"The Beginner’s Guide to Hi-Res Audio"

  • 7 December 2021
  • 92 replies
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Userlevel 7

The 13.4.1 S2 update added hi-res (Ultra HD) and Dolby Atmos audio support from Amazon Music Unlimited. With this update, Sonos released this great article about hi-res audio and how you can listen to it on Sonos. It’s a very detailed and well-written article:

https://blog.sonos.com/en-us/hi-res-audio-guide


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92 replies

I am not saying that current hi-res recodings are better sounding than CD-quality!

I am just saying that current 2D recordings in CD-quality are not adequately capturing/reproducing the binaural experience in a conert hall. You may come to the conclusion that for 2D audio formats, CD quality is as good as it gets and no further improvements are possible from there, fine. But this is also just an opinion based on the negative results of studies perfroming fromal listening tests. As stated above, negative results deliver no proof for the non-existence of some phenomenon. They just prove that in this case CD-quality could adequately capture what’s in the corresonding hi-res recording under test. 

I for one belive that even for 2D audio there are advances to be made which are related to the reproduction of the phase spectrum as “the human hearing system will resolve small time differences which might imply a wider bandwidth in a linear system”.

It’s prefectly fine if you have a different opinion

 

It sounds more like you’re saying that listening to a live acoustic performance is not accurately reproduced by a 2 channel recording at CD quality.  I would agree with that.  However, that does not mean that hi res  audio is the solution, particularly when  it’s tested and failed.  The factor that seems to be forgotten is that room acoustics, reflections, absorptions, direction of audio, and likely visual ques, come in to play to effect what we hear.  While you could reproduce some of that with pyscho accoustic effects, timing modifications, etc, you still can’t quite reproduce it with 2 channels.   Even then you brain is still aware that what it’s hearing is a recording rather than a live performance, and that surely factors in to some extent.

So it seems logical to me that instead of pushing higher resolution, it would make more sense, to me anyway,  to work on improving room acoustics, additional audio channels, speakers that operate closer to how instruments actually produce,  sound, etc.  That’s not even realistic though, since environments are created for purpose beyond mimicking the acoustics of a concert hall.   But sure, there is room for growth in audio reproduction, but saying that it needs to occur with higher resolution rather than other issues, doesn’t make a ton of sense.

And your statement “Yeah, internet formus seem to attract those flat-earthers who use negative results to prove the non-existence of any given phenomenon.” is just silly in this context.   You can absolutely prove that A doesn’t cause B when you repeatedly demonstrate that A doesn’t cause B.   Negative results don’t prove anything when we do not have the testing capability to examine an entire sample.  For example, just because we have not seen life on other planets does not prove that there is no life on other planets because we can not test the entire population of planets.  Flat earth is very different as we have proven that the earth is round, and flat earth believe that those that did the test are lying about their results.

Userlevel 7
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Software Engineers think of this kind of stuff all the time.  It’s what they do.

 

Indeed. On the other hand sales folks concentrate on not leaving any money on the table. They are good and have no shame… 

So you get: 1.5-meter Ethernet cable for $499.

https://www.networkworld.com/article/2281260/denon-s-outrageous-price-for-ethernet-cable.html

“The manufacturer is Denon, and the target customer is the "audio enthusiast." Apparently "audio enthusiast" is Denonese for "sucker."”

The bigger net thing is the biggest crock I've ever seen in print.  The 16 bit "net" is already big enough to record a mosquito in the room followed by a jack hammer.  How big a net do you need? 

Userlevel 5
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Also I am curious what the difference is with Amazon’s HD vs Sonos Radio HD or are they the same?

Sonos Radio HD streams in 16-bit/44.1 kHz 

IIRC Amazon HD streams in up to 24-bit/192 kHz, but on Sonos it is 24/48. 
 

Whenever I watch HD quality video streams, I don’t need any badges on the screen to let me know what quality I am seeing - and when the stream quality drops occassionally because of broadband issues, this too is immediately obvious. 

Clearly this analogy does not apply for Hi Res Audio, seeing how people are looking for badges to get a confirmation of what is streaming, because, I suppose, their ears are not telling them this. If so, why bother?

And, as of today, you can now listen to hi-res (24-bit, 48 kHz) audio on most Sonos products by streaming from Amazon Music Unlimited. Why would you want to listen to music in hi-res? Again, McAllister explains. “The benefit of listening to hi-res music is that you’re listening to the actual file from the studio,” he said. “No conversion had to take place to change the 24-bit track into a 16-bit track. Listening to a track at 24-bit is a guarantee that you’re hearing the audio exactly as it sounded in the studio. To get a bit technical for a moment, if all digital files are made up of just ones and zeros, the file you’re listening to in 24-bit is made up of the exact same ones and zeroes that came out of the studio.”

 

I don’t think I accept this reasoning.  It basically implies that the process of going from 24 bit to 16 bit can corrupt the audio somehow.  I don’t think that’s the case.  If I read the article correctly, seems like there should be more concern with the audio file is lossy or lossless as that’s where audio could be removed. It sort of feels like asking a waiter  to bring out an entire cake, even though you can only consume a slice of it.

Also thought the list of supported devices was interesting, since the new SYMFONISK picture frame was not compatible with hires, even though it’s one of the newer models. 

So what audio quality do you get with a home theatre room setup where the rear speakers are not hi res compatible? For example, a Beam with Play:1s for surround.  Does it matter if you are in full mode or not?

 

It seems we’re now in the realm of Dirac impulses which, to my mind, don’t have much to do with music. :rolling_eyes:

Indeed the first reference says “Localisation performance is better for non-musical sounds (e.g., clicks, percussive noises, etc.) than for musical tones”. Presumably this accounts for the 1 degree figure.

It depresses me Sonos bought into the hogwash.  Marketing got the better of them. 

It is ok to do it because everyone else is. What is not ok is using science in a misleading way to proclaim the benefit. Especially having used science in the past to justify not offering hi res.

No claims about quality anywhere.

What about:

 Why would you want to listen to music in hi-res? Again, McAllister explains. “The benefit of listening to hi-res music is that you’re listening to the actual file from the studio,” he said. “No conversion had to take place to change the 24-bit track into a 16-bit track. Listening to a track at 24-bit is a guarantee that you’re hearing the audio exactly as it sounded in the studio. 

Implicit in the quote is that with 16 bit what you are hearing isn't exactly as it sounded in the studio...

Quite true, but nor can headphones create bass that one can feel as well as hear.

Good point; but I haven't used headphones enough to say more, In any case, this isn't applicable to the Hi Res subject that isn't about such macro - if I may use that word - effects.

This is why digital audio with increased sampling rates of 96kHz or even 192kHz would indeed provide a very noticeable benefit as it allows for more precise positioning and depth of the sound sources.

On that basis the difference between Red Book and Hi Res in any blind test should be like ‘night and day’, and yet: https://www.realhd-audio.com/?p=6993

Cite what??

 

Actual evidence for your claim.  

 

Userlevel 6

So what audio quality do you get with a home theatre room setup where the rear speakers are not hi res compatible? For example, a Beam with Play:1s for surround.  Does it matter if you are in full mode or not?

 

I am curious about this. 

 

I can get Dolby Digital/Ultra HD where Play:3s are used as surrounds with an Arc and gen 2 Sub. 

When Dolby Digital is playing, the full/ambient setting does not apply, but you can switch between them for Ultra HD songs and it plays under both settings without any issue.

Cite what??

 

Actual evidence for your claim.  

 

If you are refering to my last statement about the audible difference between currently available HD and UltraHD tracks, that is more a conclusion, based on those fundamentals of digital signal porcessing which I tried to briefly summarize before, rather than a claim.

 

How about the claim that “digital audio with increased sampling rates of 96kHz or even 192kHz would indeed provide a very noticeable benefit as it allows for more precise positioning and depth of the sound sources.”

Cite what??

 

Actual evidence for your claim.  

 

If you are refering to my last statement about the audible difference between currently available HD and UltraHD tracks, that is more a conclusion, based on those fundamentals of digital signal porcessing which I tried to briefly summarize before, rather than a claim.

 

You’ve clearly done enough research on the topic to know that what you’ve stated is far from accepted fact. You had to know that if you post a theory like this on a forum with others knowledgeable on the subject, it’s not going to be blindly accepted.

Userlevel 6

 

“HD” for Amazon sort of has two different meanings.  HD is the name of the service level you can get within Amazon music.  Within that service, you’ll have SD (Standard definition) tracks of the lower quality.  HD tracks are 16-bit/44.1 kHz (CD quality)  and then there are Ultra HD tracks at 24 bit.  There is also now the atmos music as part of this service.  When playing Amazon music on Sonos, Sonos will have no label for SD, HD for HD, Ultra HD label, and Atmos label.

 


In the UK at least, Amazon has recently updated so HD/Ultra HD/Dolby Atmos are now all under the service “Amazon Music Unlimited”, there is no separate “HD” service.

The respective audio resolution badge only appears when initiating playback from Amazon Music, within the Sonos app. No badge currently appears when casting to Sonos from the Amazon Music app by airplay etc.

Why can’t the music industry standardize these designations and require compliance. Not sure who or how it would be done, just want transparency and honesty not marketing speak. 

 

An industry, or more accurately just an industry related group, can create a standard, but they can never require compliance. All they can really do is market and educate the public on what the standard is, why it’s important, and make sure the standard is followed strictly by product that applies and claims to meet the standard.  if the public doesn’t know or care about the standard, and it’s loosely enforced, then it’s pointless.  All that takes a lot of money, and generally speaking, if it doesn’t help increase sales, why bother.   I think the different music services primary means of competing is on audio quality, so they don’t have a big interest in standards.

That said.  it seems standards pretty much existed and worked in the days of physical media.  Once everything  stated going digital and ‘customers’ pirated music in whatever format and quality they wanted, things got all shot to hell.  Even when you could start buying music digitally, the industry didn’t want you to know that the quality was worse than CD.

 

 

Userlevel 3
Badge +2

Ahh, I see, good catch!

 

This is the way it was always going to turn out.  The conversation continues until you get caught in a trap.  There was never going to be another outcome.

A small digression out of curiosity - why was an “odd” number- 44100 - selected in the first place? If 40000 needed a margin of safely, why not 48000? Or even 44000?

 

Several reasons.  It was the Sony standard for PCM, it's a product of prime numbers (2*2*3*3*5*5*7*7), which makes calculations easier,, and one of the things the CD consortium insisted on was Beethoven's 9th Symphony would fit on one disc (but this was more related to the debate on the size of the disk).

Userlevel 2
Badge +2

The Hi Res audio push seems inevitable regardless of whether it makes any real difference or not. It has become just another spec tick box you have to have if you want to sell audio products in 2022.  My guess is the increased cost of the bandwidth is so insignificant to streaming music services they are like “why not?”,  If it hooks a few more customers it will be worth it. 

Most listeners won’t know or care.  But there is a certain population out there who will be lured in by the promises. Just like there used to be a certain population people will argue bitterly about megapixels in cameras long after we passed the limits of what really mattered. Some people just love to bicker about numbers I guess.

It does make me chuckle when I see people fretting about whether they are hearing Hi Res audio on their Sonos Roam other tiny speakers.  Hell even on a Port connected to a really nice Denon/Aperion Audio setup I can’t hear a difference so what chance do they have on what’s essentially a 200 dollar bluetooth speaker?  

Userlevel 5
Badge +9

Also I am curious what the difference is with Amazon’s HD vs Sonos Radio HD or are they the same?

Sonos Radio HD streams in 16-bit/44.1 kHz 

IIRC Amazon HD streams in up to 24-bit/192 kHz, but on Sonos it is 24/48. 
 

 

“HD” for Amazon sort of has two different meanings.  HD is the name of the service level you can get within Amazon music.  Within that service, you’ll have SD (Standard definition) tracks of the lower quality.  HD tracks are 16-bit/44.1 kHz (CD quality)  and then there are Ultra HD tracks at 24 bit.  There is also now the atmos music as part of this service.  When playing Amazon music on Sonos, Sonos will have no label for SD, HD for HD, Ultra HD label, and Atmos label.

 

 

When comparing services, for me at least, it’s helpful to set aside the marketing speak, (SD, HD, Ultra HD) because the meaning varies on the context.

On Sonos if you don’t own an Atmos enabled product, Amazon Unlimited can stream in up to 24/48 (may vary depending on your location)

 

 

Userlevel 6

As far as the resolution badge, I think it’s in SD (no badge)  when initiating playback from the Amazon app or Alexa because Amazon doesn’t know what resolution the specific Sonos room can play.  That’s my theory anyway.

 

 

Yes, I also believe it is SD rather than the respective badge just not showing.

I’ve noticed whilst playing around with Ones, it takes a few seconds/attempts before Ultra HD appears. Sonos must do some monitoring of the network to establish what quality to play, although Dolby Atmos music plays straight away with the Arc. Hmmmm that’s maybe why I can’t get the paired Ones and Sub to play Ultra HD… Need to troubleshoot some more…

 

Who would have thought that?! Interesting.

 

Software Engineers think of this kind of stuff all the time.  It’s what they do.

Example:  The most efficient file sorting technique is to sort the files by dividing them up into separate files following the Fibonacci Sequence.  There’s also a search technique based on the Fib.  Both are proven to have a Log n algorithmic complexity, which is as good as you can get.

Ahh, I see, good catch!

 

This is the way it was always going to turn out.  The conversation continues until you get caught in a trap.  There was never going to be another outcome.

Yeah, internet formus seem to attract those flat-earthers who use negative results to prove the non-existence of any given phenomenon.  I don’t really bother especially if the most compelling counter argument they present is that they have never heard about it garnished with a hint on the many yeears of experience they have under their belt.

But for arguments sake, you may want to read J. Robert Stuarts’s paper on “Coding for High-Resolution Audio Systems”, published 2004 in the Journal of the Audio Engineering Society. Everything I have stated about sampling rate and high frequency content you can more or less find in Chapter 5 of this paper, and in particular section 5.1 Psychoacoustic Data to Support Higher Sampling Rates:”...It has been suggested that perhaps higher sampling rates are preferred because, somehow, the human hearing system will resolve small time differences which might imply a wider bandwidth in a linear system. In considering this it is important to distinguish between perceiving separate events which are very close together in time (implying wide bandwidth and fine monaural temporal resolution) and those events which help build the auditory scene, for which the relative arrival times are either binaural or well separated. In the first case, wider bandwidth is required to discriminate acoustic events that are closer together in time. This seems to be an alternative statement of the problem to determine the maximum bandwidth necessary for audible transparency...Events in time can be dis- criminated to within very fine limits, and with a resolution very substantially smaller than the sampling period. This point is crucial because provided we treat all channels identically to ensure no skew of directional information, there is no direct relationship between the attainable tem- poral resolution and the sampling interval.

So independet of whether you follow the author’s hyphotheses and findings or not, it is a well known paper from an AES Fellow, so you cannot really say that you never heard about this stuff.  

 

 

That AES Fellow has an direct financial relationship to the promotion of high resolution audio formats.  You might as well consult Dr. Daffy on whether his Magic Elixir cures all ails. 

 

Following this paper in 2007 there has been an article from Meyer and Moran, also published in the AES Journal, whith the objective to find out if there are any audible gains from high-res audio playback by doing some extensive, formalized testing. Their conclusion was that based on their test methodology they could not find any significant preference for hi-res audio over the CD standard, even when using high-end headphones or speaker systems. However, they very correctly noted that “it is very difficult to use negative results to prove the inaudibility of any given phenomenon or process”. The most intriguing part of this arcticle, however, was their final note on high-resolution recordings: “Though our tests failed to substantiate the calimed advantages of high-resolution encoding for two-channel audio, one trend became obvious...throughout our testing: virtually all of the SACD and DVD-A recdoings sounded better than most CD’s - sometimes much better...Partly because[...]engineers and producers are give the freedom to produce recodings that sound as good as they can make them, without having to compress or equalize the signal to suit lesser systems.

And here we go. I truly belive there are advances to be made in capturing and reproducing more accurately what our ears actually perceive in a concert hall. I am a big fan of innovation. And the proliferation of Hi-Res audio formats as we are witnessing right now is certainly one way to inspire more innovation to come forward in this field. Even if we are not (yet) experiencing it in the UltraHD tracks we get to listen to today.

 

 

Are you actually trying to use Meyer and Moran’s results to suggest SACD and DVD-A recordings are superior to CD, when their results showed all differences were due to mastering and not higher resolution formats?  Pretty freaking bold move!  But as before, your bluster doesn’t work here.