Upsampling Filter Settings

Hello all

Quick question, does anyone know where I can find the original 'factory" settings for the upsampling filters? I’ve spent a lot of time adjusting them and get the fact that I should use my ears to decide but I can’t find the original settings.

Whilst I’m here does anyone have any advice around upsampling into a non-oversampling dac please? I’m using a Mac Mini going into a Lab12 SE dac.

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this should be it, as i don’t use them and i started from scratch this Christmas.

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Amazing thank you. This is greatly appreciated.

What is the point of these options? Assuming one has a decent dac to start with what improvements are claimed to be achievable by tweeking these knobs? Is it just up to us to try different settings and check for improvements or otherwise?

Also I thought the upsampling was done by the dac unless it is a NOS Dac? Mine does up to X8 upsampling I think…

That is a complex subject and not easily answered. There are lots of pro’s and cons with upsampling in software (music player program on a pc) vs hardware (DAC). The processors in DACs tend to have not much horse power so generally use very simple and crude upsampling methods. The processor in a computer like a pc or Mac is usually much more powerful and can use more sophisticated methods and filters.

There are also lots of different algorithms to upsample/resample (for example those used by SoX and r8brain) and each have their own settings, filters etc. All off these exist because there is no ‘perfect way’ of upsampling.

Puristic audiophiles who don’t like upsampling tend to turn this completely off and want the source to be transported to the DAC unaltered (bit perfect). Others like to upsample and tinker with the different settings. There is no ‘better or worse’ here. It all boils down to taste and preference.

Suffice to say that a lot of people enjoy to use ‘audiophile’ software (like Audirvana, HQPlayer, Roon, Foobar, etc. etc.) because of these possibilities.

Upsampling: in computer or in DAC ??? - General Forum - Audiophile Style

Getting something for nothing – PS Audio

Software Upsampling vs. DAC upsampling | Headphone Reviews and Discussion -


Andy Thanks for this input. Yes I kind of guessed that it would all boil down to personal taste and I suppose it also depends on the quality of users hifi separates and whether they feel their sound needs some tweaking. Cheers for posting the links.

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Perhaps there are no standard setting as every ear and every hifi equipment is different. But nevertheless: factory setting should be restorable as a software option; at least they should be document in the help files.

As I do not find them and mine are slightly different from @RunHomeSlow, I am asking: Which setting is the actual “factory setting” of Audirvana Studio 1.12 for SoX ?
Is it that @RunHomeSlow published Upsampling Filter Settings - #2 by RunHomeSlow or is it the following I found:

I have never changed the SoX parameters in Audirvana 3.5:

So the settings above should be the default settings in 3.5.

In Audirvana Studio 1.12.2 I use r8Brain and never changed the parameters to SoX also.
So the default settings there are (not surprisingly the same as in 3.5):

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Thank you @AndyLubke. That is the same as I found, except for Filter Phase.

:notes: :eye: :headphones: :eye: :notes:… This article will provide more insight into the concept of "Interpolation’ (specifically section 3.3 “Implementation”):

:notes: :eye: :headphones: :eye: :notes:… This quote from the NativeDSD help article written by Brian Moura, Playing DSD, DXD and Very High Bit Rate PCM files | NativeDSD Help will help make the distinction between PCMxxx “Interpolation” and PCM “Remodulation” to DSDxxx:

Differences between DSD and PCM

There’s no relationship between any DSD bit rate, and any PCM sample rate. Any DSD bit rate can be converted (remodulated) to any PCM sample rate, and vice versa. DXD (352.8 kHz) and Very High Bit Rate PCM (384 kHz) are the highest professional PCM rates employed today. DXD started as an editing format developed by Philips and Merging Technologies.

DSD and PCM are completely different digital encoding standards.

PCM is a series of completely independent binary coded samples representing actual numerical arithmetic values of signal level at the time of the sample.

DSD is a modulated bit stream comprised of a population of (clock) bits whose density is proportional to signal level, and unlike PCM, DSD contains no numerical values. Recording in DSD 256 does not imply any PCM derivative of any sample rate.

  • With PCM, think of movie film made of individual stand alone frames, each containing a separate picture (or signal value) in a sequence of separate pictures.
  • With DSD, think of a picket fence with more or less pickets present, proportional to the original signal level.

The word “Upsampling” applies only to PCM to (another form of) PCM, which contains samples to be rate multiplied. Converting any DSD rate to another DSD bit rate involves remodulation, not simple multiplication and interpolation as with PCM to PCM.

:notes: :eye: :headphones: :eye: :notes:…This article will provide insight into the differences between PCM and DSD signals:

Thank you for the reading tips @Agoldnear. So I know what to do this evening. I am just seeking a better understanding. Neither my equipment nor my ears most probably allow to hear any differences.

Ears are a factor by the way that is often neglected in reviews or tests!

:notes: :eye: :headphones: :eye: :notes:… You will find some insights into hearing acuity and auditory perception in this discussion:

Thank you for your additional reading links @Agoldnear.

Try with:

DoP 1.0
uncheck "large buffer’
normal polarity
r8brain power of two 91.5/116/linear

These are my (best) subjective settings used at the moment. I can not guarantee you will think the same - most probabily not.