Auria Built in Sample Rate Conversion

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jsol
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Auria Built in Sample Rate Conversion

Post by jsol » Sat Nov 01, 2014 9:54 pm

Hi Rim,

I know this question has come up many times. Regarding sample rate conversion. Let's say I work in 24 bit 48k audio. I mix in 24bit 48k audio. I like to mixdown to stereo 24bit 48k. I like to master in a new project to conserve CPU. In the past I would create a new 48k 24bit project. I would mixdown my master to 16 bit but there was no option for 48k so the the end result would be 16bit 48k even with fab filter L set to 16bit dither. So, to correct this, when starting my stereo mastering project, I would create a new 44k mastering project. Obviously, coming from 24bit 48k, my imported stereo wav file would enter the project auromatically converting to 44k so my mastering project would be 24bit 44k. I recently created a mastering stereo project at 24bit 48k and mixed down to 16bit 44k with success.

My question is, have I been losing audio quality by creating the new mastering project at 44k and importing 48k converting to 44k automatically taking away some audio resolution? I've seacrched the web for this info but found nothing on this.

I would like to know since I am now able to keep the sample rate the same throughout the whole project up to the mastering stage and now convert down to 16bit 44k at mixdown without any inbetween Auria automatic sample rate conversion.

Thank you,

JSol.
Last edited by jsol on Sun Nov 02, 2014 4:04 am, edited 1 time in total.

jsol
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Re: Auria Built in Sample Rate Conversion

Post by jsol » Sun Nov 02, 2014 3:53 am

Never mind,

I think I found the answer to my question from Ozone's website.

:"To use Ozone for dithering, you must first manually disable any internal dithering applied by the hostapp. This prevents the two dithering signals from adding together and conflicting.

Then, because we don't want to process our file after dithering (we'll go over this next), we need to downsample to 44.1 kHz *before* we handle our dithering and bit-depth. So convert your mix down to 44.1 kHz, but leave the bit-depth at 32 or 24-bit.

Finally, load this final 44.1 kHz / 32 or 24-bit master in your host, load Ozone as an effect, and select the desired dithering settings in Ozone's "Loudness Maximizer" module. Then perform your final bounce and output to a 16-bit file."

I think this explains everything in a nutshell.

JSol.

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Re: Auria Built in Sample Rate Conversion

Post by lukebredin » Wed Nov 05, 2014 6:57 am

Hi there

I'm a mastering engineer so hopefully can answer your question for you (and that I have in fact actually read it right!!). It does look like you found out your own info. You defiantly want to sample rate convert before doing any dithering.

Now as to the sampe rate converter in Auria, I've not myself tested it but I am sure it is top notch. I have before used different sample rate converters in different DAWs and get same results. In terms of your work flow though I have suggestions/pointers. You will actually lose some fidelity in your audio file by doing what you are doing because you are mastering with a 44.1k file and not the 48k file. So that alone is losing fidelity as you lost information in the sampling down then processed the file. Most people wouldn't notice though ;)

But for the sake of archiving the highest resolution of your songs I would stick with 48k to master it, then bounce it out again, re import to a new 44.1k project, then dither to 16bit. But if you are exporting your mix to then master it in a new project, I would create a new project for mastering at 96k. I know people will say there is no point in up sampling as your only making the file bigger but there isn't any extra info to make the audio file a higher quality, which is true. But you are going to process the file again in mastering and digital plugins give a nicer warmer feel when processing at higher sampling rates. This has been proven by a top mastering engineer too (Bob Katz, a mega audiofile!!). So personally in your work flow I would export your mix, import to a 96k mastering project, master it, export it at 96k, re import to a new project at 44.1k and then just put dithering on it to dither down to 16bit. That will give you the highest quality audio in your work flow. In my studio I do a similar work flow but I have watch folders set up from Wavelab8.5 to do all the convert and dithering at different stages for me. But everything I get in, gets up sampled to 96k if not already at that resolution mastered, then all the down sampling and dithering after (all in there own stages, never at the same time).

Another note. 24bit dither. You are exporting a fair few times in your work flow and though the noise floor of a 24bit file is so low you can't hear it, truncating to 24bit (ie just bouncing a file out without dithering it) does create digital distortion which if you do once or twice to the same file you won't be able to hear but after a few more bounces the cumulative effect of the added digital distortion does become adiable in the end. So if your thinking well I am not truncating to 24bit as my file is already a 24bit file, which is a fair assumption, is wrong. Everytimr we use a computer to process audio (even something as simple as moving a fader), the audio file's word length (the bit rate) is increased to the internal word length of the computer. So in the case of Auria I think is 64bit now. If not it will be at least 32bit. So each time you bounce out to 24bit your just truncating (chopping off) the last bits to 24bit. So you should always use 24bit dither when exporting to 24bit to preserve the file and stop the accumulative effects of lots of truncating. The other thing you can do to combat this is just export your file to 32bit and use 32bit until you dither down at the end. So export your mix at 48k 32bit. Make a new 96k 32bit project, import your file which gets up sampled to 96k. Master your file, Export at 96k 32bit. Make a new 44.1k 32bit project and dither to 16bit to export for CD use. Then dither to 24bit for digital use.

I hope that all makes sense and is helpful.

If any of it doesn't make sense, let me know and I'll try to explain further.

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Tarekith
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Re: Auria Built in Sample Rate Conversion

Post by Tarekith » Wed Nov 05, 2014 9:18 am

You're mixing up processing precision with storage bit depths, two totally different things I'm afraid.

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Re: Auria Built in Sample Rate Conversion

Post by lukebredin » Wed Nov 05, 2014 11:15 am

Care to elaborate further? I have spoken about two parts in this so I may not have explained myself properly. Instead of just saying someone is wrong, would be nice if you explained why.

I spoke about bit depth of a file & what happenes when you bounce a file and the need for dithering. And I spoke about processing at higher sample rates so not sure what I have wrong here unless it's a terminology thing.

Thanks

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Tarekith
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Re: Auria Built in Sample Rate Conversion

Post by Tarekith » Wed Nov 05, 2014 12:42 pm

Just that Auria being a 64bit app has no impact on the bit depth of the audio processing, that's mostly just affects how much memory Auria can access (among other things). Here's a good summary that might help:

http://www.soundonsound.com/sos/nov10/a ... 64-bit.htm

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Re: Auria Built in Sample Rate Conversion

Post by lukebredin » Wed Nov 05, 2014 12:45 pm

Brilliant, thanks. I may have mixed something up there. I will defiantly take a look.

But the word length of audio does increase to 32bits when processed no matter what bit depth you started with as most DAWs run at 32bit internally. I might not be using the right technical terms here but I think you get what I mean. So when bouncing to 24bits you are still truncating.

Cheers

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Re: Auria Built in Sample Rate Conversion

Post by Tarekith » Wed Nov 05, 2014 2:14 pm

I knew what you meant, just that your reasoning behind why this is might confuse people if it was wrong.

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Re: Auria Built in Sample Rate Conversion

Post by jsol » Wed Nov 05, 2014 3:22 pm

@lukebredin,

I really appreciate your full and descriptive reply! I totally get what you are saying! The only thing I'm concerned about is if I wanted to create a new project with the already mastered high src project is dither part. Fab Filter Pro L is the only plugin that offers the dither option. Auria doesn't allow you to dither as a host daw therefore, if I wanted to use dither, I would have to slap the pro L plugin in the new project on the already mastered wav file to use dither. Is there a way to disable the Limiter portion on the Pro L?

Lastly, in regards to a different topic, Auria gives you the option to set the mixer at 64bit architecture summing. Therefore, I know it takes up more cpu resources however, would mixing at at 32 bit and then right before the mixdown, if I activate 64bit, would this improve head room an quality in the audio whether it is mixing or mastering? Would it be more beneficial to have 64bit activated in the beginning of the mix and or master?

Thanks,

JSol.

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Re: Auria Built in Sample Rate Conversion

Post by mtingle » Wed Nov 05, 2014 3:37 pm

you can active 64 mixing at the end as Auria is non-destructive. You'd only need to activate it when doing a mixdown.

If your thinking of dithering at the end why not try either final touch app or Mastering Audio app? both have a choice of dither options.

They can be used as IAA or standalone.

jsol
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Re: Auria Built in Sample Rate Conversion

Post by jsol » Wed Nov 05, 2014 3:44 pm

Nice reply, so activating 64 bit would improve my sound qualty? I do own that mastering app, just gotta remember to deactive the compression and eq etc that is defaulted in that app just to dither.

Thanks.

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Re: Auria Built in Sample Rate Conversion

Post by mtingle » Wed Nov 05, 2014 4:09 pm

yeah, with audio mastering (great app btw) I just make a preset with just the dither engaged. remember to reset the input section to 0db as this doesn't get saved in the preset.

I believe Rim said that he can't tell the difference between 32 and 64 bit mixer. neither can I, so I leave it at 32. I may turn it on for the final mix but only if I remember and can be bothered as it takes a-g-e-s. But technically there is a difference especially if you use a bunch of plugins that really push the headroom (I'm guessing).
Last edited by mtingle on Wed Nov 05, 2014 5:02 pm, edited 1 time in total.

jsol
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Re: Auria Built in Sample Rate Conversion

Post by jsol » Wed Nov 05, 2014 4:10 pm

Cool thanx!!

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Re: Auria Built in Sample Rate Conversion

Post by lukebredin » Wed Nov 05, 2014 5:01 pm

Tarekith wrote:I knew what you meant, just that your reasoning behind why this is might confuse people if it was wrong.
I think you think I am talking about something else. My reasoning isn't wrong. To be fair I wasn't very clear and did make an error on something I said but i wasn't talking about operating systems or apps being 64bit and being able to access more RAM etc.. I was talking about the internal DSP engines of DAWs. For instance Logic's is 32bit float as most DAW's is. Pro Tools HD is 48bit! When a programme processes audio its an unavoidable mathematical thing that the bit depth of the audio file gets increased to the internal engine of the DAW regardless of the original bit depth and the information gets spread across all of the bits. So in Logics case thats 32bit float etc etc... So all signals that go to 24bit (i.e. the real world) should be dithered as the files just get truncated. If you repeatedly bounce and re-import, process and bounce again to 24bit without dither eventually all the digital distortion and audio artefacts created by truncating become audible. So you should always dither a 24bit bounce. If your bouncing a file that your just going to re import and keep everything 'in the box' with mastering digitally then you can get round this by bouncing at 32bit. No truncation of the file, regardless of the fact you can't actually audition a 32bit file because the DAC will dither the signal on it's way out (well should do) but the file it self isn't truncated and you keep all the data. I was just suggesting to do that so that there isn't an accumulative effect of bad noise from bouncing to 24bits a few times without dither as he will be keeping the file digitally to master digitally. Hopefully that made what I was meaning clearer.
jsol wrote:@lukebredin,

I really appreciate your full and descriptive reply! I totally get what you are saying! The only thing I'm concerned about is if I wanted to create a new project with the already mastered high src project is dither part. Fab Filter Pro L is the only plugin that offers the dither option. Auria doesn't allow you to dither as a host daw therefore, if I wanted to use dither, I would have to slap the pro L plugin in the new project on the already mastered wav file to use dither. Is there a way to disable the Limiter portion on the Pro L?

Lastly, in regards to a different topic, Auria gives you the option to set the mixer at 64bit architecture summing. Therefore, I know it takes up more cpu resources however, would mixing at at 32 bit and then right before the mixdown, if I activate 64bit, would this improve head room an quality in the audio whether it is mixing or mastering? Would it be more beneficial to have 64bit activated in the beginning of the mix and or master?

Thanks,

JSol.
No problem mate. I would do all my mastering in the 96k project including my final compression/limiting of the file and bounce it out at 96k 32bits. Import that into a new project set up at 44.1k so it sample rate converts it, put the Pro-L plugin on and just engage the dither. I don't own the Pro-L plunging so don't know the names of the exact settings, but if you had all headroom settings and thresholds etc.. set to 0db then there would be no gain changes or extra limiting happening so it will just be dithering. Or as mtingle pointed out use one of the dedicated mastering apps. I am pretty new to music production on iOS devices so still testing the different apps out. Oh and to be clear the only reason I am saying to create these extra projects is so that the sample rate conversion without a doubt will happen before the dithering then!! Some people might say my workflow is long but in my studio its speed up by using watch folders, so I can do this sort of thing pretty quickly. As for the 64bit mixer, use it if you can, if not I wouldn't lose sleep over it.

jsol
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Re: Auria Built in Sample Rate Conversion

Post by jsol » Wed Nov 05, 2014 5:49 pm

Excelente!! I will try it out.

Last question, do you believe in analog summing? Will it make my mixes better? Is in the box sufficient in your opinion? Lest say 8 channel anaolg summing...?

Thanks

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