Nice Review of DSD by Andreas Koch

[MylesBAstor]

That is correct. They both have their strengths/weaknesses and you need to use them accordingly.

Kinda like working out There's no perfect exercise: only the right exercise for the right person at the right time

 

[Ron Party]

That's a great line! I'm gonna try to remember that one.

 

[amirm]

So to summarize, you prefer the sound of DSD, but the measurements show it's flawed.

Well, it depends on one's definition of flawed. In 20 to 20 Khz, both of them "measure" perfectly. Andreas paper seems to argue for having better than 144 db dynamic range of PCM. Surely that is not a target, is it? If it is, the analog is the first one thrown off the boat .

The argument then turns into the odd bit of what is above our normal hearing range that needs to be preserved and how. It is in that area that DSD is highly distorted relative to PCM (but then extends past it) that has flat response above our hearing range.

So maybe we're not measuring the right thing or as Andreas suggests, there's some psychoacoustics at work.

I don't think it is an issue of measurement but quantifying what it is about ultransonics that is good, if anything. Maybe there is nothing there and it is all about filters. Or there is something there.

Sorry but I don't see this as marketing material but a basic introduction for the average audiophile on what DSD/SACD is about.

I call a basic introduction of this type, marketing material . If it included the points I made which he is well aware of, then it would have been a proper introduction. He also makes points that are not substantiated such as the 100 Khz bit with language:

"The slowly rising noise floor at higher frequencies also follows to some degree our hearing threshold for transient signals that have been proven to be audible up to 100kHz."

When someone says stuff like this but provides no reference whatsoever or explanation as to why, then it is a claim and that is what marketing material is.

BTW, Andreas Is probably one of the foremost experts on subject of DSD (he was also with Meitner---and Ed was a consultant to Sony) and his PD is the best digital playback system I've heard to date. Might I add Andreas has implemented some unique things in his digital gear.

I am debating what he has written, not who he is. That said, knowing his background, I am on guard that he is trying to defend/sell his baby. In that regard, he needs to go out of his way to look neutral. My read of the paper was the opposite in that it covered the basic talking points of DSD with a few additional tidbits like the above quote thrown around.

A fair appraisal would start with knowing that we can't hear above 20 Khz, and we don't know why preserving stuff above 20 Khz is important, that listening tests routinely show there is no value to preserving higher frequency content, etc. In other words, the proposal for DSD is a contrarian one. You don't get to start assuming it is all needed and then say this is a best method *from a technical* point of view.

Now if one is writing a marketing brochure, then sure, we can claim anything as a) needed and b) the best way to do it. That is what he has written.

I guess I am more sensitive to things that look technical and hence authoritative, than stuff that is clearly not technical. The former can do damage due to appearance of it looking official and therefore right.

 

[microstrip]

That is correct. They both have their strengths/weaknesses and you need to use them accordingly.

Bruce,
Can we consider that for digitizing existing analogue material, that has foreseen maximum levels and dynamic range, DSD using an unit such as the Korg would be better than PCM 24/96?

 

[microstrip]

Well, it depends on one's definition of flawed. In 20 to 20 Khz, both of them "measure" perfectly. Andreas paper seems to argue for having better than 144 db dynamic range of PCM. Surely that is not a target, is it? If it is, the analog is the first one thrown off the boat .

The argument then turns into the odd bit of what is above our normal hearing range that needs to be preserved and how. It is in that area that DSD is highly distorted relative to PCM (but then extends past it) that has flat response above our hearing range.

Amir,

As far as could read in the PF article, the only interesting reason that is referred to prefer DSD is the absence of the steep brickwalls that PCM signals typically have. It is those brickwalls that can generate very audible side-effects (quoting PF). Even PCM at 192 kHZ has ultra-sonic capabilities beyond what we are debating.

How do current state of the art PCM systems handle these steep brickwalls?

 

[amirm]

How do current state of the art PCM systems handle these steep brickwalls?

One method to resample to a higher rate but then filter gently since we don't need to be flat in ultrasonic frequencies. Here is an example in my quick search:

The graphs to the right are the 96 Khz ones, the one to the left are 44.1. With the latter, we are so close to the audio pass band that very sharp filters are used. Whereas with the 96 Khz, we can take 30 Khz to get down to nothing.

 

[amirm]

Adding on, if we deliver at higher PCM resolutions, then we don't need to resample either yet take advantage of gentle roll off which can be user selectable.

 

[Bruce B]

Bruce,
Can we consider that for digitizing existing analogue material, that has foreseen maximum levels and dynamic range, DSD using an unit such as the Korg would be better than PCM 24/96?

i have always stated that the Korg MR2000s is the best 2-channel recorder under $10k. It's an amazing machine for the price of $1500.
And to get better fidelity and keep the nay-sayers quiet, record at DSD128fs.

 

[NorthStar]

That is correct. They both have their strengths/weaknesses and you need to use them accordingly.

What I found very interesting Bruce, according to your own experiments,
is that Volume level is also directly related, and also the type of recorded Music.

* Are some speakers better sounding at a certain volume level for a certain room size,
and/or the Music genre, and also the recording medium (& technics), and also mic(s) used,
are part of this totality, or separate entities with unique variances?

** Is audio information in the 50 to 200 kHz frequency range important
for affecting the audio frequencies of the normal listening human range (20 Hz to 20 kHz)?
- Or let's say the 22 kHz to 122 kHz information; to stay more down where we live. :b

 

[microstrip]

i have always stated that the Korg MR2000s is the best 2-channel recorder under $10k. It's an amazing machine for the price of $1500.
And to get better fidelity and keep the nay-sayers quiet, record at DSD128fs.

Thanks! What do you think about the MR2000 analogue output converters quality? I was just discussing with a friend the possibility of making some DSD 128fs recordings from the analogue output of one the best CD playing systems and compare it with a medium price CD player playing the same CD.

 

[Bruce B]

Thanks! What do you think about the MR2000 analogue output converters quality? I was just discussing with a friend the possibility of making some DSD 128fs recordings from the analogue output of one the best CD playing systems and compare it with a medium price CD player playing the same CD.

The best DSD DAC I have heard under $10k is the Playback Designs MPD-3, which will allow you to play DSD128fs files. The Korg's DAC is not up to the level of the Playback Designs but from what I've heard, it's on par with the Mytek DSD converter. Unfortunately the Mytek will not accept DSD128fs..... yet.

 

[Bruce B]

* Are some speakers better sounding at a certain volume level for a certain room size,
and/or the Music genre, and also the recording medium (& technics), and also mic(s) used,
are part of this totality, or separate entities with unique variances?

** Is audio information in the 50 to 200 kHz frequency range important
for affecting the audio frequencies of the normal listening human range (20 Hz to 20 kHz)?
- Or let's say the 22 kHz to 122 kHz information; to stay more down where we live. :b

Yes, there are speakers that excel at certain genres of music. I love planer speakers on acoustical music. I haven't heard a dynamic speaker that can touch a planer in the mids.

The Fletcher/Munson curve shows that human hearing is more susceptible to freq. in the 250 - 5k range. If the freq. at 50 - 200Hz isn't right, it can leave the 250 - 5k range very muddy/dark. I'd say 70% of the material that comes through here has issues in the 50 - 200Hz range. Think about the trend in the past 5yr. where more engineers are cutting cost and recording/mixing in less than optimal rooms. The room issues show up in the files we get. Most of the room issues are exacerbated when engineers are sitting in nulls between 50-75Hz.... and then you get the harmonic of 100-150Hz as well..

 

[mep]

I’m a little confused. If you download DSD files to your computer, can you play them back through the Korg or do you have to have another D/A converter?

 

[Bruce B]

I’m a little confused. If you download DSD files to your computer, can you play them back through the Korg or do you have to have another D/A converter?

You connect the Korg unit to your computer via USB and it shows up as an external drive. Transfer the DSD files you downloaded onto the Korg's own hard drive and hit play.

There has been some success in replacing the 80GB drive with a 320GB drive for a larger playlist.

 

[NorthStar]

Yes, there are speakers that excel at certain genres of music. I love planer speakers on acoustical music. I haven't heard a dynamic speaker that can touch a planer in the mids.

The Fletcher/Munson curve shows that human hearing is more susceptible to freq. in the 250 - 5k range. If the freq. at 50 - 200Hz isn't right, it can leave the 250 - 5k range very muddy/dark. I'd say 70% of the material that comes through here has issues in the 50 - 200Hz range. Think about the trend in the past 5yr. where more engineers are cutting cost and recording/mixing in less than optimal rooms. The room issues show up in the files we get. Most of the room issues are exacerbated when engineers are sitting in nulls between 50-75Hz.... and then you get the harmonic of 100-150Hz as well..

Wow!

First thank you for your reply.
And what you just said above, I am in total agreement with you!

Everything is important; even what you don't see and hear.
Plus each piece has its own range of qualitative specificity;
like a certain type of loudspeaker excelling at the reproduction of some particular instruments in the music.

The ultrasonic frequencies (way beyond the human range) have a direct influence on what we perceive in our own capabilities (human audio range). And same with the extreme lower sub frequencies (0.01 Hz to 10 Hz).
That's what I believe.

* We need more advanced and better mics! :b ...And recording machines as well, of course.
...DSD, LPCM or not.

 

[fas42]

Curious, Bruce, have you tried brick wall filtering in a DAW of a top notch digital recording which has genuine above 20kHz content, ie., not just noise; to then have the original and a version 100% stripped of "ultrasonic" frequencies content compared on the best playback setup for monitoring such -- could you hear a difference?

Frank

 

[Bruce B]

Curious, Bruce, have you tried brick wall filtering in a DAW of a top notch digital recording which has genuine above 20kHz content, ie., not just noise; to then have the original and a version 100% stripped of "ultrasonic" frequencies content compared on the best playback setup for monitoring such -- could you hear a difference?
Frank

Helen Keller could hear a difference!
Case in point... The FIM recording of the Yamamoto Trio that I did in both DSD and DXD was ultimately released on CD. Though as good as the CD sounded, it paled in comparison to the original files. We tried all kinds of Linear phase, Minimal phase and Apodizing filters and 4-5 dither algorithms to bring the files down to 16/44.1 , but nothing was as good as the original.

 

[fas42]

Helen Keller could hear a difference!
Case in point... The FIM recording of the Yamamoto Trio that I did in both DSD and DXD was ultimately released on CD. Though as good as the CD sounded, it paled in comparison to the original files. We tried all kinds of Linear phase, Minimal phase and Apodizing filters and 4-5 dither algorithms to bring the files down to 16/44.1 , but nothing was as good as the original.

Sorry, Bruce, you didn't get my drift. I meant that both the original and filtered version were on exactly equivalent DSD formats and media: they are "identical" files, except that the spectrum for the filtered version will show no content above 20kHz.

Frank

 

[Bruce B]

Sorry, Bruce, you didn't get my drift. I meant that both the original and filtered version were on exactly equivalent DSD formats and media: they are "identical" files, except that that spectrum for the filtered version will show no content above 20kHz.
Frank

Sorry Frank... we've used some pretty steep filters to block out some of the UHF, but the only way we can brickwall something is to do an actual conversion to a lower sample rate and then back to DSD. Then you will still have dither/noise shaping above 20k
The ones we did that used steep filters took the life right out of the music. A gentler slope like the ones I use when doing files for HDtracks, still retains most of the life and emition that's in there.

 

[microstrip]

Bruce,
Another tricky question - suppose you digitize analog sources using DSD 128fx , convert to 24 bit 192kHz (the highest PCM resolution we can get in standard consumer DACs) using a software utility and play it at this resolution using a top PCM DAC. Do you get a better result than digitizing directly to PCM 24/192?