral system I might expect to hear more distortion, compression and mid frequency content than if I'm listening to a gentle sonata.

You have raised a vitally important point though, as production and mastering has (almost) infinitely more impact on our perception of the music we are listening to than what DAC, source or cables we are using and this point is often completely ignored by many audiophiles. I understand why though, despite assertions to the contrary, there is no perfect listening environment or equipment (as explained above). In other words, this is a complex problem with no simple or single correct answer. For example, although I personally wouldn't choose to ever use a tube amp, I can see a certain logic if someone's genre of choice is say heavy metal but I would question the logic of using a tube for listening to high quality orchestral recordings. So, we have no specific, simple correct answer as to whether everyone should or should not use a tube. I think that the audiophile community would benefit greatly from a little more appreciation of the general principles of mastering.

G

Another amazing post G!
 
I can say with great confidence that everything mentioned by Gregorio is absolutely true. The best you can do is to build a transparent/neutral system and even then, what you get in the end is the mastering engineer's idea of what the recording should sound like and more often than not, even that is compromised by brickwalled hyper-compression or bad EQ choices.
 
Most mastering rooms are indeed very accurate and extremely revealing to the point that most people would not like to listen to most retail masters on such systems. However, as a mastering engineer, it is of the greatest importance that we get the most accurate and detailed view of the final mix so that we can adjust accordingly. The vast majority of mastering engineers will usually compromise the final mix in order to make it more consumer friendly. A few of us, never compromise and seek to produce the most dynamic and natural sounding recording possible which in turn, leads us to have very few jobs within a niche market.
 
Production and mastering will always have the greatest impact on your system. It is because of this that I have always advocated taking your time and researching before buying a particular album. Always seek out the better mastered pressings done by top notch mastering engineers and production teams. It's the best upgrade you can give your system...excellent masters.
 

 

[Chris J]

Hello G,
I wasn't trying to get too detailed or specific in my previous e-mail.
I understand that the mastering engineering is usually creating a master for the common man to listen to anywhere, not create a master for the audiophile sound system.
Which explains why we are all "punished" by overcompression, etc when we try to enjoy pop recordings on our audiophile systems.
Question, since professional recording standards are usually 48 k or 96 k would it make more sense for us to prefer 48 k consumer formats?
C

 

[Chris J]

Another amazing post G!
 
I can say with great confidence that everything mentioned by Gregorio is absolutely true. The best you can do is to build a transparent/neutral system and even then, what you get in the end is the mastering engineer's idea of what the recording should sound like and more often than not, even that is compromised by brickwalled hyper-compression or bad EQ choices.
 
Most mastering rooms are indeed very accurate and extremely revealing to the point that most people would not like to listen to most retail masters on such systems. However, as a mastering engineer, it is of the greatest importance that we get the most accurate and detailed view of the final mix so that we can adjust accordingly. The vast majority of mastering engineers will usually compromise the final mix in order to make it more consumer friendly. A few of us, never compromise and seek to produce the most dynamic and natural sounding recording possible which in turn, leads us to have very few jobs within a niche market.
 
Production and mastering will always have the greatest impact on your system. It is because of this that I have always advocated taking your time and researching before buying a particular album. Always seek out the better mastered pressings done by top notch mastering engineers and production teams. It's the best upgrade you can give your system...excellent masters.
 

My favourite tweaks and acessories are great sounding albums!

 

[khaos974]

Another amazing post G!
 
I can say with great confidence that everything mentioned by Gregorio is absolutely true. The best you can do is to build a transparent/neutral system and even then, what you get in the end is the mastering engineer's idea of what the recording should sound like and more often than not, even that is compromised by brickwalled hyper-compression or bad EQ choices.
 
Most mastering rooms are indeed very accurate and extremely revealing to the point that most people would not like to listen to most retail masters on such systems. However, as a mastering engineer, it is of the greatest importance that we get the most accurate and detailed view of the final mix so that we can adjust accordingly. The vast majority of mastering engineers will usually compromise the final mix in order to make it more consumer friendly. A few of us, never compromise and seek to produce the most dynamic and natural sounding recording possible which in turn, leads us to have very few jobs within a niche market.
 
Production and mastering will always have the greatest impact on your system. It is because of this that I have always advocated taking your time and researching before buying a particular album. Always seek out the better mastered pressings done by top notch mastering engineers and production teams. It's the best upgrade you can give your system...excellent masters.
 

Would it be possible to see a picture of your room? And the treatments for example?

 

[LFF]

Quote:

Would it be possible to see a picture of your room? And the treatments for example?

I can PM you some pics but you can always google "mastering room" and see some great examples.