Does Offset change sound quality?

[Empirical Audio]

Offset is the leading nulls and trailing nulls that enclose the music data in the total data record of any track at any sample-rate. 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

 

[Empirical Audio]

Here is a post from a technical expert in Germany that maybe explains it:

"KSTR of Berlin, Germany:
I've tested a cheap bus-powered USB ADC/DAC in loopback with only the packeting being different
and got a pretty huge difference in the residual, and that was pretty nolinear. The different
input data stream packeting had affected the internal voltage references/clock, led to different
rails/gnd pollution, some unknown things along this line caused measurable distortion in the
difference when measuring some 40dB down below the analog noise floor, very repeatable.
The device tested was a TASCAM US144 Mk.II. With that one (not HiFi by any standard) the
modulation is there. I've tested this with two different units (happen to have two of them and
a US122 Mk.II, as well) and in a series of experiments to make sure what I'm seeing is correct.
It's real. But, mind you, it's only visible once you climb below the analog noise floor.
This effect is also seen with the RME, though to a much lesser extent because the analog filters,
notably the high-passes, are at lower (or higher, for low-passes) frequencies, plus the clock seems
to have a better absolute long-term stability. With this test I also see that the clock in the RME
needs about 1 hour to settle, that is, until thermal equalibrium in the device is reached (it get's
hot, that thing). This shows the extreme resolution that can be had from heavy time-domain
block-averaging.
It is extremely hard to see this effect in standard measurements. Take your typical 1kHz sine test
or 19+20Khz IMD. The "packeting error" affects the dominant regular distortion only very slightly
(and it averages out, typically) plus any changes are covered by deviations just alone from the
analog noise floor.
This type of error can only be isolated with heavy block-averaging, and a pre-requisite is 100%
sample-synchronous record-while-playback. With the AP or a DSO and a trigger signal on the other
channel one can use block-averaging on non-synced streams as well, but any trigger jitter/uncertainty
causes high-frequency roll-off. RME have used this technique to verify the bit error I found in
their firmware and that I could display in a spectacular clarity (measurement noise floor way below
the LSB of 24 bits). This error, for example, is outside the measurement resolution of the typical
"standard tests", using the latest AP or what have you. More elaborate techniques have to be used."

 

[Empirical Audio]

This would really help with the science and understanding of these digital effects.

 

[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.

I will revisit this when I have time. Nonetheless, a very nice sounding track and interesting experiment. Others should give it a try.