Can "Everything" be measured?

[musicapristina]

Hello, this is my first new post, and it's a genuine question.

Can "Everything" be measured?

First, I'm glad to avoid speaking in terms of "sounds good" or "sounds bad." I think the job of anyone creating audio reproduction gear should be accuracy. With this view ( and to oversimplify) the job of a DAC would then be what? To generate an analog electrical output perfectly matching the analog electrical input to the ADC (coming in from a mic, assuming we're not mixing or doing synthesizers or whatnot). Do we have consensus here?

When I consider Chaos Theory, I'm reminded that miniscule changes in the initial state can lead to wild macroscopic changes. When I consider an audio system, I'm reminded that there are tons of variables at play. So I wonder, what's the consensus here as to whether or not "all" values can be measured? And to what degree of accuracy can they be measured?

And if there's chaos involved (those pesky little electrons are good candidates) the initial measurements are all the more important.

I understand the frustration with "audiophile snake oil." On the one hand, it's no different than $100 cigars, $1000 bottles of wine or $1,000,000 cars. What people think, feel, want, and desire is shaped by the world around them.

[ I'm about to wrap up, and I was sincere that my question, which I acknowledge may seem loaded, is genuine ]

But can we really say, should we really say... with "scientific certainty"... that a set of measurements is a completely comprehensive way to describe a DAC? And if so, please can someone lay out what that set of measurements would be?

 

[pma]

Depends how you define “Everything”

 

[JustJones]

As far as the analog signal, you can measure what goes in the ADC and measure what comes out the DAC and compare the signal to see if Chaos grabbed it.

 

[Gorgonzola]

I believe everything can be measured, I'm not entirely sure we know how to measure everything, though.

 

[solderdude]

With this view ( and to oversimplify) the job of a DAC would then be what? To generate an analog electrical output perfectly matching the analog electrical input to the ADC (coming in from a mic, assuming we're not mixing or doing synthesizers or whatnot). Do we have consensus here?

Alas that's not how it works. The ADC/DAC chain is bandwidth limited. The task of the ADC is to sample an analog waveform at a steady rate.
The DAC task is to output a voltage that corresponds to the 'digitally described' value. Because these are merely points in time the second function of the DAC is to make a smooth transition between the sample values. This is done according to rules.

In practice, the analog signal (not a wave) at the input of the ADC should be closely the same to that what was once fed to the ADC but is bandwidth limited.

what's the consensus here as to whether or not "all" values can be measured? And to what degree of accuracy can they be measured?

All values can be measured. Of course at some point the inevitable noise floor creates deviations. Also on the playback side there is noise added to the noise that was also added on the ADC side. Noise in the digital chain is not added to the analog signal (that depends a bit on the jitter rejection)

But can we really say, should we really say... with "scientific certainty"... that a set of measurements is a completely comprehensive way to describe a DAC? And if so, please can someone lay out what that set of measurements would be?

There is amplitude and timing in the electrical signal.
Both can be measured far beyond audible thresholds. Of course uncertainties grow when noise starts to play a role or near the edges of time related measurements.

Alas 'magic' and 'imagination' and 'colorful audio related descriptions' like things such as 'air' can not be measured and are the descriptors used by folks that don't understand how electronics work and use that as an excuse to tell engineers they can't measure everything and demand the engineers put a 'number' on those aspects that also has to correlate to their flawed and subjective and highly influence-able minds.

 

[pma]

Individual preference cannot be measured (and it often changes with time and experience), so we have this debates forever.

 

[Speedskater]

It's 'differences' that can be measured. If two electronic components sound different, then that difference can easily be measured. For transducers like loudspeakers and microphones, there are often many measurement differences, it may be difficult to identify which differences are meaningful.

 

[Jimbob54]

53 pages of mostly circular debate on this https://www.audiosciencereview.com/...ngs-that-cannot-be-measured.20808/post-688995

 

[musicapristina]

@pma, I define "everything" the regular way. (depends on how I define 'regular', too)

I'm mostly looking to understand:

1. The measurements people find most valuable.
2. Whether one would expect to get the "exact same" set of these measurements every time a test was run on the same DAC. (If experiments aren't repeatable, then???)
3. Whether they think that set of numbers completely defines a DAC. (If so, then we'd have an objective score for reproductive accuracy)

What do people think about "measuring" a DAC's output by recording it with an ADC, then comparing that new .WAV file (F`1) with the original (F`0)? If we are to have faith in this idea that you can "measure everything," and do so "accurately", then the WAV File F`N should be equivalent to F0, no?

 

[Berwhale]

The measurements people find most valuable.

Start here: Audibility thresholds of amp and DAC measurements | Audio Science Review (ASR) Forum

 

[Dubesaur]

If you are asking if there is magic in electronics and audio, then the answer is no. There being no magic means that the performance of electronics is measurable and understood.

 

[KSTR]

What do people think about "measuring" a DAC's output by recording it with an ADC, then comparing that new .WAV file (F`1) with the original (F`0)? If we are to have faith in this idea that you can "measure everything," and do so "accurately", then the WAV File F`N should be equivalent to F0, no?

Go here: https://www.audiosciencereview.com/...dible-with-music-signals-some-examples.20886/
Examples 4 and 5 are exactly what you describe. There is some corrective processing involved that allows the direct subtraction of the original and recording to check the equivalence. Without this, the difference signal would be dominated by things that are totally irrelevant like ever so tiny frequency response and phase differences (those are simple 'linear' errors).

 

[musicapristina]

@Berwhale Thanks, perfect!!!

 

[musicapristina]

@Dubesaur I'm not seeking magic, just reality. Many audiophiles make and believe some interesting claims. Some people here (from what I've read so far) are similarly dogmatic / religious (with a little 'r') about today's science. Let's please all understand that we're merely working within the framework of today's science. It's subject to revision. To better paradigms. To new measurement techniques, new algorithms.

So as I've said above, I want to understand the current consensus around which measurements will tell you that a DAC is "accurate" or not.

 

[AdamG]

@Dubesaur I'm not seeking magic, just reality. Many audiophiles make and believe some interesting claims. Some people here (from what I've read so far) are similarly dogmatic / religious (with a little 'r') about today's science. Let's please all understand that we're merely working within the framework of today's science. It's subject to revision. To better paradigms. To new measurement techniques, new algorithms.

So as I've said above, I want to understand the current consensus around which measurements will tell you that a DAC is "accurate" or not.

I gave you room to prove that your intentions are legitimate or you were just Trolling. This last post is beginning to smell Troll like. You Sir are now on a short leash.

 

[solderdude]

What do people think about "measuring" a DAC's output by recording it with an ADC, then comparing that new .WAV file (F`1) with the original (F`0)? If we are to have faith in this idea that you can "measure everything," and do so "accurately", then the WAV File F`N should be equivalent to F0, no?

This is called nulling and is a quite common technique in electronics.
Here's a way to do that.
You can analyze the crap out of the results and even listen to the results when using music.

There are also folks who looped music a few times and you can ABX the original vs the nth generation. You can also do this yourself providing your gear is decent.

In electronics there is only is a voltage and time.

 

[Wes]

Answer to OP is unknown since listening tests have not been done that would establish what distortion additions, alone or in combination, can be detected by young, trained listeners.

For electronics, the likely answer is 'probably'

 

[KSTR]

So as I've said above, I want to understand the current consensus around which measurements will tell you that a DAC is "accurate" or not.

As explained, the loopback difference test. That is even more stringent as it tests the transparency of DAC and ADC.
In case of the RME ADI-2 Pro FSR, I also can share an anecdote (no blind test). Some guy had a Denafrips Ares II ("entry level" R2R DAC) and wanted to have it measured by me. While I was at it, I proposed a test with the RME inserted as a AD-->DA process after the Ares, as well as using the RME as DAC proper. The guy stated that the RME did not alter the sound character he was used to hear from his DAC, but when using the RME as DAC he found the magic was missing. So, the informal conclusion can only be that the RME is transparent as AD-->DA, thus also transparent as DAC alone. And the Ares just had some euphonic distortion or whatever that made the sound more pleasing to his ears.
Since I had told him the RME would be transparent he maybe just heard what I told him... no blind test, so no "hard data". If so, that simply does mean it's all irrelevant anyway, we hear what we want to hear...

 

[musicapristina]

If so, that simply does mean it's all irrelevant anyway, we hear what we want to hear...

Yes, there's a ton of psychology (in addition to psychoacoustics) at play in terms of "listening" to music. And for some, the warm glow of tubes or hiss and pop of the needle on the record set the right atmosphere.

I'm not looking for good sound (that's the job of performing artists and recording engineers), I want accuracy.

 

[musicapristina]

@AdamG247 I was kindly provided a few great links to use as a starting point to get up to speed with the mindset and methodologies of the forum. Those links directly answered my questions. (There's a lot of posts on this forum, I don't have time to read them all) So I think this question has been answered for me.

Soon I want to learn how to conduct my own tests, what gear, software, etc. do I need?

The other person could have suggested that he relies on Dynamic Range and Digital Input Linearity. Perhaps to him, those 2 measurements adequately / perfectly define a DAC, and allow 2 DACs to be compared. But instead they suggested that I'm looking for "magic."

I've seen a lot of people talk about "snake-oil" and "overpriced" and "magic" here. I've seen I2S dismissed not by data or measurements, but by the "fact" that the original I2S spec is for transporting digital audio around a PCB. Yet the same rigor is not applied to dismissing the usage of USB since USB was not "designed" for transporting audio to a DAC.

I felt insulted by the assumption that I'm looking for magic. I want to know how much science is enough to define a DAC.

We all have biases. I'm not being rude. I'm not being provocative. And I'm not trolling.

More importantly, at this point, I'm not really sure what to do with your warning.