Is Digital Audio Transmission Analog? [video]

[JSmith]

From what I can tell GoldenSound is know for "interpreting" measurements in ways that speak to the subjective side of us.

I think what Darko is really open towards, is people who say things he'd like to hear

To go further here, the response by @amirm to John Darko is quite correct... I mean Cameron really doesn't have the experience or history in this field, currently working for a mortgage broker;

https://uk.linkedin.com/in/cameronoatley

...adapting to the challenges of lockdown by and monetizing my content on technical and economics subjects using new business models.

I'd suggest Darko would have more 'experience' in a way... as at least he has been an audio journalist since 2010, but one of which is Six Moons;

https://de.linkedin.com/in/john-darko-ab8869bb

John is an audio journalist/reviewer focused on delivering insight and professional integrity to an ever-expanding readership; he writes from a consumer perspective.

Both these people are in the "audio reviewer" field as a business model, plain and simple... Amir is not, which speaks volumes to me.


JSmith

 

[JiiPee]

I agree that a Raspberry Pi based streamer is so good from sq point of view, that spending more money on a fancy streamer does not provide any improvement, but I would actually go even further in my conclusion and state that the vast majority of modern DACs are also so good, that besides few bad apples, they are in practice indistinguishable form each other when it comes to sq. To a fairly large degree the same is valid also to modern solid state amplifiers. So, if one is keen on achieving a good sq, the logical thing to do is to spend the available money and effort to speakers, room acoustics and dsp.

 

[amirm]

Ok, but it's a business communication, Amir is formally asking/offering to appear on a Darko podcast. Unless there is more to the exchange than we've seen, he didn't request confidentiality.

My email to him was published as a "letter to the editor" or whatever he called it. That was not the nature of what I wrote him. I thought I was contacting him to offer myself as a guest on his show. The main reason and trigger for that was him constantly calling Cameron an expert in audio (measurement and their audible ramifications). He clearly is not so I was telling him that if he wanted experts, I was available to play that role, and my qualifications therein. I was not commenting on the specifics of his podcast so calling it a letter response is not proper.

FYI, I wrote a reply to Darko at the time. I was not going to post it but since he has post the first two exchanges, here it is:

----
Hello John. Thank you for the response. Didn’t know if these emails get to you or not.

I find your response indicative of complete misunderstanding. I said nothing about Cameron not knowing how to measure. I said and quote:

“Karman has no formal experience in signal processing, psychoacoustics, research into audibility of measurements, engineering design, etc.”

I said audibility of measurements. Not measurements themselves. Audibility requires extensive knowledge of psychoacoustics. I know of no professional and personal experience he brings to this field and his explanations on your show spoke to same.

Also, I had no intention of saying in relation to him should I have come on your show. He is not of interest to me. Making sure people understand what science and engineering of audio says, is. You had some excellent questions and I thought they deserve a more complete and proper answer as I live and breath this technology and have done so for decades.

You don’t know me so let me be very clear: I am at all times without emotions when I talk about audio. I am driven by facts and can ill afford letting emotions get in the way. You spoke of Danny. Just compare his videos about me and my answers in reverse. His is full of personal remarks. Mine is full of data, measurements, references, listening tests, etc. I have given two recommendations for his products out of four I have tested. If I was driven by any animosity, this would have never happened.

Finally, I have no intention of publishing your email to anyone. I don’t know why you think there is any value in me doing that. I offered to be on your show to talk about what I know. You seem to think that is about a personal fight so dare eclining [declining]. I am OK with that.

What I will do then is create various videos on some of the things you discussed and provide proper coverage of them. So I appreciate giving me those ideas.

Take care,
Amir

----

 

[Vacceo]

As an Australian who went to high school in the US, being asked about Austria goes with the territory. It's a reference to the Austrian corporal of course per @Vacceo's Godwin-ism and follow-up.

Keep in mind that Berlin in the last century has been a city full of spies (in truth, since Bismark), so you can add that to the list of con men.

Of course the answer is different. Erin comes across as a guy who can present his knowledge and experience without making every disagreement a cage fight. Amir, unfortunately, opens with a pointed attack on "Karman" and concludes with a veiled threat, so Darko pegs him as a nutter with an axe to grind. Which is a shame, it could have been a good podcast session.

I don't think that session would have happened, even if Amir had written a silk-gloved message. Darko has a history of bullshit claims on diverse topics such as cables or magic electronics.

 

[RandomEar]

Well this definition is Ambiguous. The point is many analog signals are meant to be decoded. FM transmission is the most obvious example. What you point out is that it's not an "audio" signal. and that it can be "represented" digitally, or mathematically. But "Analog" don't relate to audio. At the end of the day your only point is that it's a signal that is not meant to be listened to. But the signal itself. It's a waveform, it has a frequency, it has an harmonic content, it is subject to noise and distortion, it can be represented on a FFT, just out of the audio band. it has all the attributes of an analog signal. What you do with it afterward is not what define the signal itself. The signal is nothing else than a square wave with variable pulse width. It's only digital when you use it that way but "digital" is not an attribute of the said signal.

We are not talking about audio. I never said anything about "listening to". We are talking about analog or digital, nothing else. And nothing of what you said is relevant to the argument I made or invalidates it. Your seem to be misunderstanding my point.

I once again ask you to take a step back in your investigation of the signal. Square wave, frequency, pulse width - these are all irrelevant details to this discussion. What counts is the information, which is transported by the signal: If the information has an infinite number of levels, it is analog. If it is meant to represent 0 or 1 only, it is digital. That's it.

 

[PeteL]

We are not talking about audio. I never said anything about "listening to". We are talking about analog or digital, nothing else. And nothing of what you said is relevant to the argument I made or invalidates it. Your seem to be misunderstanding my point.

I once again ask you to take a step back in your investigation of the signal. Square wave, frequency, pulse width - these are all irrelevant details to this discussion. What counts is the information, which is transported by the signal: If the information has an infinite number of levels, it is analog. If it is meant to represent 0 or 1 only, it is digital. That's it.

OK, the information transported by the signal is digital yes. I never disputed that. It was never disputed by anybody in fact, that's a hard fact. The statement being debated is if the transmission of a digital information is analog. This transmitted signal indeed has an infinite number of level since it has a rise time, and noise.

 

[RandomEar]

OK, the information transported by the signal is digital yes. I never disputed that. It was never disputed by anybody in fact, that's a hard fact. The statement being debated is if the transmission of a digital information is analog. This transmitted signal indeed has an infinite number of level since it has a rise time, and noise.

I guess that's where we differ in how we categorize the signal: You say it's analog and may contain digital information. I would classify all signals which carry digital information as digital "by default". But I get your argument that the physical signal is in the analog domain - it's not an ideal 0/1 signal, but a real one with noise and such and it is not clearly 0 or 1 without being interpreted/decoded first.

But I also know of no signal type, which is by definition 0 or 1 without the necessity to interpret the signal level. Even light in Toslink signals needs decoding and there is a lower and higher threshold for when the decoded signal should be seen as 0 or 1. Due to this fuzziness in real world signals, I like to define their type (digital or analog) based on the information, which is carried in the signal and not by looking at the raw signal.

 

[JSmith]

Maybe a reasonable analogy or comparison for those struggling to understand the concept here is over the air TV.

Digital TV can use the same frequency bands as the old analogue TV, but the data being sent is digital and requires decoding by a digital tuner set top box.

The means by which the data is being transmitted and received is irrelevant to the nature of what is being transmitted.


JSmith

 

[Plcamp]

There are very expensive and technically deep tools from the likes of Cadence, Mentor Graphics and several others that exist only because there is no such thing as a digital signal.

It’s always analog, we just use it in a way that allows 1s and 0s to be detected in that analog signal. It only a question of whether or not you have done a good enough job controlling grounding, noise, reflections, terminations and timing that determines if the data rate you need is actually achieved with the error rate you can tolerate.

 

[Awsmone]

My email to him was published as a "letter to the editor" or whatever he called it. That was not the nature of what I wrote him. I thought I was contacting him to offer myself as a guest on his show. The main reason and trigger for that was him constantly calling Cameron an expert in audio (measurement and their audible ramifications). He clearly is not so I was telling him that if he wanted experts, I was available to play that role, and my qualifications therein. I was not commenting on the specifics of his podcast so calling it a letter response is not proper.

FYI, I wrote a reply to Darko at the time. I was not going to post it but since he has post the first two exchanges, here it is:

----
Hello John. Thank you for the response. Didn’t know if these emails get to you or not.

I find your response indicative of complete misunderstanding. I said nothing about Cameron not knowing how to measure. I said and quote:

“Karman has no formal experience in signal processing, psychoacoustics, research into audibility of measurements, engineering design, etc.”

I said audibility of measurements. Not measurements themselves. Audibility requires extensive knowledge of psychoacoustics. I know of no professional and personal experience he brings to this field and his explanations on your show spoke to same.

Also, I had no intention of saying in relation to him should I have come on your show. He is not of interest to me. Making sure people understand what science and engineering of audio says, is. You had some excellent questions and I thought they deserve a more complete and proper answer as I live and breath this technology and have done so for decades.

You don’t know me so let me be very clear: I am at all times without emotions when I talk about audio. I am driven by facts and can ill afford letting emotions get in the way. You spoke of Danny. Just compare his videos about me and my answers in reverse. His is full of personal remarks. Mine is full of data, measurements, references, listening tests, etc. I have given two recommendations for his products out of four I have tested. If I was driven by any animosity, this would have never happened.

Finally, I have no intention of publishing your email to anyone. I don’t know why you think there is any value in me doing that. I offered to be on your show to talk about what I know. You seem to think that is about a personal fight so dare eclining [declining]. I am OK with that.

What I will do then is create various videos on some of the things you discussed and provide proper coverage of them. So I appreciate giving me those ideas.

Take care,
Amir

----

Hmm
sounds like he knows your dangerous to his paradigm/business model, ie bottled water shouldn’t be measured ( funny enough it is for standard) and Cameron was a Trojan horse to show he is not scared of measurements .

he was looking for any excuse to brush you off

his videos are just infomercials , and I am disappointed he is from Australia at least he doesn’t live here anymore

 

[pma]

I guess that's where we differ in how we categorize the signal: You say it's analog and may contain digital information

No. He only says that the transmission path of the serial interface (S/PDIF, USB) is analog and that is absolutely correct. This path has limited bandwidth and may be affected by noises of different origin. Again, talking only about transfer path channel physical laser. Is it so difficult to understand?

 

[PeteL]

Maybe a reasonable analogy or comparison for those struggling to understand the concept here is over the air TV.

Digital TV can use the same frequency bands as the old analogue TV, but the data being sent is digital and requires decoding by a digital tuner set top box.

The means by which the data is being transmitted and received is irrelevant to the nature of what is being transmitted.


JSmith

I think that the point on this matter is what is "relevant" in the context of an audio science forum is what has some relevance in term of engineering, at least to me, that's how you treat this electrical signal. if at the end the whole point was to convince me that digital audio use binary states (or more) that need to be converted and analog audio transfer a fluctuating voltage that once amplified can push speakers without being converted, OK. I don't feel it's relevent to discuss that. I knew that when we got our first CD player at home 35 years ago, and I was 10 years old. Is that the point you guys have been trying to make all along?

 

[Vacceo]

Hmm
sounds like he knows your dangerous to his paradigm/business model, ie bottled water shouldn’t be measured ( funny enough it is for standard) and Cameron was a Trojan horse to show he is not scared of measurements .

he was looking for any excuse to brush you off

his videos are just infomercials , and I am disappointed he is from Australia at least he doesn’t live here anymore

He´s originally from the UK. His bio states that he grew up when Thatcher was prime minister. Too bad he didn´t pick up the spirit of the times listening to Crust Punk.

Maybe a reasonable analogy or comparison for those struggling to understand the concept here is over the air TV.

Digital TV can use the same frequency bands as the old analogue TV, but the data being sent is digital and requires decoding by a digital tuner set top box.

The means by which the data is being transmitted and received is irrelevant to the nature of what is being transmitted.


JSmith

I´d rather sound stupid for a second than belive stupid for years, so here it goes: why then switching to digital to send signals?

 

[PeteL]

I´d rather sound stupid for a second than belive stupid for years, so here it goes: why then switching to digital to send signals?

The carrier will always be RF, no antennas knows what to do with a pulse. Even if we are talking purely digital allocated bands like Wifi 2.4 GHz, it's still an analog signal. The benefit of encoding-decoding (Digital) vs modulating- demodulating (Analog) are numerous. You can get more information on a narrower bandwidth for a start, the frequency may be the same but you don't deal with cross modulations as much and interferences, as with digital audio, will only matter past a decision threshold, where in analog TV they are baked in with the signal. Your Analog TV signal will degrade, where your Digital TV signal will just cut off if interferences are high enough.

 

[JSmith]

why then switching to digital to send signals?

You may not have experienced analogue TV transmission... interference, ghosting, static, snow etc. DTV is a bit for bit exact transmission of the source. Multiple sub-channels are carried on one frequency instead of only one analogue channel taking up the whole bandwidth.

Understanding muxing

Multiplexing is a technique for carrying multiple channels of information within a common signal. Although usually thought of as a digital process, the

www.tvtechnology.com

Multiplex (television) - Wikipedia

en.wikipedia.org

JSmith

 

[Vacceo]

You may not have experienced analogue TV transmission... interference, ghosting, static, snow etc. DTV is a bit for bit exact transmission of the source. Multiple sub-channels are carried on one frequency instead of only one analogue channel taking up the whole bandwidth.

Understanding muxing

Multiplexing is a technique for carrying multiple channels of information within a common signal. Although usually thought of as a digital process, the

www.tvtechnology.com

Multiplex (television) - Wikipedia

en.wikipedia.org

JSmith

I´m old enough to have experienced test card signal broadcast between midnight and 6 a.m and channel dial wheels.
So, the logic for digital transmision is in the capacity to increase data sent (RDS in the case of digital FM radio) and to filter noise and other signal polution.

 

[JSmith]

I´m old enough to have experienced test card signal broadcast between midnight and 6 a.m and channel dial wheels.

Then like me you went from a dial, to buttons, then saw the birth of the wired 'remote' control and then IR remote control. I miss late night and early morning test patterns... were great for calibrating the ol' CRT TV's.


JSmith

 

[Vacceo]

Then like me you went from a dial, to buttons, then saw the birth of the wired 'remote' control and then IR remote control. I miss late night and early morning test patterns... were great for calibrating the ol' CRT TV's.


JSmith

Speaking of that and since there is a nice amount of tech insiders and specialists: do you guys think that FM and terrestrial TV broadcast will eventually dissapear?

I am asking this because DAB radio seems to not be as universal as expected while internet connection is becoming ubiquitous due to smartphones and internet of things. If the signal can be sent through the internet and its access is becoming so widespread, do you see the potential for DAB, FM and DTV to dissapear?

 

[JSmith]

do you see the potential for DAB, FM and DTV to dissapear?

Very much so, potentially... but this is very general as it depends on the country. Here in Aus we still have AM/FM, DAB+ also in some the main cities, no analogue TV left though, all DTV now. All main station channels are required to have an SD version of the channel for those that may have older TV's and tuners that can't do HD or MPEG4. Most of these services are now also available online, although there will always be some people (elderly, disabled, remote locations, not wealthy etc.) that will always need access to some free and cheap form of receiving national news services. Especially in our rural areas where bush fires, droughts and floods can be common. Of course personally I hope none disappear.


JSmith

 

[diddley]

I am proud of you Amir of the way you handeld your conversation with Darko.
It is clear that he don't want a critical person on his show.
Well don't be sad, his model of earning money wont hold up in the long run.
He is depended on the latest product, they give him and people will see through it.

This site (you) provides hard data for people to learn and put their buying decisions on.
What has more value?