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definitive definition of high definition

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#1
A good find, tried search didnt find the topic on this subject. Share your thoughts and experiences.

 

tomelex

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#2
I remember watching this long ago, and what an eye opener, for all kinds of things about audio recording, watch it all the way through to learn about the real world of audio. Excellent learning tool. Good Job for bringing this back up. He really casts a light on the world of recording.
 

Fitzcaraldo215

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#3
I think Waldrep makes many excellent points, some confirmed by scientific perceptual studies. I am not a huge fan of his releases, mainly on musical grounds, but they are often very good technically. I am also not crazy about his approach to mic placement for Mch, as revealed in some of his videos.

But, first, is it hidef or hirez? I prefer calling it hirez for audio, since hidef has already been heavily used, more or less appropriated, to describe video at higher than old "standard" pixel resolution - 2k, UHD, 4K, etc. He dwells on the definition of hirez, but I am satisfied with the definition that it is anything above RBCD's 44.1k PCM sampling rate and/or its 16 bit depth. Usually, today, that means 48k/24 on BD videos or 88k, 96k, 176k, 192k/24, etc. on downloads and some BD-As or DSD64 on SACDs or occasionally DSD128, 256, etc. on downloads.

I agree that hirez audio offers a mainly subtle difference over standard RBCD rez. I find the difference small but noticeable with consistency, and it may take some experience and learning to be able to identify it. Casual, untrained listeners might not hear much difference at first. I find the difference worthwhile, though. But, that perceptual difference may be lessened in playback by the increased modern practice of recording, mixing and mastering in hirez for release on downsampled stereo RBCD. (My experience here is mainly with classical music, not any dynamically compressed popular music.)

Probably his most significant point is that hirez must be maintained throughout the recording/playback chain. I agree completely. Many audiophiles are dismissive of any difference or advantage to it, but they were listening to remastered analog or just upsampled RBCD thinking it is hirez. So, their opinions are not surprising, but they are misleading and misinformed if that is their only basis.

For over 10 years, I have collected thousands of audio recordings and hundreds of video BDs in hirez. Most are in Mch. Most were recorded natively in hirez over the last 15 years. It is easily the best sound of my life time, and beyond my wildest fantasies of even a decade ago. I have bought no CDs in over a decade.

Some are analog stereo remasters, and many of those are excellent, but probably due much more to the remastering than the hirez format. For example, frequently cited as Greatest Recording of All Time, the '58-'65 Wagner Ring cycle with Georg Solti, the Vienna Philharmonic and a dream cast, never sounded nearly as good as Decca's 48k/24 remastering on BD-A. Music critics and I find it is sonically superior to the LPs, and much superior to the two earlier remasterings for CD, from which the BD-A was made, since the analog tape masters were unusable due to their age.
 

svart-hvitt

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#4
I think Waldrep makes many excellent points, some confirmed by scientific perceptual studies. I am not a huge fan of his releases, mainly on musical grounds, but they are often very good technically. I am also not crazy about his approach to mic placement for Mch, as revealed in some of his videos.

But, first, is it hidef or hirez? I prefer calling it hirez for audio, since hidef has already been heavily used, more or less appropriated, to describe video at higher than old "standard" pixel resolution - 2k, UHD, 4K, etc. He dwells on the definition of hirez, but I am satisfied with the definition that it is anything above RBCD's 44.1k PCM sampling rate and/or its 16 bit depth. Usually, today, that means 48k/24 on BD videos or 88k, 96k, 176k, 192k/24, etc. on downloads and some BD-As or DSD64 on SACDs or occasionally DSD128, 256, etc. on downloads.

I agree that hirez audio offers a mainly subtle difference over standard RBCD rez. I find the difference small but noticeable with consistency, and it may take some experience and learning to be able to identify it. Casual, untrained listeners might not hear much difference at first. I find the difference worthwhile, though. But, that perceptual difference may be lessened in playback by the increased modern practice of recording, mixing and mastering in hirez for release on downsampled stereo RBCD. (My experience here is mainly with classical music, not any dynamically compressed popular music.)

Probably his most significant point is that hirez must be maintained throughout the recording/playback chain. I agree completely. Many audiophiles are dismissive of any difference or advantage to it, but they were listening to remastered analog or just upsampled RBCD thinking it is hirez. So, their opinions are not surprising, but they are misleading and misinformed if that is their only basis.

For over 10 years, I have collected thousands of audio recordings and hundreds of video BDs in hirez. Most are in Mch. Most were recorded natively in hirez over the last 15 years. It is easily the best sound of my life time, and beyond my wildest fantasies of even a decade ago. I have bought no CDs in over a decade.

Some are analog stereo remasters, and many of those are excellent, but probably due much more to the remastering than the hirez format. For example, frequently cited as Greatest Recording of All Time, the '58-'65 Wagner Ring cycle with Georg Solti, the Vienna Philharmonic and a dream cast, never sounded nearly as good as Decca's 48k/24 remastering on BD-A. Music critics and I find it is sonically superior to the LPs, and much superior to the two earlier remasterings for CD, from which the BD-A was made, since the analog tape masters were unusable due to their age.
Just curious: What’s your take on 2L? They have all the hires and mch formats. Marketed as digital through and through.
 

RayDunzl

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#5
Just curious: What’s your take on 2L? They have all the hires and mch formats. Marketed as digital through and through.
I'm familiar with their freebie Sampler page...

Looking at a random (scrolled through the offerings) and first try pick (near the bottom), here are the format choices:

1528833749645.png
 

svart-hvitt

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#6
I'm familiar with their freebie Sampler page...

Looking at a random (scrolled through the offerings) and first try pick (near the bottom), here are the format choices:

View attachment 13146
Thanks Ray. I was more thinking about their technical-«artistical» quality, as evaluated by an experienced hires and mch user.

I can only listen to their stereo recordings, which are great to my ears.
 

RayDunzl

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#7
I have to wonder, with no specific "higher" resolution formats listed for that selection, what the MQA version does...
 

svart-hvitt

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#8
I have to wonder, with no specific "higher" resolution formats listed for that selection, what the MQA version does...
In fact, Morten Lindberg thinks MQA sounds better than DXD:

http://www.2l.no/hires/documentation/2L-MQA_Comparisons.pdf

After 2L presented that "note", I lost a bit of trust in the company (I can't understand why a simple algorithm beats man in a game like mastering).

But I still wonder how experience hires and much listeners find the sound and technical abilities of 2L.
 

Fitzcaraldo215

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#9
Just curious: What’s your take on 2L? They have all the hires and mch formats. Marketed as digital through and through.
Yes, hirez digital captured at PCM 352k= DXD in Mch sound. Often sold as 2 disc packages, a BD-A with a choice among different sampling rates or codecs, and a transfer to SACD. Some are BD-A only. Downloads in most all formats and sampling rates, including (gulp) MQA. Often very well engineered, although Amir found some very narrow band, ultrasonic spuriae in a few hirez files he tested, a hygiene issue perhaps stemming from a live monitor in the vicinity of the recording.

I do not think any other label offers more different sampling rate versions of their releases or is as venturesome about the latest recording technologies, such as (gulp) MQA.

No offense, but I am not captivated by all the obscure Scandinavian music. And, they avoid large scale orchestral. Other releases - Haydn Quartets, Brirtten, Bartok, Mozart, Grieg, etc. are enjoyable. However, they tend to emphasize on larger chamber ensembles a center of the ensemble, "surround sound" Mch perspective, which I do not particularly like. I am a die hard audience perspective guy.

Bottom line, a very interesting and credible label, but not one of my very favorites. Still, I like some of their recordings a lot.
 
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svart-hvitt

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#10
Yes, hirez digital captured at PCM 352k= DXD in Mch sound. Often sold as 2 disc packages, a BD-A with a choice among different sampling rates or codecs, and a transfer to SACD. Some are BD-A only. Downloads in most all formats and sampling rates, including (gulp) MQA. Often very well engineered, although Amir found some very narrow band, ultrasonic spuriae in a few hirez files he tested, a hygiene issue perhaps stemming from a live monitor in the vicinity of the recording.

I do not think any other label offers more different sampling rate versions of their releases or is as venturesome about the latest recording technologies, such as (gulp) MQA.

No offense, but I am not captivated by all the obscure Scandinavian music. And, they avoid large scale orchestral. Other releases - Haydn Quartets, Brirtten, Bartok, Mozart, Grieg, etc. are enjoyable. However, they tend to emphasize on larger chamber ensembles a center of the ensemble, "surround sound" Mch perspective, which I do not particularly like. I am a die hard audience perspective guy.

Bottom line, a very interesting and credible label, but not one of my very favorites. Still, I like some of their recordings a lot.
Thanks!

FWIW, 2L has some interesting bass on one of their recordings, a favorite of mine, which indicates that acoustic bass of high quality is intriguing (Quiet Winternight, an acoustic jazz project, J G Hoff et al.).
 

TBone

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#11
The term hi-rez has become meaningless, especially in terms of formats.

If it suppose to mean anything above 16/44; then it's totally dismissive of the vast amount of dynamically compressed examples which are defined as being "hi-rez" in content.
 

Jorj

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#12
Just curious: What’s your take on 2L? They have all the hires and mch formats. Marketed as digital through and through.
My opinion after listening carefully to the various formats is that the tracks on the 2L site benefit from a subjectively better master, not from the format. I test my hearing regularly, and it's a bit less sensitive in the 8kHZ range these days, but overall very good, and I can't hear any difference betwixt the various bit rates. Basically, 16/44 is more than adequate for me, and after that, I'm looking for non-botched engineering and production. HiRes is of no interest, and I await data to indicate that ABX testing shows a benefit.
 

Fitzcaraldo215

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#13
My opinion after listening carefully to the various formats is that the tracks on the 2L site benefit from a subjectively better master, not from the format. I test my hearing regularly, and it's a bit less sensitive in the 8kHZ range these days, but overall very good, and I can't hear any difference betwixt the various bit rates. Basically, 16/44 is more than adequate for me, and after that, I'm looking for non-botched engineering and production. HiRes is of no interest, and I await data to indicate that ABX testing shows a benefit.
I seriously doubt that a small, low sales volume label like 2L invests the time and money in preparing different masters from a recording session. I believe they use a one master stereo mix and one, sometimes two, master Mch mixes, all done at DXD sampling rate. They then downsample or convert from those masters to the various, multiple distribution formats on disc or for download. So, you should have from them a good apples to apples comparison of just different playback sampling rates.

As I said earlier, any advantage of hirez is usually subtle, though perhaps less subtle with experience and training. This echoes the main findings of the Joshua Reiss meta analysis paper on hirez a few years ago. And, in the experiments he summarized, even those with high average discrimination of hirez over RBCD, many test subjects, at least 25% or more as I recall, still heard no difference.

I am not a believer in ever escalating, higher and higher sampling rates myself. But, I also said that recordings produced in hirez, then downsampled to CD seem even harder to distinguish from playback in hirez. In other words, I think much of the advantage, if any, of hirez may be in recording production.

So, I am not totally surprised by your reaction. But, being a Mch devotee, I do not have much choice. Mch is almost always hirez. But, my anecdotal experience with that is downsampling hirez playback myself to RBCD or 48k/24 resolution on playback is subjectively less preferable to keeping playback in hirez. But, possibly the downsampling process I did in JRiver was the cause of that.

I also believe I have heard differences in the same recording at different hirez sampling rates, the higher 192k native one of the original recording being slightly but noticeably better subjectively than the 96k version. But, that was some time ago from the Linn site, not 2L.

I have not done any comparisons to 2L stereo CD versions, so I cannot confirm or deny your findings.
 

Jorj

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#14
I seriously doubt that a small, low sales volume label like 2L invests the time and money in preparing different masters from a recording session. I believe they use a one master stereo mix and one, sometimes two, master Mch mixes, all done at DXD sampling rate. They then downsample or convert from those masters to the various, multiple distribution formats on disc or for download. So, you should have from them a good apples to apples comparison of just different playback sampling rates.
You might be right, I'm not privy to their process. Due to the fact that they are promoting their content as HiRes and pushing MQA, they may have resorted to some chicanery (either with intent or accidentally) in the creation of their RBCD tracks in order to make them sound less-good, I'm not sure, but they do sound different, and if the spectrograms are to be believed, they ARE different. Their content is the first that I've been able to detect, after many attempts, an audible difference between HiRes and RBCD. Either my ears just got better, or they did something tricksy.
 

Fitzcaraldo215

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#15
You might be right, I'm not privy to their process. Due to the fact that they are promoting their content as HiRes and pushing MQA, they may have resorted to some chicanery (either with intent or accidentally) in the creation of their RBCD tracks in order to make them sound less-good, I'm not sure, but they do sound different, and if the spectrograms are to be believed, they ARE different. Their content is the first that I've been able to detect, after many attempts, an audible difference between HiRes and RBCD. Either my ears just got better, or they did something tricksy.
I honestly do not believe that 2L resorts to anything underhanded. There never was any evidence of that. You may wish to tar Morten Lindberg for supporting MQA, but that makes him guilty of exactly nothing. Many others have, many quite respectable, as well. He is just a venturesome pioneer. For example, he was one of the first to embrace BD-A and 352k PCM recording.

There is no such thing as guilt by association in my book. Proof is necessary. His recordings and reputation speak for themselves. And, I personally care little about MQA, and I do not see it as becoming much of a factor, except possibly in streaming, if it survives, that is. But, I do not irrationally fear and loathe it or those associated with it, either.
 

Theo

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#16
I am personally ok with the CD format, which is high high resolution for me (and I would assume to most if not all ears... human and above 18 years old?).
So, hi-res to me is a recording which has been made with an equipment which is 16bits/44.1kHz capable and with no or little compression. So, as suggested in the video, I would like to have this documented somewhere when I buy an album. At the beginning of the CD area, you would know if the original recording was coming from analog tapes or not... It was printed on the cover with the AAD - ADD or DDD code. What happened to these? You can't find it anymore, even on remastered songs from the 70's and certainly not on the main streaming/download sites.
Wouldn't it be great if we could have a code indicating how conformable to CD specs a file or disc is? Like Dynamic range and frequency range? I don't care about the number of bits or container (format like AAC, MQA, DSD...) as long I know the sound specs I can get from the recording I buy.
 
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#17
This is a good read. Long but worthwhile

From "Digital Audio Explained, for the Audio Engineer," by Nika Aldrich....
It seems to me that there is a lot of misunderstanding regarding what bit depth is and how it works in digital audio. This misunderstanding exists not only in the consumer and audiophile worlds but also in some education establishments and even some professionals. This misunderstanding comes from supposition of how digital audio works rather than how it actually works. It's easy to see in a photograph the difference between a low bit depth image and one with a higher bit depth, so it's logical to suppose that higher bit depths in audio also means better quality. This supposition is further enforced by the fact that the term 'resolution' is often applied to bit depth and obviously more resolution means higher quality. So 24bit is Hi-Rez audio and 24bit contains more data, therefore higher resolution and better quality. All completely logical supposition but I'm afraid this supposition is not entirely in line with the actual facts of how digital audio works. I'll try to explain:
When recording, an Analogue to Digital Converter (ADC) reads the incoming analogue waveform and measures it so many times a second (1*). In the case of CD there are 44,100 measurements made per second (the sampling frequency). These measurements are stored in the digital domain in the form of computer bits. The more bits we use, the more accurately we can measure the analogue waveform. This is because each bit can only store two values (0 or 1), to get more values we do the same with bits as we do in normal counting. IE. Once we get to 9, we have to add another column (the tens column) and we can keep adding columns add infinitum for 100s, 1000s, 10000s, etc. The exact same is true for bits but because we only have two values per bit (rather than 10) we need more columns, each column (or additional bit) doubles the number of vaules we have available. IE. 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024 .... If these numbers appear a little familiar it is because all computer technology is based on bits so these numbers crop up all over the place. In the case of 16bit we have roughly 65,000 different values available. The problem is that an analogue waveform is constantly varying. No matter how many times a second we measure the waveform or how many bits we use to store the measurement, there are always going to be errors. These errors in quantifying the value of a constantly changing waveform are called quantisation errors. Quantisation errors are bad, they cause distortion in the waveform when we convert back to analogue and listen to it.
So far so good, what I've said until now would agree with the supposition of how digital audio works. I seem to have agreed that more bits = higher resolution. True, however, where the facts start to diverge from the supposition is in understanding the result of this higher resolution. Going back to what I said above, each time we increase the bit depth by one bit, we double the number of values we have available (EG. 4bit = 16 values, 5bit = 32 values). If we double the number of values, we halve the amount of quantisation errors. Still with me? Because now we come to the whole nub of the matter. There is in fact a perfect solution to quantisation errors which completely (100%) eliminates quantisation distortion, the process is called 'Dither' and is built into every ADC on the market.
Dither: Essentially during the conversion process a very small amount of white noise is added to the signal, this has the effect of completely randomising the quantisation errors. Randomisation in digital audio, once converted back to analogue is heard as pure white (un-correlated) noise. The result is that we have an absolutely perfect measurement of the waveform (2*) plus some noise. In other words, by dithering, all the measurement errors have been converted to noise. (3*).
Hopefully you're still with me, because we can now go on to precisely what happens with bit depth. Going back to the above, when we add a 'bit' of data we double the number of values available and therefore halve the number of quantisation errors. If we halve the number of quantisation errors, the result (after dithering) is a perfect waveform with halve the amount of noise. To phrase this using audio terminology, each extra bit of data moves the noise floor down by 6dB (half). We can turn this around and say that each bit of data provides 6dB of dynamic range (*4). Therefore 16bit x 6db = 96dB. This 96dB figure defines the dynamic range of CD. (24bit x 6dB = 144dB).
So, 24bit does add more 'resolution' compared to 16bit but this added resolution doesn't mean higher quality, it just means we can encode a larger dynamic range. This is the misunderstanding made by many. There are no extra magical properties, nothing which the science does not understand or cannot measure. The only difference between 16bit and 24bit is 48dB of dynamic range (8bits x 6dB = 48dB) and nothing else. This is not a question for interpretation or opinion, it is the provable, undisputed logical mathematics which underpins the very existence of digital audio.
So, can you actually hear any benefits of the larger (48dB) dynamic range offered by 24bit? Unfortunately, no you can't. The entire dynamic range of some types of music is sometimes less than 12dB. The recordings with the largest dynamic range tend to be symphony orchestra recordings but even these virtually never have a dynamic range greater than about 60dB. All of these are well inside the 96dB range of the humble CD. What is more, modern dithering techniques (see 3 below), perceptually enhance the dynamic range of CD by moving the quantisation noise out of the frequency band where our hearing is most sensitive. This gives a percievable dynamic range for CD up to 120dB (150dB in certain frequency bands).
You have to realise that when playing back a CD, the amplifier is usually set so that the quietest sounds on the CD can just be heard above the noise floor of the listening environment (sitting room or cans). So if the average noise floor for a sitting room is say 50dB (or 30dB for cans) then the dynamic range of the CD starts at this point and is capable of 96dB (at least) above the room noise floor. If the full dynamic range of a CD was actually used (on top of the noise floor), the home listener (if they had the equipment) would almost certainly cause themselves severe pain and permanent hearing damage. If this is the case with CD, what about 24bit Hi-Rez. If we were to use the full dynamic range of 24bit and a listener had the equipment to reproduce it all, there is a fair chance, depending on age and general health, that the listener would die instantly. The most fit would probably just go into coma for a few weeks and wake up totally deaf. I'm not joking or exaggerating here, think about it, 144dB + say 50dB for the room's noise floor. But 180dB is the figure often quoted for sound pressure levels powerful enough to kill and some people have been killed by 160dB. However, this is unlikely to happen in the real world as no DACs on the market can output the 144dB dynamic range of 24bit (so they are not true 24bit converters), almost no one has a speaker system capable of 144dB dynamic range and as said before, around 60dB is the most dynamic range you will find on a commercial recording.
So, if you accept the facts, why does 24bit audio even exist, what's the point of it? There are some useful application for 24bit when recording and mixing music. In fact, when mixing it's pretty much the norm now to use 48bit resolution. The reason it's useful is due to summing artefacts, multiple processing in series and mainly headroom. In other words, 24bit is very useful when recording and mixing but pointless for playback. Remember, even a recording with 60dB dynamic range is only using 10bits of data, the other 6bits on a CD are just noise. So, the difference in the real world between 16bit and 24bit is an extra 8bits of noise.
I know that some people are going to say this is all rubbish, and that “I can easily hear the difference between a 16bit commercial recording and a 24bit Hi-Rez versionâ€. Unfortunately, you can't, it's not that you don't have the equipment or the ears, it is not humanly possible in theory or in practice under any conditions!! Not unless you can tell the difference between white noise and white noise that is well below the noise floor of your listening environment!! If you play a 24bit recording and then the same recording in 16bit and notice a difference, it is either because something has been 'done' to the 16bit recording, some inappropriate processing used or you are hearing a difference because you expect a difference.
G
1 = Actually these days the process of AD conversion is a little more complex, using oversampling (very high sampling frequencies) and only a handful of bits. Later in the conversion process this initial sampling is 'decimated' back to the required bit depth and sample rate.
2 = The concept of the perfect measurement or of recreating a waveform perfectly may seem like marketing hype. However, in this case it is not. It is in fact the fundamental tenet of the Nyquist-Shannon Sampling Theorem on which the very existence and invention of digital audio is based. From WIKI: “In essence the theorem shows that an analog signal that has been sampled can be perfectly reconstructed from the samplesâ€. I know there will be some who will disagree with this idea, unfortunately, disagreement is NOT an option. This theorem hasn't been invented to explain how digital audio works, it's the other way around. Digital Audio was invented from the theorem, if you don't believe the theorem then you can't believe in digital audio either!!
3 = In actual fact these days there are a number of different types of dither used during the creation of a music product. Most are still based on the original TPDFs (triangular probability density function) but some are a little more 'intelligent' and re-distribute the resulting noise to less noticeable areas of the hearing spectrum. This is called noise-shaped dither.
4 = Dynamic range, is the range of volume between the noise floor and the maximum volume.
 

DonH56

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#20
Name from the past: Nika was my first sales engineer at Sweetwater Sound 20+ years ago before he changed careers.
 
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