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TOPIC: DDRC 48/96khz resampling artefacts

DDRC 48/96khz resampling artefacts 2 months 3 weeks ago #29690

  • nugat
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Isn't resampling from a source 44.1kHz to 48/96kHz on DDRCdetrimental to sound quality?
Wouldn't it be better to keep processing at the same sampling rate as that of source materials?
TIA
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DDRC 48/96khz resampling artefacts 2 months 3 weeks ago #29712

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@ nugat

An interesting question. Without miniDSP getting into that hot debate, there is a HOST of very valuable info on how Sample Rate Conversion works. The post on DIY Audio by Werewolf is by far the most advanced from his background and well worth reading to understand what is Sample rate conversion.. :-)

www.diyaudio.com/forums/digital-source/2...rate-conversion.html

DevTeam
MiniDSP, building a DIY DSP community one board at a time.
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DDRC 48/96khz resampling artefacts 2 months 3 weeks ago #29717

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Thanks for the link, it's very informative especially for engineers . For people who are not electrical engineers (like me) rather above our heads.
My question was prompted by Dirac's recommendation to set the OS sampling rate (in case of the computer based Dirac) to the same
as source to avoid resampling. For Tidal/iTunes sources that usually means 44.1kHz. I was just wondering about hardware based Dirac, where the incoming data is 44.1kHz and the internal processing 48/96khz.
Last Edit: 2 months 3 weeks ago by nugat.
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DDRC 48/96khz resampling artefacts 2 months 3 weeks ago #29723

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Where does Dirac recommend that? (link?)
I am not miniDSP support.

"You must ask the right questions." - Dr. Alfred Lanning's hologram.
-> Have you read the User Manual??
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DDRC 48/96khz resampling artefacts 2 months 3 weeks ago #29726

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john.reekie wrote:
Where does Dirac recommend that? (link?)

In their FAQ 4.1 with an exclamation mark.
www.dirac.com/faq-technical

Dirac Audio Processor™ (DAP)
4.1. What sample rates does DAP support?
The DAP supports any sample rates up to 192 kHz which have been designed into the Dirac Live® filters. The sample rates designed into the Dirac Live® filters are selected by the user from the rates supported by the sound device used in the DLCT. However, to fully support a certain sample rate, then each of the blocks in the process line below have to support that rate. Note that the operating system can be configured to a different sample rate than the media player, making the operating system re-sample the data to its configured sample rate. This re-sampling can be detrimental to the audio quality! Try setting the operating system to use the original source sampling rate. User control over sampling rate is not possible in Windows XP.
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DDRC 48/96khz resampling artefacts 2 months 3 weeks ago #29727

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OK thanks.

I'm wondering about three questions essentially the same being posted in the last day or so by three different users.

Anyway, it seems to me that Dirac is saying that the OS may not have a very good sample rate conversion, not that sample rate conversion "per se" is bad.
I am not miniDSP support.

"You must ask the right questions." - Dr. Alfred Lanning's hologram.
-> Have you read the User Manual??
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Last Edit: 2 months 3 weeks ago by john.reekie.
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DDRC 48/96khz resampling artefacts 2 months 3 weeks ago #29731

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john.reekie wrote:
OK thanks.

I'm wondering about three questions essentially the same being posted in the last day or so by three different users.

Anyway, if you read the words, Dirac is saying that the OS may not have a very good sample rate conversion, not that sample rate conversion is bad.

Can't say for the other two users (haven't seen their posts) , but I am just trying to find out if Minidsp hardware sample rate conversion is also possibly "not very good" like MacOS/Windows or is it better. I would hope hardware should be better at this...
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DDRC 48/96khz resampling artefacts 2 months 3 weeks ago #29733

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I think it's done in the SHARC processor, not hardware.
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DDRC 48/96khz resampling artefacts 2 months 3 weeks ago #29734

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So instead of say MacOS/Intel there is some basic MiniDsp OS/firmware that does the resampling with the Sharc?
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DDRC 48/96khz resampling artefacts 2 months 3 weeks ago #29737

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I believe it's done in software on the SHARC, although devteam (the technical version) would have to confirm. I mean, in the end, you'd have to listen to it, or find something written by someone who has done some sort of reasonable comparison.
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DDRC 48/96khz resampling artefacts 2 months 3 weeks ago #29771

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According to the Datasheet the SHARC 21369 contains Hardware ASRC Blocks similar to the AD1896 SRC.
kind regards, Daniel
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DDRC 48/96khz resampling artefacts 2 months 3 weeks ago #29772

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curryman wrote:
According to the Datasheet the SHARC 21369 contains Hardware ASRC Blocks similar to the AD1896 SRC.
kind regards, Daniel

That would be good news as far as resampling, right?
In that scenario it would be better to leave all signal chain elements before minidsp at the original source rate.
Last Edit: 2 months 3 weeks ago by nugat.
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DDRC 48/96khz resampling artefacts 2 months 3 weeks ago #29833

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curryman wrote:
According to the Datasheet the SHARC 21369 contains Hardware ASRC Blocks similar to the AD1896 SRC.
kind regards, Daniel

Ah, so it does!
The sample rate converter (SRC) contains four SRC blocks and is the same core as that used in the AD1896 192 kHz stereo asynchronous sample rate converter and provides up to 128 dB SNR. The SRC block is used to perform synchronous or asyn- chronous sample rate conversion across independent stereo channels, without using internal processor resources. The four SRC blocks can also be configured to operate together to con- vert multichannel audio data without phase mismatches. Finally, the SRC can be used to clean up audio data from jittery clock sources such as the S/PDIF receiver.
I am not miniDSP support.

"You must ask the right questions." - Dr. Alfred Lanning's hologram.
-> Have you read the User Manual??
-> Have you drawn and posted a diagram?
-> Have you posted a screenshot?
-> Have you posted your config file?
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