Re: [LAU] bit-transparent playback/recoding over AES using an RME 9632 card

From: Markus Seeber <markus.seeber@email-addr-hidden>
Date: Fri Nov 18 2016 - 21:13:24 EET

On 11/18/2016 07:26 PM, Markus Seeber wrote:
> On 11/18/2016 06:30 PM, Chris Caudle wrote:
>> On Fri, November 18, 2016 8:59 am, Tino Mettler wrote:
>>> Actually, a colleague of mine did exactly that in Windows, using
>>> another RME card.
>>>
>>> Here are example screenshots of the original and the recording:
>>>
>>> https://tikei.de/playback.png
>>> https://tikei.de/recording.png
>> That looks correct. Do you have pictures of your result?
>>
> And if you use audacity, could you zoom in far enough so the discrete
> sample values can be seen? Just generate a 440Hz square wave, that
> should be fine.
>

Oh and I just noticed, that care has to be taken when importing and
exporting audio from and into audacity.

If you generate a track at 48 KHz sample rate, make sure you global
settings are also set to 48 KHz or else your import/export gets screwed
and material gets resampled without warning, resulting in exactly the
pattern you have described.

I just stumbled over this, hell this is annoying.

So basically:
1. Edit -> Preferences -> Quality and set default sample rate and format
to what you need, probably 32 bit float 48KHz
2. Create a mono audio track
3. click on the little drop down menu on the top left of the track strip
and make sure that the correct rate and format is set.
4. generate the square wave
5. export the wav and make sure again, to select 32bit float pcm
6. import the exported file again, if it looks exactly the same, it was
done right.

Then with the exported file, do your tests again and let's see if it
wasn't just Audacity screwing up the whole measurement.
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Received on Sat Nov 19 00:15:01 2016

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