Doesn't the Roon app allow eq and other DSP to be applied to DSD without changing to PSM? If so, why can’t Sony implement this feature?
Last edited:
SONY NW-ZX500
Doesn't the Roon app allow eq and other DSP to be applied to DSD without changing to PSM? If so, why can’t Sony implement this feature?
- Joined
- Oct 14, 2013
- Posts
- 28,361
- Likes
- 32,235
I do not know about Roon as I do not use it, but it is “Facts”. You Can Not Process DSD in it Native form Unless it is “None Native”
Nothing can change that
Idk dude. Check this out. Here’s an explanation from a tech from Roon that was quoted on Audiophilestyle.com:
I asked at the Roon Community what Roon actually does when EQ is applied to DSD, as the Roon Signal path doesn't indicate conversion to PCM. This is the (somewhat surprising) answer.
We do indeed process DSD without performing a DSD->PCM conversion first. The signal path is reflecting that accurately.
I’m going to explain how it works–keep in mind that there are some subtle technical details here, and some background knowledge is required to understand them fully. Processing DSD isn’t nearly as straightforward as processing PCM. With the exception of a few simple operations, you can’t process it directly in the 1-bit representation. There are more steps involved, but it’s possible to perform those steps in a way that keeps all of the important properties of DSD intact.
First, I’ll explain DSD->PCM conversion, because it helps to understand the other technique in a relative sense.
DSD->PCM conversion starts with a with a DSD signal and produces a signal with two characteristics:
PCM representation (lower sample rate, wider samples)
Low noise floor throughout the frequency domain of the PCM format that is as flat as possible.
The first one is obvious–we need a PCM-like representation at the end. The second goal is more subtle–it is saying that the content of the signal must look like a PCM signal. It must be accepted and played properly by PCM equipment. It must be processable by downstream DSP processes that expect to work with PCM data, and so on. It must not cause damage to equipment that’s expecting PCM.
This is accomplished in three steps:
Start with a DSD stream, and widen from 1 bit-per-sample to 64 bits-per-sample
Downsample it by 8x (so DSD64 -> 352.8kHz, DSD128 -> 705.6kHz, etc).
Apply a low pass “reconstruction filter”. This filter also exists in a DSD DAC, but since we are effectively simulating the DAC, we must simulate that aspect here too, since PCM DACs do not have this filter.
The reconstruction filter removes the noise inherent to the DSD signal before it can reach equipment that might not be prepared to handle it. Most of the energy in a DSD signal lives in this noise (well over 95%), so even though the noise is all at inaudible high frequencies, it’s important to filter it out so that your gear is not asked to turn that energy into loud, high frequency sound.
If you look at a spectrogram of DSD->PCM converted data, it looks like a PCM signal. Depending on the source material, and the sensitivity of your spectrogram, you might see a bit of a very quiet noise floor in the area where the transition band of the noise shaping filter used during mastering crosses over with the transition band of the DSD->PCM low pass filter (30-60kHz for DSD64).
OK, so now that DSD->PCM is explained, lets talk about the case you’re actually interested in–the one where we process and output DSD without converting it to PCM.
This works like this:
Start with a DSD stream, and widen from 1 bit-per-sample to 64 bits-per-sample
Apply a low pass filter to remove the bulk of the inherent noise energy from the widened signal.
Apply processing steps to the wide intermediate format.
Send the signal through a sigma-delta-modulator to re-render the “wide” 64-bit stream into a 1-bit DSD stream.
The low pass filter (2) in this process might sound like the reconstruction filter we discussed above, but it is very different. It is much more lenient, less steep, and it only attenuates frequencies over 100kHz–and these already have a very poor SNR because of the inherent noise shaping in DSD, so we can be sure that no meaningful information existed there in the first place.
Without the filter, sound quality suffers significantly or the sigma delta modulator risks becoming unstable (i.e. starts outputting horrible sounds that ruin your ears and if you’re unlucky your gear too).
At step (3) the signal is structurally similar to a PCM signal–in that it is comprised of a series of multi-bit samples. However, it does not have content typical of PCM signals and it maintains the DSD sample rate. If you looked at a spectrogram of the intermediate format in (3), it would look just like DSD, except with the bulk of the noise above 100kHz severely attenuated by the low pass filter.
By maintaining the original sample rate through processing, the time-domain characteristics of DSD are maintained. By designing the filter to stay far away from musical content, the frequency-domain characteristics are maintained too.
Sometimes this form of processing, or this intermediate format is referred to as “DSD-Wide”. We didn’t use that term because some people have defined DSD-Wide as an 8 bit intermediate format (whereas we use 64 bits…a luxury of precision afforded to us by running on modern desktop-class CPUs) and I didn’t want to create confusion.
I asked at the Roon Community what Roon actually does when EQ is applied to DSD, as the Roon Signal path doesn't indicate conversion to PCM. This is the (somewhat surprising) answer.
We do indeed process DSD without performing a DSD->PCM conversion first. The signal path is reflecting that accurately.
I’m going to explain how it works–keep in mind that there are some subtle technical details here, and some background knowledge is required to understand them fully. Processing DSD isn’t nearly as straightforward as processing PCM. With the exception of a few simple operations, you can’t process it directly in the 1-bit representation. There are more steps involved, but it’s possible to perform those steps in a way that keeps all of the important properties of DSD intact.
First, I’ll explain DSD->PCM conversion, because it helps to understand the other technique in a relative sense.
DSD->PCM conversion starts with a with a DSD signal and produces a signal with two characteristics:
PCM representation (lower sample rate, wider samples)
Low noise floor throughout the frequency domain of the PCM format that is as flat as possible.
The first one is obvious–we need a PCM-like representation at the end. The second goal is more subtle–it is saying that the content of the signal must look like a PCM signal. It must be accepted and played properly by PCM equipment. It must be processable by downstream DSP processes that expect to work with PCM data, and so on. It must not cause damage to equipment that’s expecting PCM.
This is accomplished in three steps:
Start with a DSD stream, and widen from 1 bit-per-sample to 64 bits-per-sample
Downsample it by 8x (so DSD64 -> 352.8kHz, DSD128 -> 705.6kHz, etc).
Apply a low pass “reconstruction filter”. This filter also exists in a DSD DAC, but since we are effectively simulating the DAC, we must simulate that aspect here too, since PCM DACs do not have this filter.
The reconstruction filter removes the noise inherent to the DSD signal before it can reach equipment that might not be prepared to handle it. Most of the energy in a DSD signal lives in this noise (well over 95%), so even though the noise is all at inaudible high frequencies, it’s important to filter it out so that your gear is not asked to turn that energy into loud, high frequency sound.
If you look at a spectrogram of DSD->PCM converted data, it looks like a PCM signal. Depending on the source material, and the sensitivity of your spectrogram, you might see a bit of a very quiet noise floor in the area where the transition band of the noise shaping filter used during mastering crosses over with the transition band of the DSD->PCM low pass filter (30-60kHz for DSD64).
OK, so now that DSD->PCM is explained, lets talk about the case you’re actually interested in–the one where we process and output DSD without converting it to PCM.
This works like this:
Start with a DSD stream, and widen from 1 bit-per-sample to 64 bits-per-sample
Apply a low pass filter to remove the bulk of the inherent noise energy from the widened signal.
Apply processing steps to the wide intermediate format.
Send the signal through a sigma-delta-modulator to re-render the “wide” 64-bit stream into a 1-bit DSD stream.
The low pass filter (2) in this process might sound like the reconstruction filter we discussed above, but it is very different. It is much more lenient, less steep, and it only attenuates frequencies over 100kHz–and these already have a very poor SNR because of the inherent noise shaping in DSD, so we can be sure that no meaningful information existed there in the first place.
Without the filter, sound quality suffers significantly or the sigma delta modulator risks becoming unstable (i.e. starts outputting horrible sounds that ruin your ears and if you’re unlucky your gear too).
At step (3) the signal is structurally similar to a PCM signal–in that it is comprised of a series of multi-bit samples. However, it does not have content typical of PCM signals and it maintains the DSD sample rate. If you looked at a spectrogram of the intermediate format in (3), it would look just like DSD, except with the bulk of the noise above 100kHz severely attenuated by the low pass filter.
By maintaining the original sample rate through processing, the time-domain characteristics of DSD are maintained. By designing the filter to stay far away from musical content, the frequency-domain characteristics are maintained too.
Sometimes this form of processing, or this intermediate format is referred to as “DSD-Wide”. We didn’t use that term because some people have defined DSD-Wide as an 8 bit intermediate format (whereas we use 64 bits…a luxury of precision afforded to us by running on modern desktop-class CPUs) and I didn’t want to create confusion.
inexactscience
Head-Fier
No info on the site indicates this. Apparently I deleted everything after "no". Whoops.
Last edited:
Read what I posted above. It’s from Roon’s then Chief Technical Officer, Brian Luczkiewicz. It explains the process of applying DSP to DSD without converting to PCM.
inexactscience
Head-Fier
I just finished the first read through of your post and it doesn't make 100% sense to me, because it seems like the dude is contradicting himself. I may also just not be fully comprehending the full content, so take that with a grain of salt.
I did find more information on Roon's site to explain what they do with DSD, some of which is listed here: https://kb.roonlabs.com/Conversion_To_PCM and I had to more or less navigate my way there. The indications I get from that article are that 1: Roon converts DSD to PCM for all DSP. 2. Roon can integrate with an application, HQPlayer, to apply DSD signal processing without PCM or DXD conversion.
Integrating that information with the explanation from Roon's CTO, it looks like Roon converts DSD to a form of PCM (which is what I'm interpreting that "bit-widening" and filtering as), but doesn't downsample and applies a different (lowpass, not reconstruction) filter before they then apply the DSP, and reconvert back to DSD. HQPlayer may have a different method, of which I am ignorant at this time.
What's notable is that both HQPlayer and Roon require a desktop class CPU or GPU in order to apply any DSP to DSD without the conversion to PCM.
Which means that Sony won't be able to process DSP on DSD with their underpowered mobile processor.
jay1982
New Head-Fier
- Joined
- Jan 13, 2017
- Posts
- 34
- Likes
- 22
Hello
I’m sorry to keep asking questions but I am new to all this audio Walkman stuff. As you know I have purchased the zx500 and I want to use the balance input. I have the new WI 1000xm2 which does not have 4.4 connector but i saw this and purchased.
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/232924061380
I have tried it and it works, only one thing I’m not sure about. It plays well but when I change songs it makes a clicking noise for a split second. Do you know if this is normal, i don’t want to use it and then it damages the Walkman. I have the MDR Z7M2 which does have the 4.4 connector and doesn’t make this noise.
I’m sorry to keep asking questions but I am new to all this audio Walkman stuff. As you know I have purchased the zx500 and I want to use the balance input. I have the new WI 1000xm2 which does not have 4.4 connector but i saw this and purchased.
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/232924061380
I have tried it and it works, only one thing I’m not sure about. It plays well but when I change songs it makes a clicking noise for a split second. Do you know if this is normal, i don’t want to use it and then it damages the Walkman. I have the MDR Z7M2 which does have the 4.4 connector and doesn’t make this noise.
- Joined
- Oct 14, 2013
- Posts
- 28,361
- Likes
- 32,235
That is just another fancy ways of saying we are DSP processing the DSD by converting it into quantization step into 64 bits...blah blah blah...reverse the delta sigma blah blah....
That my friend, is PCM
if you want to understand more about this, you can read into HQplayer, Chord, and other digital processing technique
Basically, applying Delta Sigma to PCM will turn it to DSD
So, DSD with reversing Sigma-Delta is PCM
no need to Fancy words salad and make it confusing
That my friend, is PCM
if you want to understand more about this, you can read into HQplayer, Chord, and other digital processing technique
Basically, applying Delta Sigma to PCM will turn it to DSD
So, DSD with reversing Sigma-Delta is PCM
no need to Fancy words salad and make it confusing
Last edited:
I’m not totally convinced, but ok.
Lol we believe what we want to believe at the end of the day i guess.
inexactscience
Head-Fier
@Whitigir
That was my interpretation, it's just yours is a bit more concise. I feel a bit better that I understood at least some of that "words salad" as you put it.
The good news is you don't have to take my word for it. Read the Roon link I supplied (or find it yourself), parse out Roon CTO's statement, and read up on the DSD wikipedia article (here: https://en.wikipedia.org/wiki/Direct_Stream_Digital) under the "DSD Technique" heading.
Do that, and I don't think there's any different conclusion anyone can reasonably come to. Though, if someone does, I'd love to hear the reasoning.
That was my interpretation, it's just yours is a bit more concise. I feel a bit better that I understood at least some of that "words salad" as you put it.
The good news is you don't have to take my word for it. Read the Roon link I supplied (or find it yourself), parse out Roon CTO's statement, and read up on the DSD wikipedia article (here: https://en.wikipedia.org/wiki/Direct_Stream_Digital) under the "DSD Technique" heading.
Do that, and I don't think there's any different conclusion anyone can reasonably come to. Though, if someone does, I'd love to hear the reasoning.
I suppose. So no chance Sony came up w something awesome that changes the game a bit w regard to DSD? Ok. Still pretty good that it can toggle to some form of PCM so fast while still sounding like a DSD file w DSP applied.
inexactscience
Head-Fier
That's what matters!
This hobby is all about experience. We can talk about the science all we want, but at the end of the day, if you (or I, or anyone, really) enjoys what you're listening to, then that's the experience that matters.
I'm in this specific forum because I'm trying to learn if this ZX500 is going to provide me with the experience I desire: portable music (streaming & local) and audiobooks (streaming & local) while I'm at work or on the go. If I get an enjoyable experience listening to DSD converted to PCM music, then does it really matter that it's not native DSD? If I can't personally tell the difference between DSD256, fully decoded MQA, a 16-bit, 44.1kHz Tidal stream, and a 320kbps Spotify track, then really, should I worry which format I use?
Naturally, I'm still waiting for someone to give a solid answer to @rantng about the firmware on the ZX505 (from this post) because that's a nice option to have, if one can get Google Play support on that model.
- Joined
- Oct 14, 2013
- Posts
- 28,361
- Likes
- 32,235
yepe! Trust your ears is all this hobby is about. Don’t even be swayed by what others are saying. We are all uniquely different from one another. Just so long as you are enjoying the same hobby as I do, that is what matters
comrades!
wanna hear a joke?
Kyiv, Ukraine zx507 is sold for $1150. (probably with EU volume cap / no high gain)
zx507 price is $670 in Japan
https://hires.com.ua/muzykalnyi-pleer-sony-walkman-nw-zx507-chernyi/p8385/
wanna hear a joke?
Kyiv, Ukraine zx507 is sold for $1150. (probably with EU volume cap / no high gain)
zx507 price is $670 in Japan
https://hires.com.ua/muzykalnyi-pleer-sony-walkman-nw-zx507-chernyi/p8385/
You can use Lux Dashboard to reduce screen brightness more than what the device allows by default.
Users who are viewing this thread
