What is 'incompetent digital' ?

[Opus111]

Now you've included plots you've given a good example of an incontinent DAC - the second one. Its putting out ultrasonic imaging products but they're not a modulated noise floor. They're likely to get turned into one in the next component in the chain though if there's some non-linearity (normally there is).

 

[March Audio]

I don't see any goalposts they must be a figment of your imagination.

How is changing from talking about noise floor modulation to ultrasonic spuria not moving the goalposts? The context of that part of the conversation was specifically noise floor modulation.

 

[March Audio]

Now you've included plots you've given a good example of an incontinent DAC - the second one. Its putting out ultrasonic imaging products but they're not a modulated noise floor. They're likely to get turned into one in the next component in the chain though if there's some non-linearity (normally there is).

I think you should re-phrase likely to possibly.

BTW, both those files are available for download in the other thread. Can you tell me which is which without loading them into a DAW?

 

[Opus111]

You made a specific claim, which was :

you must be making the assertion that current DAC noise floors (modulated) arent low enough

I provided an example which falsifies your claim - a DAC can have a low enough noise floor itself but still give rise to noise floor modulations in the system. Your MDAC's noise floor modulation I know nothing at all about but its incontinent so presents a system problem.

My point here is that noise floor modulation isn't just about DACs themselves. So if you were to replace 'DAC noise floors' with 'digital system noise floors' in your claim we'll be fine.

 

[Opus111]

I think you should re-phrase likely to possibly.

Why? Care to give reasoning why its not likely?

BTW, both those files are available for download in the other thread. Can you tell me which is which without loading them into a DAW?

What benefit might ensue to me from spending time on that?

 

[March Audio]

You made a specific claim, which was :

you must be making the assertion that current DAC noise floors (modulated) arent low enough

I provided an example which falsifies your claim - a DAC can have a low enough noise floor itself but still give rise to noise floor modulations in the system. Your MDAC's noise floor modulation I know nothing at all about but its incontinent so presents a system problem.

My point here is that noise floor modulation isn't just about DACs themselves. So if you were to replace 'DAC noise floors' with 'digital system noise floors' in your claim we'll be fine.

Yes, as we were specifically talking about noise floor modulation. You subsequently moved the goalposts to include ultrasonic spuria.

Well its one filter type that does this and secondly its not a given that its a system problem. That entirely depends on how the following component reacts. Hence why I suggested likley be changed to possible.

I think the issue here is you are making leaps and assumptions

 

[March Audio]

Why? Care to give reasoning why its not likely?



What benefit might ensue to me from spending time on that?

I think it is you that needs to explain why its likely and not just a possibility.

Benefit, well you are the one making statements regarding the effects of ultrasonic spuria. Here you have a definitive example. I thought it would be of very relevant interest for you. Its directly relevant to the thread you have created apparantly.

 

[Opus111]

Yes, as we were specifically talking about noise floor modulation. You subsequently moved the goalposts to include ultrasonic spuria.

Where did you get the notion that there are any 'goalposts' here? We're both free to talk about whatever's interesting to each of us.

Well its one filter type that does this and secondly its not a given that its a system problem.

Tilting at windmills - I've not claimed that its 'a given' so why even raise the possibility?

That entirely depends on how the following component reacts. Hence why I suggested likley be changed to possible.

Doesn't explain at all why 'likely' is the wrong choice of words. Its likely (overwhelmingly likely) that the next component is going to exhibit some non-linearity. So I take it your argument is merely one from authority.

 

[Opus111]

I think it is you that needs to explain why its likely and not just a possibility.

That's your opinion.

Benefit, well you are the one making statements regarding the effects of ultrasonic spuria. Here you have a definitive example. I thought it would be of very relevant interest for you. Its directly relevant to the thread you have created pparantly.

How are the ultrasonic spuria appearing in my file (bandlimited as it is to 22kHz)? They may be turned into noise floor modulation by your ADC I'll grant but as your ADC isn't something I'm at all likely to put into my system, its moot. Or your ADC may have inadequate anti-aliasing filtering, but that's of precisely zero interest to me.

 

[March Audio]

Where did you get the notion that there are any 'goalposts' here? We're both free to talk about whatever's interesting to each of us.



Tilting at windmills - I've not claimed that its 'a given' so why even raise the possibility?



Doesn't explain at all why 'likely' is the wrong choice of words. Its likely (overwhelmingly likely) that the next component is going to exhibit some non-linearity. So I take it your argument is merely one from authority.

It was the specific context of that part of the conversation.

Not a given but you said it was likely. Without specific evidence and reasoning its merely an assumption.

 

[Opus111]

I'm not claiming its necessarily an audible problem, but from an engineering perspective introducing ultrasonic spuriae is relatively poor form for the following equipment. That's my opinion of course and the degree of attenuation of ultrasonics is a matter of making engineering trade-offs.

 

[March Audio]

That's your opinion.



How are the ultrasonic spuria appearing in my file (bandlimited as it is to 22kHz)? They may be turned into noise floor modulation by your ADC I'll grant but as your ADC isn't something I'm at all likely to put into my system, its moot. Or your ADC may have inadequate anti-aliasing filtering, but that's of precisely zero interest to me.

Its not an opinion, its a logical conclusion. Without evidence you have no basis to say likely.

Your file was output from the dac and measured to a higher bandwidth. This is a side effect of the particular dac filter selected. The precise details you would need to ask the designer.

Its nothing to do with the ADC, its not there with other DAC filters. The adc aliasing filter is just fine.

Again you are just making leaps and assumptions. For someone who started a thread on the subject, I find it very odd to see you say its of no interest.

 

[March Audio]

I'm not claiming its necessarily an audible problem, but from an engineering perspective introducing ultrasonic spuriae is relatively poor form for the following equipment. That's my opinion of course and the degree of attenuation of ultrasonics is a matter of making engineering trade-offs.

I dont disagree with this. One of the tradeoffs with this particular filter is its a side effect to minimise pre-ringing. Some feel that is of benefit.

 

[Opus111]

Your file was output from the dac and measured to a higher bandwidth.

You've lost me with this word 'measured'. What do you mean?

Its nothing to do with the ADC, its not there with other DAC filters. The adc aliasing filter is just fine.

What does 'just fine' mean in engineering terms?

Again you are just making leaps and assumptions. For someone who started a thread on the subject, I find it very odd to see you say its of no interest.

You're making claim after claim. I don't find that at all odd though

 

[Opus111]

I dont disagree with this. One of the tradeoffs with this particular filter is its a side effect to minimise pre-ringing. Some feel that is of benefit.

I'm sure that no such trade-off exists between pre-ringing and stop band rejection. So perhaps you've misunderstood Mr Westlake's explanations at some point. Pre-ringing is solely connected with (a necessary side-effect of) the choice of making a filter phase linear.

 

[March Audio]

You've lost me with this word 'measured'. What do you mean?



What does 'just fine' mean in engineering terms?



You're making claim after claim. I don't find that at all odd though

? It means exactly what is stated.

Stopband is -100dB by 0.6 FS

I am not making any claims, I am attempting to get some clarity regarding your statements.

You have stated that noise floor modulation and latterly ultrasonic spuria affect your peception of dynamics.

I am just trying to progress this beyond these statements which are somewhat meaningless without some more objective evidence to support them.

At the moment you seem more interested in playing semantics than moving the thread you started forward.

 

[March Audio]

I'm sure that no such trade-off exists between pre-ringing and stop band rejection. So perhaps you've misunderstood Mr Westlake's explanations at some point. Pre-ringing is solely connected with (a necessary side-effect of) the choice of making a filter phase linear.

I didnt say anything about stopband rejection. I said the spuria were a tradeoff of this type of filter which has the property of reducing pre-ringing. The rest was your assumption.

 

[Opus111]

? It means exactly what is stated.

I've not heard the phrase 'measured to a higher bandwidth' before but I'd like some clarity from your statement. Is the 'measurement' you're referring to the picture you posted up showing imaging products? Based on what you've said before the DAC played out at 44k1 and the ADC digitized once again, at 44k1. Based on my observations from Audacity those two 44k1s were asynchronous. So where's the 'higher bandwidth' ?

I am not making any claims, I am attempting to get some clarity regarding your statements.

Oh look, another claim. Getting clarity would be best achieved by asking questions rather than making claims.

 

[Opus111]

I didnt say anything about stopband rejection.

Nor did you need to - I observed the deficiency in stop band rejection myself from your posted images. You haven't disagreed that the DAC's incontinent with that filter engaged either.

I said the spuria were a tradeoff of this type of filter which has the property of reducing pre-ringing.

That isn't what you said, fortunately the original is still there - 'a side effect to minimize pre-ringing' (italics my own).

 

[March Audio]

I've not heard the phrase 'measured to a higher bandwidth' before but I'd like some clarity from your statement. Is the 'measurement' you're referring to the picture you posted up showing imaging products? Based on what you've said before the DAC played out at 44k1 and the ADC digitized once again, at 44k1. Based on my observations from Audacity those two 44k1s were asynchronous. So where's the 'higher bandwidth' ?



Oh look, another claim. Getting clarity would be best achieved by asking questions rather than making claims.

It seems a perfectly normal and self explanatory term, to be precise, the measurement bandwidth was 48kHz as is clearly visible on the posted plots.

You may not have seen the additional files I placed on the other thread.

This is exceedingly tedious. Do you have any information to offer beyond your claim that noise floor modulation and ultrasonic spuria affect your perception of dynamics?