48kHz vs 96kHz: audible?


As a so-called audiophile, it is easy to lose one’s balance within many discussions and end up doubting, or at least questioning, whether that subtlety which one hears is real or imaginary.
 
Today, while engaged in a pastime, I was playing Holst’s "The Planets" in the background, but not at a low volume. I thought that it didn’t sound right. The strings in particular sounded a little abrasive. I noticed this on "Mars," the first composition, so it didn't take me long to perk up. On closer examination, I noticed that the DAC front panel was reporting 48kHz sample rate. I knew that this version of The Planets is 96kHz. Sure enough, JRiver Media Center (MC) was converting all PCM data (whether higher or lower) to 48kHz upon playback. I fixed the MC settings back so that all PCM rates play back at their native rates (up to the capability of my DAC), and all is well now.
 
Sometime in the recent past, whether due to an application or OS upgrade (of which there was one a few days ago), the MC sample rate conversion table got corrupted or reverted to a default configuration.
 
It would seem that I am able to hear the difference between 48kHz and 96kHz, at least under these circumstances. The difference was enough that I noticed it while passively listening (I was focused on drawing; the music was “background”) before I suspected a technical issue.

I wonder whether I could have heard this difference in a formal ABX test session? From my past experience with ABX testing, when the differences between the test objects are subtle, observations could easily have been obfuscated due to mental noise consisting of test anxiety, listening fatigue (to same passage over and over) and tedium. Whereas, in my case above, I noticed the difference when I was relaxed and focusing on something else entirely.

I am interested in thoughtful replies.

128x128mcdonalk
Post removed 

I'm not a big digital head, but on my Node 2i I can usually tell the difference between CD quality and Hi-res.  Though I must admit, I believe it's highly dependent on the mastering.  I've heard some excellent CD quality streams, and some pretty bad high res streams.

Hi there,

So here are my thoughts:

1 - New DAC’s do a lot better with Redbook data than dac’s more than 10 years old.

2- While they do perform much better, there is still a measurable difference in performance of the anti-aliasing filters in the top octave so I’m not surprised it’s audible, but what it’s not is significantly better any more.

In the past, 96/24 music had a significant delta to 44/16 data. That’s mostly vanished, and any changes I hear can be replicated by a decent upsampling algorithm. This tells me that the mathematicians were partly right, that 44.1 kHz was good enough to encode music, but they were partly wrong in that there was a bigger delta due to how DAC’s handled different data density.

It’s time to stop buying DACs because hi rez sounds so much better, it doesn’t. Your DAC just sounds bad with Redbook. 🤣

TBC: I upsample to 96/24 when necessary, and otherwise am happy to stream 96/24 from Quboz.  I still prefer the DAC performance at this sample rate, but I don't think it's the data so much as the filter performance.

Isn't it possible that you are simply hearing  the artifacts of JRiver's extra step to downsample the file due to your software setting?  Maybe you're just comparing the effects of "native" to improperly refiltered/resampled streams.

Hard to actually draw any actual conclusions from this.

I haven't gone that far with your supposition (48 vs 96), but I did blind A/B listening with a friend testing my CD 16/44.1 files vs 24/48 and 24/96 HD files and was able to discern between the two 90% of the time.

So is it possible, absolutely. Could there be another explanation, absolutely also.

But your experience is interesting.

Last time I used JRiver, Hi-Res didn’t exist. 😀

I guess I’ll have to see what all it does these days. Oh drat, there isn’t an iOS app for it yet. Guess I’ll have to fire up the laptop.

 

sandstone best me to the real point.

You cannot be sure of hearing things that do not exist. We know that the downsampling DOES exist by your description.

it should be no problem hearing a difference 96 Khz is much better than 48 kilohertz.

I have found similar situations but with streaming from Qobuz. I regularly go in search of new music and pay no attention to the sample rate when selecting songs. Many times I’ll be listening and the difference in how smooth the tones are makes me check the sample rate and it’s almost always 96 or above. However, if I then start to try and replicate this actively I find sometimes I’m assuming a CD quality file might be high res. There is a definite difference for me when I’m just normally listening, but it clearly depends how good the mastering is of a CD quality file as some of them can sound superb. Whenever my ears perk up to check a sample rate it’s always because of how much smoother it is, I’ve always just assumed more data means a smoother crescendo of sound, if that makes sense.

It is possible that JRiver Media Center's downsampling was done poorly and became more noticeable than if it had been done correctly. A lot of what we "hear" comparing different resolutions is dependent on how familiar we are with the music being played. Obviously you know the Holst very well, but would you have noticed the difference (or any difference) on a less familiar one?

This whole area is a bit of a minefield. The ideal way to test this hypothesis would be to take a piece of music that can be mechanically performed -using something like the technology that was used for the Zenph reperformance of the Goldberg Variations. One would then have the computerised piano play the piece of music twice and record it at the two sampling rates/word lengths, and then double blind test it across a stratified sample of listeners using a high resolution playback system.

In other situations where upsampling and downsampling is involved, it's hard to discern cause and effect.

Qobuz is my sole front end, and I hear a slightly more refined attack on each note on most hi-res selections. However I find hi-res content overall of inconsistent quality and less the driver of SQ (compared to Redbook) than the recording/mastering put into it, so much so that I no longer even care what its published resolution is, FWIW.

Hmm. I suspect that what you were hearing may not be SQ difference between sample size, but problems in how your box downsamples digital signals. 
 

Downsampling problems show up in edge cases, like high violins, reverb tails, etc. For downsampling to sound good, dither (digital noise) needs to be used to minimize aliasing/rounding errors during the conversion. There are several ways to do this, which is best done when mastering the recording. Sounds like your streamer might just be lopping off bits on the fly?  And you heard it.  Might be interesting to find out how your box downsamples and what kind of dither is used, if any. 

A lot of problems can be introduced when sample sizes get changed without close attention. 

@mcdonalk , just a quick question for you: You say you were listening "in the background" while engaged in some other pastime. Once you noticed or sensed the sonic anomaly, did you, then, complete your final evaluation by doing some bona fide critical listening from the sweet spot? I can only assume that you did so in your final analysis because no matter how great your speakers' off-axis response might be, the best position for critical listening is the sweet spot.

yes, significant difference between 48k and 96k, has already been done in studios quite a few times. 

next level up is 192k, which is slightly better than 96k, but at these 192k sampling rates and higher, you need a master clock to sync the data. 

The only way you can be sure is to compare apples to apples:

Dr. Aix

  Then post your results. Lotso luck.

 

 

 

To help sort this out you might try visiting the download bench at 2L recordings for great music in a variety of formats and resolution levels w same master… quite helpful… mostly free :-) 2L the Nordic sound :-)

jim

Qobuz has both high rez. and CD rez. files and I can distinguish the higher resolution ones as richer and more 3D sounding, smoother and more colorful. I find the difference significant, by far less important as the actual mastering.

On the other hand, I have recorded myself playing the digital piano. The midi file can then be made by the Pianoteq software into a wav and I can choose the resolution. The 24/192 file sounds marginally, and I emphasize marginally, better than the 22/48 file, the sustain or decay, whatever you would call it, is a bit longer and richer in detail.

All of the above on a quite resolving system (Marin Logan hybrids and Accuphase electronics).

There's no question that I can hear the difference between CD and high rez. As important, however, is the quality of the recording setup and the art of the sound engineer. I've heard some poorly recorded music that is high rez. It might as well have been played on my car radio.

Very interested in the topic having spoken to a recording engineer friend of mine and having read what I can comprehend. I sort of understand now why hi res matters in the studio and the mastering. But I'm having trouble understanding how, if it's done properly in the studio at hi res, that there could be any audible difference between a release at 16/44.1 and a release at say 24/96 or even higher, again assuming the same master was used. For bit depth, wouldn't it only matter if there was a dynamic range that doesn't practically exist and for sample rate, wouldn't it only affect ranges we can't hear? I have read that the difference we think we hear is either a) that a different master was used for the hi res release and we're not really listening to the same recording when we compare CD to HR or b) it's all in our heads. My "general observation" in my reading is that people on the recording/studio side of things think hi res in the playback environment is not really a thing and people in the playback business think it's massively important.  I don't know the answers but willing to learn especially about the science/math behind it (less interested in people's listening experiences as I know they cover the full spectrum of opinion and we're all subject to bias whether we like it or not).

I had some songs in both 16/44.1 and 24/96 and there was a definite difference.  The 24/96 versions sounded smoother and more full/rich.  Anyway, that was my experience

…like i said…. check out 2L….recording engineer of renown runs the place…

But I’m having trouble understanding how, if it’s done properly in the studio at hi res, that there could be any audible difference between a release at 16/44.1 and a release at say 24/96 or even higher, again assuming the same master was used.

My understanding is that filters are used to eliminate noise from digital processing above 1/2 the sampling rate. For a 44.1khz sampling rate this puts the filtering pretty close to the audible range and can cause distortion in that range. 96khz puts the filtering at 48khz well above the audible range. Of course digital filtering is improving so any harm it does is probably lessening as time goes on.

I’m not a technical person so maybe someone who is can give a more accurate explanation of what is going on between 44.1 and hi-res.

 

From my experience I'd suggest any differences being heard are coming from the conversion process of altering bit rates rather than the rates.

In other words do not convert bit rates.

Perhaps there is some equipment that can do it without downgrading the sound quality. 

@tomcy6  is correct. 
 

The reason oversampling gives the impression that it may sound better is not due to the oversampling process itself but due to the fact that at higher sample rates, filter artifacts are pushed to higher frequencies which you cannot hear. If a standard CD player employs very good filters (more expensive to build than oversampling), they would sound just as good.

There have been multiple suggestions here that Media Center may not be performing the conversion well. That certainly seems a plausible explanation, but my perception of jRiver is that they know what they are doing. However, I'll raise this issue on the jRiver forum and report back here.

oldaudiophile: by "background," I am referred to what has my primary attention. I am working at a drafting table with my primary attention directed to what I am working on there. The speakers have been aimed and the subwoofer adjusted for this spot using instrumentation.

tomic601: I haven't visited 2L yet but shall soon.

For those who are interested, here is my update, mostly empirical:

After researching the sample rate conversion capability of jRiver Media Center (MC) via query on the jRiver forum and researching related discussions there, I have arrived at a likely evaluation of my experience, from the following possibilities:

1) It has been suggested that the sample rate conversion of MC is substandard. The consensus I have researched does not support this suggestion, and MC users feel that it is very good. By default, SSRC sample rate conversion is enabled, with SoX being an optional method. There is some debate on which method is superior, but the MC publishers recommend SSRC as the default, while providing SoX as a checkbox alternative. There is considerable discussion there about the audible differences between the two, and apparently, there is none, whereas there is allegedly and inaudible measurable difference. But I don't know who measured it and what their capabilities were.

I have not been able to find any 3rd-party analysis of a comparison of the two methods. In my case, the default (SSRC) was active, and SoX was not enabled.

2) It has been suggested that digital audio is likely to sound its best when played back at its native rate. That has been my experience with other recordings beyond the scope of this thread, but in this case, the native rate is unknown. I don't know at what rate this digital recording of The Planets was made or mastered, and I don't know whether the rate of the release is at that native rate. HDTracks, from whom the files are downloaded, does not provide this data, and they make no claims to provide products in their native rates. (They "offer what the publisher sends them," they effectively informed me some time ago in response to a different query.) However, in my opinion, this suggestion is certainly plausible.

3) MC sample rate conversion is effective (which seems probable given their history and experience), and I can indeed hear the difference between 96kHz and 48kHz. Whether this is due to the accuracy of the data, or to the digital filters employed for each rate, I cannot say.

So, I have concluded, for myself, that the difference is indeed audible, and that difference may be a result of a combination of #2 and/or #3 above. I do not feel compelled to explore other comparisons (other players, other DAC's, SSRC/SoX ABX), so it is possible that I am not a very dedicated audiophile. At this time, I am content to identify and play files at their native rates as best as I can.

 

I have some Blu Ray concert discs that are inexplicably cut off at 48.  They are clearly inferior to their 96 bretheran