How actually Audirvana works

[mkrzych]

Hello,

It is a question which bothering me for awhile. If I have settings like below and play file with 192kHz sampling rate which my DAC does not support and this sampling rate is not visible in Midi settings on my Mac, who actually did the reconversion to 96kHz (max of my DAC) - iZotope, Core Audio or my DAC?

 

The section on the screenshot called Forced Upsampling (set to None in my case) is only for upsampling or also for downsampling?

 

 

 

Thanks for your clarification.

[Musicophile]

Hello,

It is a question which bothering me for awhile. If I have settings like below and play file with 192kHz sampling rate which my DAC does not support and this sampling rate is not visible in Midi settings on my Mac, who actually did the reconversion to 96kHz (max of my DAC) - iZotope, Core Audio or my DAC?

 

The section on the screenshot called Forced Upsampling (set to None in my case) is only for upsampling or also for downsampling?

 

[ATTACH=CONFIG]12792[/ATTACH]

 

[ATTACH=CONFIG]12793[/ATTACH]

 

Thanks for your clarification.

To my unterständig, this also includes downsampling.

[mkrzych]

To my unterständig, this also includes downsampling.

 

So if I have it set up as None, the actual downsampling will be done by Core Audio not iZotope, which is the worst case right? Not having 192kHz enabled in Mini pane this signal won't be send to my DAC natively, but downsampled on Mac if I am not mistaken…

[Musicophile]

So if I have it set up as None, the actual downsampling will be done by Core Audio not iZotope, which is the worst case right? Not having 192kHz enabled in Mini pane this signal won't be send to my DAC natively, but downsampled on Mac if I am not mistaken…

I don't think so. I'd assume that Audirvana autmatically down samples or up samples (using its own izotope) when you are playing sample rates that your DAC doesn't support.

 

What is the display telling you? Normally on the lower left corner you should see the file format and on the lower right corner the format the DAC receives. In my understanding Audirvana completely avoids core audio's own resampling.

 

The difference for the "forced" upsampling option is that it also applies to sample rates that your dac would natively play. So for example you could, by selecting the forced upsampling to maximum, have even your redbook files upsample to 96khz instead of playing them natively.

[Musicophile]

If you want to be sure of what I assume above, why don't you simply try to play a 192khz file and play around with the Izotope advanced settings. If you hear a difference, it shows that Izotope is active.

[mkrzych]

I don't think so. I'd assume that Audirvana autmatically down samples or up samples (using its own izotope) when you are playing sample rates that your DAC doesn't support.

 

What is the display telling you? Normally on the lower left corner you should see the file format and on the lower right corner the format the DAC receives. In my understanding Audirvana completely avoids core audio's own resampling.

 

The difference for the "forced" upsampling option is that it also applies to sample rates that your dac would natively play. So for example you could, by selecting the forced upsampling to maximum, have even your redbook files upsample to 96khz instead of playing them natively.

 

Thinking that way when I have Forced Upsampling set up to None, when I play 176.4/192kHz files on the bottom right corner I can see 24/96. For 88.2kHz is also 24/96, but in this case I am not so sure if upsampling this particular rate to 96kHz won't screw up the sound quality.

 

Would be nice to be sure if A+ only uses iZotope if selected despite the Upsampling settings.

[mwheelerk]

Under Custom Settings you can specify the DAC sample rate for each native one. You can verify this in the Audivrana interface as music is playing. The native rate will show in the lower left of the screen and the rate sent to the DAC at the lower right. On my DAC I can verify these DAC rates received from Audivrana on its display also.

[mkrzych]

Under Custom Settings you can specify the DAC sample rate for each native one. You can verify this in the Audivrana interface as music is playing. The native rate will show in the lower left of the screen and the rate sent to the DAC at the lower right.

 

So even if I do not specify anything and leave upsampling settings to None, iZotope will downsample the file to my maximum DAC support, which is 96kHz?

 

So, again maybe upsampling 88.2kHz to 96kHz is not so good idea, what do you think?

[mwheelerk]

So even if I do not specify anything and leave upsampling settings to None, iZotope will downsample the file to my maximum DAC support, which is 96kHz?

 

So, again maybe upsampling 88.2kHz to 96kHz is not so good idea, what do you think?

No, if None is selected the iZotope is not active. One thing I noted is in the screen shot where it shows Active Audio Device it shows Built In Audio which indicates to me you are using the internal DAC from your Mac unless the connection you are using requires this selection in Audio Midi. I use a USB connection and my Bel Canto DAC is displayed as the Active Audio Device in that screen. Shouldn't it be showing your Beresford?

[mkrzych]

No, if None is selected the iZotope is not active. One thing I noted is in the screen shot where it shows Active Audio Device it shows Built In Audio which indicates to me you are using the internal DAC from your Mac unless the connection you are using requires this selection in Audio Midi. I use a USB connection and my Bel Canto DAC is displayed as the Active Audio Device in that screen. Shouldn't it be showing your Beresford?

 

I don't know, but I am using optical toslink, so I guess it shouldn't show my Beres.

[mwheelerk]

I don't know, but I am using optical toslink, so I guess it shouldn't show my Beres.

Do you see your DAC As a selection in Audio Midi? This may just be my lack of understanding of using Toslink. It may be a non issue.

[goldsdad]

I don't know, but I am using optical toslink, so I guess it shouldn't show my Beres.

 

 

Correct, "Built-in Output" should be shown when using TOSLINK. (The computer has no way of obtaining the external device's identity via the one-way TOSLINK output.)

 

 

[goldsdad]

So, again maybe upsampling 88.2kHz to 96kHz is not so good idea, what do you think?

 

Surely it's good if it sounds good to you, or it's bad if it sounds bad to you. How does it sound to you?

[mkrzych]

Surely it's good if it sounds good to you, or it's bad if it sounds bad to you. How does it sound to you?

 

Well, depending on the recording. It seems that upsampling (setting in the Custom tab) value to 96kHz sounds little bit lively with more air, but it's very subtle.

 

So, if I need to use iZotope, I shouldn't set the upsampling in A+ to None, but maybe instead of it use Custom and set for instance 88.2->96kHz, 192->96 and 176.4->96kHz where 96kHz is my DAC "native" sampling rate?

[goldsdad]

Well, depending on the recording. It seems that upsampling (setting in the Custom tab) value to 96kHz sounds little bit lively with more air, but it's very subtle.

 

So, if I need to use iZotope, I shouldn't set the upsampling in A+ to None, but maybe instead of it use Custom and set for instance 88.2->96kHz, 192->96 and 176.4->96kHz where 96kHz is my DAC "native" sampling rate?

 

 

Yes, use the Custom option, or if you simply want everything, including 44.1, resampled to 96 by iZotope, then just use the "Maximum sampling rate upsampling" option.

[Musicophile]

No, if None is selected the iZotope is not active.

I'm sorry, but how can you be so sure about this claim?

[phatoldsun]

There is an User Manual that explains a lot about "how actually Audirvana works." Audirvana>Help> User Manual.

 

Page 16 says this:

 

Sample Rate Conversion

 

Sample Rate Conversion happens when

- The audio device does not handle the audio track sample rate

- Upsampling is forced.

[mwheelerk]

I'm sorry, but how can you be so sure about this claim?

I'm incorrect what I stated. It was Forced Upsampling that I was thinking of.

[Musicophile]

There is an User Manual that explains a lot about "how actually Audirvana works." Audirvana>Help> User Manual.

 

Page 16 says this:

 

Sample Rate Conversion

 

Sample Rate Conversion happens when

- The audio device does not handle the audio track sample rate

- Upsampling is forced.

Thanks for clarifying. RTFM sometimes really helps :-)

[mkrzych]

There is an User Manual that explains a lot about "how actually Audirvana works." Audirvana>Help> User Manual.

 

Page 16 says this:

 

Sample Rate Conversion

 

Sample Rate Conversion happens when

- The audio device does not handle the audio track sample rate

- Upsampling is forced.

 

It states Upsampling, so also downsamplingdoes not happen in Audirvana when Upsampling is set to None?!

[Musicophile]

It states Upsampling, so also downsamplingdoes not happen in Audirvana when Upsampling is set to None?!

That doesn't make sense.

 

I think he just uses upsampling here as nearly of the options he provides (with the exception of the "custom" which was only added in a later version then the rest of the options) under the "forced upsampling" menu actually do increase the sample rate.

 

In a nutshell, as I correctly presumed above, whenever Audirvana needs to change the sample rate for whatever reason, it will do so using Izotope and not using CoreAudio, unless you ask it to do so by choosing CoreAudio in the "converter" drop down.

[mkrzych]

That doesn't make sense.

 

I think he just uses upsampling here as nearly of the options he provides (with the exception of the "custom" which was only added in a later version then the rest of the options) under the "forced upsampling" menu actually do increase the sample rate.

 

In a nutshell, as I correctly presumed above, whenever Audirvana needs to change the sample rate for whatever reason, it will do so using Izotope and not using CoreAudio, unless you ask it to do so by choosing CoreAudio in the "converter" drop down.

 

So, it means that even I have Forced Upsampling set to None, A+ will use iZotope ALWAYS when up/downsampling is needed. This also implicates, that in my case especially, when I am not sure if my DAC can natively support 88.2kHz would be better to not upsample it to 96kHz (only this sampling rate I can see in Audio Midi or in A+ drop down menus).

 

If all really true, I am not so much convinced…

 

P.S. Someone said that because of TOSLINK, Mac OSX don't know what is the real sampling rate supported by the DAC and choosing the 44.1/48/96kHz as it would be for its internal DAC.

[Jud]

So, it means that even I have Forced Upsampling set to None, A+ will use iZotope ALWAYS when up/downsampling is needed. This also implicates, that in my case especially, when I am not sure if my DAC can natively support 88.2kHz would be better to not upsample it to 96kHz (only this sampling rate I can see in Audio Midi or in A+ drop down menus).

 

P.S. Someone said that because of TOSLINK, Mac OSX don't know what is the real sampling rate supported by the DAC and choosing the 44.1/48/96kHz as it would be for its internal DAC.

 

Hi Krzysztof. Perhaps it's a communication barrier, but this seems to make things more complicated than they really are. A+ will I believe handle automatic switching of the sample rate - otherwise why would it show only certain sample rates available? My other question is this: I am reading what you say above (perhaps incorrectly) to say your DAC doesn't handle 88.2kHz sample rates. So why wouldn't you want to upsample to the rate it does handle, 96kHz?

[mkrzych]

Hi Krzysztof. Perhaps it's a communication barrier, but this seems to make things more complicated than they really are. A+ will I believe handle automatic switching of the sample rate - otherwise why would it show only certain sample rates available? My other question is this: I am reading what you say above (perhaps incorrectly) to say your DAC doesn't handle 88.2kHz sample rates. So why wouldn't you want to upsample to the rate it does handle, 96kHz?

 

Hello Jud,

Let's try to make things more clear:

1. I cannot see any possibility to choose 88.2kHz neither in Audio Midi nor A+ drop down menus in Custom settings.

2. I am using TOSLINK, so as it was said it is normal that I cannot see what actually my DAC can support natively. I know for sure it can handle up to 96kHz, but WM8716 documentation does not specify if 88.2kHz is supported by this chipset. Potentially it could be.

 

Questions are:

a) If I set up "Force Upsampling" to "None", will A+ automatically handle all sampling reconversions (up/down) using iZotope algs?

b) Not being sure about my DAC 88.2kHz sampling support I'd like to be sure about the above first.

 

BTW, upsampling from 88.2 to 96 is not so nice - at least mathematically…

[Jud]

Hello Jud,

Let's try to make things more clear:

1. I cannot see any possibility to choose 88.2kHz neither in Audio Midi nor A+ drop down menus in Custom settings.

2. I am using TOSLINK, so as it was said it is normal that I cannot see what actually my DAC can support natively. I know for sure it can handle up to 96kHz, but WM8716 documentation does not specify if 88.2kHz is supported by this chipset. Potentially it could be.

 

Questions are:

a) If I set up "Force Upsampling" to "None", will A+ automatically handle all sampling reconversions (up/down) using iZotope algs?

b) Not being sure about my DAC 88.2kHz sampling support I'd like to be sure about the above first.

 

BTW, upsampling from 88.2 to 96 is not so nice - at least mathematically…

 

Hi Krzysztof. Yes, that's clearer. Here are the answers (sorry this is all in one big paragraph, but my company turns off scripting in some browsers in what I think is a misguided attempt at security, which results in the Return/Enter key not working for replies on this forum): (a) If forced resampling is turned off, then A+ will resample only when needed, for example if there is 88.2 material that your DAC can't handle. A+ will use iZotope unless you tell it to use Core Audio in the Preferences. I like iZotope personally. If the resampling doesn't work as it is supposed to, you will be aware of it immediately, since you will hear no sound. (b) If you are very interested in whether the information you are receiving that your DAC doesn't support 88.2 over TOSlink is correct, perhaps you could try playback from iTunes alone with Audio Midi set to the 88.2 rate. But I would not be terribly worried about this. 88.2 -> 96 is really not a problem for a computer. I have tried both integer multiples and non-integer multiples when resampling, and I am not sure I hear any difference.