Is offset audible in high-end systems?

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audioengr

Is offset audible in high-end systems?
« on: 16 Mar 2019, 09:20 pm »
Offset is the leading nulls and trailing nulls that enclose the music data in the total data record.  It seems logical that this should not matter for sound quality, only the data words themselves.

Maybe not so logical.... 

So I have made four test files available here that all have identical music data fields, but different offsets, so you can see if you can hear any difference in your system.  It is interesting to determine if there is any DAC or re-clocking sensitivity here, so please list your DAC and if you use a re-clocker or if the DAC has a re-clocker inside being used. Also please list the playback software you are using.

The files include two 16/44.1 files and two 24/96 files of the same track.  It is a piano track.  I will not tell you yet which tracks are untouched and which have more nulls inserted into them. 

Download the four tracks here:

https://www.dropbox.com/sh/g9jz9lwgvozepic/AADx1d8YLCr5YCPQl23fUkFDa?dl=0

I would like anyone interested to listen to these tracks and report back on what they hear, describing things like dryness, ringyness, attack, decay, warmth, depth or shallowness of soundstage, clarity, wooliness etc. with each of the four tracks and rate them 1-4 with 1 being the most live sounding and 4 the least.

PS: I suspect that this might be one of the reasons that one playback software sounds different from another, or differences between one release and the next.

Thanks for your help,
Steve N.
Empirical Audio


audioengr

Re: Is offset audible in high-end systems?
« Reply #1 on: 17 Mar 2019, 09:00 pm »
bump

Wind Chaser

Re: Is offset audible in high-end systems?
« Reply #2 on: 17 Mar 2019, 09:43 pm »
I’m really looking forward the results and I hope there’s lots of participation. As for myself I wish I could participate but my system is down and if that weren’t bad enough, my internal SN has been severely compromised in recent months. If you could engineer a noise cancelling device for tinnitus, that would be awesome.  :D

audioengr

Re: Is offset audible in high-end systems?
« Reply #3 on: 18 Mar 2019, 06:06 pm »
I’m really looking forward the results and I hope there’s lots of participation. As for myself I wish I could participate but my system is down and if that weren’t bad enough, my internal SN has been severely compromised in recent months. If you could engineer a noise cancelling device for tinnitus, that would be awesome.  :D

I have a bit myself in one ear.  The best solution I have found is to lower distortion.  With my latest DAC I have found that I can listen at much higher levels without any ringing occurring.  It's distortion as well as amplitude that evidently causes this for me.

zoom25

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Re: Is offset audible in high-end systems?
« Reply #4 on: 18 Mar 2019, 09:13 pm »
I'll give it a go. :thumb:

audioengr

Re: Is offset audible in high-end systems?
« Reply #5 on: 20 Mar 2019, 12:10 am »
Come on folks.  Give these tracks a listen please.

mikeeastman

Re: Is offset audible in high-end systems?
« Reply #6 on: 20 Mar 2019, 02:08 am »
I downloaded the files and want to make sure I got them all. I got 4 different files a 1, 1a, 2, and 2a all wav files.  I should have time later in the week to give them a listen.

Mag

Re: Is offset audible in high-end systems?
« Reply #7 on: 20 Mar 2019, 04:44 am »
Okay I gave it a shot. The longer I listened the more uncertain I became of differences.

Listened with Windows Media Player on i7 computer, usb to BDA-1, SP2 internal dac, mixer, Bryston SST2, Model T passive speakers and approx 92 decibels.

Differences between the tracks were subtle.

Frame 1 seemed to be sterile sounding but accurate, Rated it 4

Frame 1a sounded fuller with more harmonics, seemed softer with some ringing of the notes. Rated it 2 guessing 16/44

Frame 2 seem fuller sounding similar to 1a ringing of notes seemed more sustained. Rated it 1 guessing this is the 24/96

Frame 2a seemed similar to frame 1 guessing it to be 24/96. Rated 4

audioengr

Re: Is offset audible in high-end systems?
« Reply #8 on: 20 Mar 2019, 03:49 pm »
I downloaded the files and want to make sure I got them all. I got 4 different files a 1, 1a, 2, and 2a all wav files.  I should have time later in the week to give them a listen.

That's all of them, 4 files.

audioengr

Re: Is offset audible in high-end systems?
« Reply #9 on: 22 Mar 2019, 06:06 pm »
Please folks, I need more feedback on this.  I need enough reports back to make the results significant so we can all learn something from this.

Aren't you curious as to why different playback software sounds different?  Why different rippers can sound different?  Maybe even different DACs?

This is what I'm trying to pinpoint.  The smoking gun.

audioengr

Re: Is offset audible in high-end systems?
« Reply #10 on: 23 Mar 2019, 04:52 pm »
bump

Doublej

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  • Posts: 2687
Re: Is offset audible in high-end systems?
« Reply #11 on: 23 Mar 2019, 11:03 pm »
Offset is the leading nulls and trailing nulls that enclose the music data in the total data record.  It seems logical that this should not matter for sound quality, only the data words themselves.

Maybe not so logical.... 

So I have made four test files available here that all have identical music data fields, but different offsets, so you can see if you can hear any difference in your system.  It is interesting to determine if there is any DAC or re-clocking sensitivity here, so please list your DAC and if you use a re-clocker or if the DAC has a re-clocker inside being used. Also please list the playback software you are using.

The files include two 16/44.1 files and two 24/96 files of the same track.  It is a piano track.  I will not tell you yet which tracks are untouched and which have more nulls inserted into them. 

Download the four tracks here:

https://www.dropbox.com/sh/g9jz9lwgvozepic/AADx1d8YLCr5YCPQl23fUkFDa?dl=0

I would like anyone interested to listen to these tracks and report back on what they hear, describing things like dryness, ringyness, attack, decay, warmth, depth or shallowness of soundstage, clarity, wooliness etc. with each of the four tracks and rate them 1-4 with 1 being the most live sounding and 4 the least.

PS: I suspect that this might be one of the reasons that one playback software sounds different from another, or differences between one release and the next.

Thanks for your help,
Steve N.
Empirical Audio

Can you explain this in more detail? Is a data word a 8, 16, 32, or 64 bit packet? Do I have thousands per song? Why do you think it might make a difference?

audioengr

Re: Is offset audible in high-end systems?
« Reply #12 on: 23 Mar 2019, 11:51 pm »
Can you explain this in more detail? Is a data word a 8, 16, 32, or 64 bit packet? Do I have thousands per song? Why do you think it might make a difference?

Data sub-frames are 32 time slots.  There is a 4 bit sync preamble, followed by 4 bit aux.bits followed by 24 bit audio word, followed by validity flag bit, user data bit, channel status bit and finally a parity bit.

Many subframes are put together to form a music track. This is about the structure of that track and how many leading and trailing nulls there are on either side of the music data.  These are microseconds of silence, so you don't notice that.  Adding 200 nulls to 2 thousand nulls should not make any difference, but that is what this test is for.

There are subtleties in S/PDIF protocol, such as stuffing and bursting that may be affected by changes in the offsets.

audioengr

Re: Is offset audible in high-end systems?
« Reply #13 on: 24 Mar 2019, 06:02 pm »
offset is a fixed thing, but evidently can vary from track to track.  It has to do with the track or many frames, not the sub-frame format.

I could not find anything on "offset" specifically, but in the 60958 spec. it defines "block structures":

"in 2-channel operation mode, the samples taken from both channels (L and R) are transmitted by time multiplexing in consecutive sub-frames.  The first sub-frame (left channel in stereophonic operation) normally starts with preamble "M".  However, the preamble changes to preamble "B" once every 192 frames to identify the start of the block structure used to organize the channel status information. The second sub-frame (right channel in stereophonic operation) always starts with preamble "W".

"Preambles are specific patterns providing synchronization and identification of sub-frames and blocks.  To achieve synchronization within one sampling period and to make the process completely reliable, these patterns violate the bi-phase-mark code rules, thereby avoiding the possibility of data imitating the preambles.

A set of three preambles is used.  These preambles are transmitted in the time allocated to four time slots at the start of each sub-frame  (time slots 0 to 3)…"

So, it is possible to mess-up the block by not changing the preamble correctly every 192 frames.  This would make it unclear when the data actually starts because the channel status would be misinterpreted.

I also found some things about "stuffing the subframe" to fill any unused capacity in sub-frames or "stuffing" to fill any unused data "capacity" of the interface.  Not sure if these apply.

WGH

Re: Is offset audible in high-end systems?
« Reply #14 on: 24 Mar 2019, 09:28 pm »
That is a hard test, it all comes down to guessing which means the changes are extremely slight, maybe solo piano where all the notes overlap and run together isn't the most revealing material.

My DAC is a Van Alstine Fet Valve Hybrid, I don't think it re-clocks. Software is the latest JRiver 64bit running on a custom built server that includes a Paul Pang USB card with linear regulated power supplies on the USB card and SSD. The USB to SPDIF converter is an upgraded Kingrex UC192 with it's own linear power supply. The custom JMaxwell Data Only USB cable contains only 3 wires, data plus, data minus and a ground wire, it does not have a 5v. lead. Speakers are Salk HT2-TL with RAAL tweeter.

I downloaded the tracks and converted to .flac with dBpoweramp so I could tag the tracks, that way I could use Gizmo remote to switch tracks from my couch. All my files are flac, high res downloads are flac so this is a more real life test.

By looking at file size and properties it was easy to see which files are 24/96. I listened to the tracks before looking and my impressions didn't change.
1 and 1a sounded like the original recording, 1a might be more revealing.
2 seems to have more ringing/janglyness
2a is a little smoother than 2 but the overhang still is there.

Overall the original recording seems to have some intrinsic distortion built in (tape saturation?) that makes it harder to listen through.
I wouldn't be surprised to find out all the tracks are identical and my street cred drops to "0".

Wayne

audioengr

Re: Is offset audible in high-end systems?
« Reply #15 on: 24 Mar 2019, 09:34 pm »
That is a hard test, it all comes down to guessing which means the changes are extremely slight, maybe solo piano where all the notes overlap and run together isn't the most revealing material.

My DAC is a Van Alstine Fet Valve Hybrid, I don't think it re-clocks. Software is the latest JRiver 64bit running on a custom built server that includes a Paul Pang USB card with linear regulated power supplies on the USB card and SSD. The USB to SPDIF converter is an upgraded Kingrex UC192 with it's own linear power supply. The custom JMaxwell Data Only USB cable contains only 3 wires, data plus, data minus and a ground wire, it does not have a 5v. lead. Speakers are Salk HT2-TL with RAAL tweeter.

I downloaded the tracks and converted to .flac with dBpoweramp so I could tag the tracks, that way I could use Gizmo remote to switch tracks from my couch. All my files are flac, high res downloads are flac so this is a more real life test.

By looking at file size and properties it was easy to see which files are 24/96. I listened to the tracks before looking and my impressions didn't change.
1 and 1a sounded like the original recording, 1a might be more revealing.
2 seems to have more ringing/janglyness
2a is a little smoother than 2 but the overhang still is there.

Overall the original recording seems to have some intrinsic distortion built in (tape saturation?) that makes it harder to listen through.
I wouldn't be surprised to find out all the tracks are identical and my street cred drops to "0".

Wayne

Thanks for doing this, but conversion to FLAC really invalidates your results.  FLAC itself causes changes in the sound quality.  Need to have your wife or a friend switch between the two .wav files.

The smaller files are actually the 24/96 versions.

WGH

Re: Is offset audible in high-end systems?
« Reply #16 on: 24 Mar 2019, 10:47 pm »
OK, I'll try it again.

Quote
The smaller files are actually the 24/96 versions.


That's tricky. How did you do that? Then when we download music and the file says 24/96 it really might not be. Here are two of wav files I downloaded:


   




audioengr

Re: Is offset audible in high-end systems?
« Reply #17 on: 24 Mar 2019, 11:02 pm »
OK, I'll try it again.


That's tricky. How did you do that? Then when we download music and the file says 24/96 it really might not be. Here are two of wav files I downloaded:


   

Verified it.  frame1 and frame 2 are 16/44.1, frame1a and frame 2a are 24/96.  Thanks for catching this. I assumed this guy was right and I think he just made a typo... Broke my own rule to never assume anything. :duh:

audioengr

Re: Is offset audible in high-end systems?
« Reply #18 on: 27 Mar 2019, 11:59 pm »
I would like to get more feedback, but I think I have enough to make some conclusions. Here is the raw data:

1) Mag

Okay I gave it a shot. The longer I listened the more uncertain I became of differences.

Listened with Windows Media Player on i7 computer, usb to BDA-1, SP2 internal dac, mixer, Bryston SST2, Model T passive
speakers and approx 92 decibels.

Differences between the tracks were subtle.

Frame 1 seemed to be sterile sounding but accurate, Rated it 4

Frame 1a sounded fuller with more harmonics, seemed softer with some ringing of the notes. Rated it 2 guessing 16/44

Frame 2 seem fuller sounding similar to 1a ringing of notes seemed more sustained. Rated it 1 guessing this is the 24/96

Frame 2a seemed similar to frame 1 guessing it to be 24/96. Rated 4

2) paul79

I have not had time yet to pick these apart all the way, but I find frame 2 to be the best of the bunch on my system.
It has longer decay, more impact, more weight, more body, strings ring better, and her moaning throughout is more obvious.
Very fluid and emotional. This last aspect especially, is not translated as well with the other versions.

2a was immediately dry sounding.

3) BYRTT

FRAME1=2
FRAME2=3
FRAME1a=2
FRAME2a=4

FRAME2/FRAME1a sounds fine, but its like recording microphone is more close/hot which is not as natural as a normal listening
seat several meters away and therefor lacks that natural room ambience, FRAME1/FRAME2a have this better difuse ambience that
sounds as recording microphone distance is more natural to a listening seat some meters away which in my ears give a better
natural sound, more difuse pleasing and tiny bit less resolution on notes than FRAME2/FRAME1a.

Playback software v23 64bit JRiver / R128 algorithm volume leveling / Equal loudness ISO226-2003 calibrated / track material
rates are played native over WASAPI 32bit to Khadas Tone Board DAC. Tranducer domain for test was using head phones well a
Neaurochrome HP-1 amp and DSP corrected HD650 cans.

4) cat6man

1=frame1
2=frame1a
3=frame2
4=frame2a

1 and 3 are 44.1k
2 and 4 are 96k

in my test, 1 >> 3 and 2 >> 4

frame 1 and frame 1a are best, frame 2 and frame 2a are worst

WAV files on QNAP nas ==> hqplayer embedded (no processing at all) on ubuntu NUC ==> NAA on cubox in totaldac ==> totaldac
re-clocker ==> totalDAC d1-direct

reclocker is usb in, aes/ebu out to dac

5) Rocoa

I've listened the four tracks right now (eyes closed) some times and the difference is clearly audible.
The system is: Jeff Rowland Aeris DAC, Corus preamp (+PSU), Model 625 S2 power amp., Avalon speakers, Cardas Clear and
Clear Beyond cables. As source an MacBook Air. Tellurium Q Black USB cable (very analog like and time coherent cable).
Between Aeris and USB cable an iFi iPurifier 3. Audirvana Plus.

Well, the most live sound track to me is, no doubt, track 4. I can listen much better the decays, and the piano's wood.
More ambience and harmonics, more body and depth, better image, perhaps less attack than previous one, but a more relaxed
and natural sound to my taste. The worst is the first track 1. The sound is more artificial, mechanic, edgy (less like a
grand piano, like a clavecin as overstatement).

So, my preferences: 4, 3, 2, 1 (2a, 2, 1a, 1).

Best - frame 2a
 ----  frame 2
 ----  frame 1a
 ----  frame 1

6) WGH

My DAC is a Van Alstine Fet Valve Hybrid, I don't think it re-clocks. Software is the latest JRiver 64bit running on a
custom built server that includes a Paul Pang USB card with linear regulated power supplies on the USB card and SSD.
The USB to SPDIF converter is an upgraded Kingrex UC192 with it's own linear power supply. The custom JMaxwell Data Only
USB cable contains only 3 wires, data plus, data minus and a ground wire, it does not have a 5v. lead. Speakers are
Salk HT2-TL with RAAL tweeter.

I downloaded the tracks and converted to .flac with dBpoweramp so I could tag the tracks, that way I could use Gizmo
remote to switch tracks from my couch. All my files are flac, high res downloads are flac so this is a more real life test.

By looking at file size and properties it was easy to see which files are 24/96. I listened to the tracks before looking
and my impressions didn't change.

1 and 1a sounded like the original recording, 1a might be more revealing.
2 seems to have more ringing/janglyness
2a is a little smoother than 2 but the overhang still is there.

7)Me

1) frame2
- Deep soundstage
- Not "ringy"
- Very focused
- Good attack and decay

2) frame2a
- Deep soundstage
- Not "ringy"
- Crisp attack
- Good focus
- Good decay
- A bit duller sound quality

3) frame1a
- Kind of "ringy", like sustain pedal down
- 3-D effect, but may be contrived
- Attack a bit muted
- Warm sounding
- Deep soundstage
- A bit less focused

4) frame1
- Up close, not as much depth or venu echo
- Good attack
- A bit wooley
- Poor focus

8) My wife

1) frame2
- Deep soundstage
- Not "ringy"
- Clean trills
- Notes don't run into each other
- Brighter overall sound quality

2) frame2a
- Not "ringy"
- A bit duller sound quality
- Sounds like damper pedal is down

3) frame1a
- Kind of "ringy", like sustain pedal down
- Warm sounding
- Deep soundstage
- A bit less focused

4) frame1
- Poor decay
- Dry sounding
- Boring

9) only one respondent did not hear any difference in any of the tracks.

--------------------------------------------------------------------------------------------------------------------------

Parsing the data:

Frame 1:   ratings: 4,4,2,4,1,3,4 - average is 3.14

Frame 1a: ratings: 3,3,1,3,2,2,2 - average is 2.28

Frame 2:   ratings: 1,1,4,2,4,1,1,1 - average is 1.875

Frame 2a: ratings: 2,2,3,1,3,4,3 - average is 2.57


Therefore, this puts the tracks in order from best to worse:

Frame 2 - best ---------------this is the 16/44.1 original
Frame 1a        ----------------this is the 24/96 modified
Frame 2a        ----------------this is the 24/96 original
Frame 1 - worst --------------this is the 16/44.1 modified

The only discrepancy is the middle two, because the order should have been:

Frame 2 - best
Frame 2a
Frame 1a
Frame 1 - worst

It tells me that maybe the upsampling software that was used to get the 24/96 file was not very good.

Conclusions:  It's a small data set and yet the results are fairly consistent. 

1) Pretty much everyone hated Frame 1 and most liked Frame 2.  These were the 16/44.1 tracks.

2) only 1 in 9 did not hear differences, although one said it was subtle.

3) 88.9% of these respondents heard a difference when comparing the original track to one with 200 offset nulls removed from the preamble and added to the postamble.

Steve N.





artur9

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  • Posts: 468
Re: Is offset audible in high-end systems?
« Reply #19 on: 29 Mar 2019, 12:25 am »
What upsampler did you use?

Also, my signal chain would be original -> upsampled with SoX (iirc)-> Gumby.  Would that upsampling invalidate the test?