How can DAC's have a SOUND SIGNATURE if they measure as transparent?

[Newman]

have you heard of the mystery of the vinyl renaissance?

Haha that's hilarious. The more the truth talkers try to clear it up with demonstrable truths, the more the obfuscators pour smoke into the space with Russell's Teapots. Without determined pro-science moderation, it will only end with a hollow Victory of the Last Word. The opposite of what ASR is here for, IMO.

I suppose this thread is doomed to the same fate.

 

[Jimbob54]

Haha that's hilarious. The more the truth talkers try to clear it up with demonstrable truths, the more the obfuscators pour smoke into the space with Russell's Teapots. Without determined pro-science moderation, it will only end with a hollow Victory of the Last Word. The opposite of what ASR is here for, IMO.

I suppose this thread is doomed to the same fate.

If you keep making these tribalistic comments then yes.

Let's not do the vinyl thread here too please

 

[Newman]

Supporting science in the face of denial isn't tribalism, it's core business.

Happy to not do the vinyl thread anywhere, but recognising patterns of behaviour increases understanding. So does organising points of view into categories for the purpose of addressing them as a whole.

Forcing each comment to be addressed individually when they are repetitive creates a 10,000 post thread when 100 might have done it.

Cheers

 

[TLEDDY]

Did they really use the word base instead of bass?

Why I hate Spell-check!

Tillman

 

[TLEDDY]

Almost always such devices are outperformed by budget offerings. The Fosi portable Amp/DACtested yesterday which costs $68 USD is, for all intents and purposes, perfect. If a $100k DAC is producing something audibly different, it's producing something worse.

I think your moniker is absolutely wonderful!!

Tillman

 

[flipflop]

An objectivist psychoacoustician PhD AES scientist professor and measurement taker was teaching a class on Harvey Fletcher, a known physicist.

"Before the class begins, you must acknowledge that human hearing is easily fooled and that measurements are highly resolving, even more so than our ears!"

At this moment, an unbiased, experienced, golden-eared subjectivist audio reviewer guru who had performed 1500 hours of burn-in and understood the necessity of cable risers and had fully covered his listening room with acoustic panels stood up and held up a DAC.

"What's the sound signature of this DAC?"

The arrogant professor smirked quite objectively and scientifically replied "DACs don't have a sound signature, you snake oil peddler"

"Wrong. It has a grainy treble and no microdetails. If it was high fidelity and measurements, as you say, are everything... then it should have a chocolaty PRaT"

The professor was visibly shaken, and dropped his APx555 and copy of Sound Reproduction. He stormed out of the semi-reflective room crying those objectivist crocodile tears. The same tears objectivists cry when you refuse to take a blind test of a night and day difference (that can even be heard by your wife from the kitchen). There is no doubt that at this point our professor, bankrolled by the NRC, wished he had learned to listen critically and become more than a close-minded objectivist professor. He wished so much that he had a silver cable to hang himself from embarrassment, but he himself had advocated against them!

The students applauded and all purchased turntables that day and rejected inferior formats with digital glare. A tutorial named "The Ultimate Guide to Tube Rolling" was circulated among the students and on internet forums and at audio conventions. Audio magazine prose was read extensively, and acoustic treatment salesmen showed up and killed the room reflections.

The professor lost his hearing and was fired the next day. He died from getting shocked by a headphone amplifier without proper safety grounding and was ridiculed by audiophiles for all eternity.

Trust Your Ears

 

[Mort]

Random but I'll allow it.

 

[Muddywaters]

What’s the date?

 

[Blockader]

An objectivist psychoacoustician PhD AES scientist professor and measurement taker was teaching a class on Harvey Fletcher, a known physicist.

"Before the class begins, you must acknowledge that human hearing is easily fooled and that measurements are highly resolving, even more so than our ears!"

At this moment, an unbiased, experienced, golden-eared subjectivist audio reviewer guru who had performed 1500 hours of burn-in and understood the necessity of cable risers and had fully covered his listening room with acoustic panels stood up and held up a DAC.

"What's the sound signature of this DAC?"

The arrogant professor smirked quite objectively and scientifically replied "DACs don't have a sound signature, you snake oil peddler"

"Wrong. It has a grainy treble and no microdetails. If it was high fidelity and measurements, as you say, are everything... then it should have a chocolaty PRaT"

The professor was visibly shaken, and dropped his APx555 and copy of Sound Reproduction. He stormed out of the semi-reflective room crying those objectivist crocodile tears. The same tears objectivists cry when you refuse to take a blind test of a night and day difference (that can even be heard by your wife from the kitchen). There is no doubt that at this point our professor, bankrolled by the NRC, wished he had learned to listen critically and become more than a close-minded objectivist professor. He wished so much that he had a silver cable to hang himself from embarrassment, but he himself had advocated against them!

The students applauded and all purchased turntables that day and rejected inferior formats with digital glare. A tutorial named "The Ultimate Guide to Tube Rolling" was circulated among the students and on internet forums and at audio conventions. Audio magazine prose was read extensively, and acoustic treatment salesmen showed up and killed the room reflections.

The professor lost his hearing and was fired the next day. He died from getting shocked by a headphone amplifier without proper safety grounding and was ridiculed by audiophiles for all eternity.

Trust Your Ears

The professor was on Topping's marketing payroll, which explains his obsession with measurements and SINAD. Good riddance. /s

 

[BDWoody]

Trust Your Ears

Uh huh.

Moved to this thread as part of the April 1st celebration.

 

[donjoe0]

To pick up where I left off with the comparison of the FiiO KA17 and the Hiby FC3 (or the investigation of the KA17's failings that make it sound veiled/warmer), I will note that I heard the difference between them a few times again while playing through headphones (HE-400i) but haven't gone through the pains of setting up a proper ABX test at a quiet time of day and in good biopsychological condition.

Meanwhile I thought to do more measurements-based comparisons to try to get more data on what tends to be different between these dongles' output and maybe get a better sense of how I should choose the right material to ABX.

Since I didn't have much success measuring device FRs with the Multitone tool, I thought to switch things up and put white noise through each device and loop it back in repeatedly, to show any defects better amplified and easier to spot. Easier to do with just Audacity and a music player. So for the Hiby FC3 what I got was what I already knew:
* it has no warm tilt, average magnitude response is flat all across the audio band
* in-band ripples are present but they're unlikely to be audible based on known research: 0.05 dB peak-to-peak on the FR curve (about 0.2 dB after 4 loopback passes as shown in the image) - though I wouldn't mind seeing this tested in listening comparisons by "golden ears" vs. some other DACs with even flatter filter response

OK, KA17, it's your time to shine:

* visible veiled tilt, mostly beyond 7.5k, overall about 0.2 dB from 0 Hz to 18 kHz in 4 passes, so about 0.05 dB when listening to music
Could this by itself be all the difference that I heard? It's true it only came out in some parts of some songs but still...

But wait, what's this? Why does the oscillogram look like that? That's not what I expect when looking at a white noise track, and it's not what the FC3 recordings looked like even after 4 passes:

Did it take that shape over time? What does the 1st pass look like?

6-second period infrasonics? WTF?

What if I put just a 1 kHz tone through and look at the FR?

Subharmonic distortion lobes of some kind, going up beyond -60 dB. Unfortunately Audacity doesn't allow frequency zoom - that I know of - so I can't tell if the 0.167 Hz infrasonic component was produced directly or is some beat frequency between those other lobes.

Now bass distortion is the least audible of all, and this could just be the underlying mechanism that leads to that overall very mild warm tilt, but still... no well-behaved DAC should do this. What if it causes weird interactions with other frequencies depending on the song (and song section!) being played, resulting in audible artifacts beyond just a vague tilt? Could we see something if we put a song through and DeltaWave it vs. the original file?

OK, same vaguely warm tilt going into the treble, before the noise let through by the filter starts to dominate... but also massive sub-bass spikes. Like, even if these aren't audible because my headphones can't produce them at the right volume, I'd bet they can affect how the rest of the frequencies are presented, by periodically pushing the membrane too close to xmax.

Also, the delta of spectra in spectrogram form gives another hint: the KA17's problems seem to come out more in the simpler sections of the song with the more sparse spectra (wherever you're seeing the thicker red lines in the sub-bass and extra energy shades going up across the whole band is where most instruments and voices went quiet).

Was this a one-off? What if I re-record the same song today?

Nope, pretty much the same. Weird sub-bass spikes galore. (Notice the fit quality doesn't make a difference, since we're not analyzing the time-domain delta, only the spectral delta.)

So going forward what this leaves me with is I should try more songs, and especially focus on more minimalistic ones - less symphonic, less white-noise-like - and check their spectra in DeltaWave, to find the best section of the best song to put in my ABX test later.

But regardless of what result I will get there, I think these spectrograms already show the hypothesis that "all you need is a frequency sweep or white noise test" is far from correct: even at today's level of technology DAC/amps can respond quite differently depending on the material they're being fed, showing changes in tonality even within the same song.

 

[Count Dacula]

I guess we can say they measure differently

 

[solderdude]

Yes, all DACs measure differently, They can even measure differently when using the same DAC chip.
A DAC can even measure differently against itself when, for instance, a different reconstruction filter is selected.
There also can be run-to-run variations and sometimes even temperature can make a difference.
Just like the found SINAD value, for instance, can jump up and down a little and it depends on when one hits the 'save screen' button a little.

The real question is what is the audibility threshold when using music.
This (partly) depends on the chose recording (music), SPL level, transducers, hearing abilities, even time of day and physical/psychological well being and statistical relevance and even if the used music file has peaks reaching (very near) 0dBFS and above all ... training.
Then there is frequency response and how 'young' the hearing is.

 

[Count Dacula]

Yes, all DACs measure differently, They can even measure differently when using the same DAC chip.
A DAC can even measure differently against itself when, for instance, a different reconstruction filter is selected.
There also can be run-to-run variations and sometimes even temperature can make a difference.
Just like the found SINAD value, for instance, can jump up and down a little and it depends on when one hits the 'save screen' button a little.

The real question is what is the audibility threshold when using music.
This (partly) depends on the chose recording (music), SPL level, transducers, hearing abilities, even time of day and physical/psychological well being and statistical relevance and even if the used music file has peaks reaching (very near) 0dBFS and above all ... training.
Then there is frequency response and how 'young' the hearing is.

Also measurements change as the DAC ages out.

I understand the perception part. Wild guess is, these difference ARE audible....if they are isolated reproduced without the mask of noise and other music.
That is, play a sine wave with these levels of IMD or whatever, and I'm thinking yes... Play a tight recording of a Stratovarius, then distort it to the same degree....yes. Noise...how can you not hear noise???

 

[Count Dacula]

Some people think their old LP sounds great. Can they hear the difference between 86db and 91db SNR? Can we???

Pretty sure I can hear 8 bits vs 22 bits....but I'm pretty brash.

 

[danadam]

Pretty sure I can hear 8 bits vs 22 bits

In attachment 10 seconds excerpt from "Lady Gaga / Mayhem / 01. Disease" in 16 and 8 bits.

(I know, I know, it would be easily audible at the beginning of the song )

 

[Jimster480]

To pick up where I left off with the comparison of the FiiO KA17 and the Hiby FC3 (or the investigation of the KA17's failings that make it sound veiled/warmer), I will note that I heard the difference between them a few times again while playing through headphones (HE-400i) but haven't gone through the pains of setting up a proper ABX test at a quiet time of day and in good biopsychological condition.

Meanwhile I thought to do more measurements-based comparisons to try to get more data on what tends to be different between these dongles' output and maybe get a better sense of how I should choose the right material to ABX.

Since I didn't have much success measuring device FRs with the Multitone tool, I thought to switch things up and put white noise through each device and loop it back in repeatedly, to show any defects better amplified and easier to spot. Easier to do with just Audacity and a music player. So for the Hiby FC3 what I got was what I already knew:
* it has no warm tilt, average magnitude response is flat all across the audio band
* in-band ripples are present but they're unlikely to be audible based on known research: 0.05 dB peak-to-peak on the FR curve (about 0.2 dB after 4 loopback passes as shown in the image) - though I wouldn't mind seeing this tested in listening comparisons by "golden ears" vs. some other DACs with even flatter filter response
View attachment 441496

OK, KA17, it's your time to shine:
View attachment 441497
* visible veiled tilt, mostly beyond 7.5k, overall about 0.2 dB from 0 Hz to 18 kHz in 4 passes, so about 0.05 dB when listening to music
Could this by itself be all the difference that I heard? It's true it only came out in some parts of some songs but still...

But wait, what's this? Why does the oscillogram look like that? That's not what I expect when looking at a white noise track, and it's not what the FC3 recordings looked like even after 4 passes:
View attachment 441498

Did it take that shape over time? What does the 1st pass look like?
View attachment 441499
6-second period infrasonics? WTF?

What if I put just a 1 kHz tone through and look at the FR?
View attachment 441500
Subharmonic distortion lobes of some kind, going up beyond -60 dB. Unfortunately Audacity doesn't allow frequency zoom - that I know of - so I can't tell if the 0.167 Hz infrasonic component was produced directly or is some beat frequency between those other lobes.

Now bass distortion is the least audible of all, and this could just be the underlying mechanism that leads to that overall very mild warm tilt, but still... no well-behaved DAC should do this. What if it causes weird interactions with other frequencies depending on the song (and song section!) being played, resulting in audible artifacts beyond just a vague tilt? Could we see something if we put a song through and DeltaWave it vs. the original file?
View attachment 441501
OK, same vaguely warm tilt going into the treble, before the noise let through by the filter starts to dominate... but also massive sub-bass spikes. Like, even if these aren't audible because my headphones can't produce them at the right volume, I'd bet they can affect how the rest of the frequencies are presented, by periodically pushing the membrane too close to xmax.

Also, the delta of spectra in spectrogram form gives another hint: the KA17's problems seem to come out more in the simpler sections of the song with the more sparse spectra (wherever you're seeing the thicker red lines in the sub-bass and extra energy shades going up across the whole band is where most instruments and voices went quiet).
View attachment 441506

Was this a one-off? What if I re-record the same song today?
View attachment 441507
Nope, pretty much the same. Weird sub-bass spikes galore. (Notice the fit quality doesn't make a difference, since we're not analyzing the time-domain delta, only the spectral delta.)

So going forward what this leaves me with is I should try more songs, and especially focus on more minimalistic ones - less symphonic, less white-noise-like - and check their spectra in DeltaWave, to find the best section of the best song to put in my ABX test later.

But regardless of what result I will get there, I think these spectrograms already show the hypothesis that "all you need is a frequency sweep or white noise test" is far from correct: even at today's level of technology DAC/amps can respond quite differently depending on the material they're being fed, showing changes in tonality even within the same song.

Wow this is quite interesting, this is a different way of measuring things then we have been doing here. It is also something that I have wondered about for a while; if there were more ways to measure differences in DACs, even beyond what we can hear. Also might shed some light on why some people "prefer" certain DAC's.

 

[Jimster480]

In attachment 10 seconds excerpt from "Lady Gaga / Mayhem / 01. Disease" in 16 and 8 bits.

(I know, I know, it would be easily audible at the beginning of the song )

So I listened to it and it is very hard to tell which one is which. I didn't try it using my better resolving headphones though... only my Denon Ah-MM400's. This song (or atleast this part of it) has an extremely low dynamic range, so it doesn't surprise me that it is hard to tell between 8 and 16 bit.

 

[solderdude]

Also measurements change as the DAC ages out.

What would be the mechanism responsible for that, is there objective proof for that ?

Play a tight recording of a Stradivarius, then distort it to the same degree....yes. Noise...how can you not hear noise???

Noise in DACs is below audible levels and when one does hear noise it is usually in the recording. Noise in recordings made with microphones that are not gated will be magnitudes higher than the self noise of DAC circuits.

Some people think their old LP sounds great. Can they hear the difference between 86db and 91db SNR? Can we???

There is a hearing threshold. Noise can be shaped differently (think white/pink/brown noise) which changes audibility and 'annoyance factor'.
It is quite possible to hear 5dB noise differences in quiet passages especially when the spectrum differs.

 

[donjoe0]

I have wondered about for a while; if there were more ways to measure differences in DACs, even beyond what we can hear. Also might shed some light on why some people "prefer" certain DAC's.

I'm not trying to go that far into the paint right now and determine if some people prefer some DACs based on information "perceived but not heard", I'm trying to stay in the realm of audibility but also to find better approximations of its limits. What differences can be heard but have been routinely ignored by measurements-reviewers? And I've found it quite weird to see as little focus on frequency response as I've seen in measurements-reviews, while I had the impression almost everyone who takes a scientific approach to analyzing audio quality in reproduction devices agrees that FR is easily the most important metric of all.

More evidence on "DACs today do not have a sound signature": let me introduce the FiiO/Snowsky Retro Nano as it performs in its main operating mode, i.e. as a Bluetooth receiver running LDAC. Same song as before, delta vs. original file:

@16-bit / 44 kHz / 909 kbps (locked to best quality)

@16-bit / 48 kHz / 990 kbps

@24-bit / 96 kHz / 990 kbps

Noisier results at the higher sampling rates, but it's pretty clear it's consistently showing about a 1-dB(!) scoop of pretty wide Q in the mid-mids/high-mids and some infrasonic noise like we saw with the KA17.
FiiO do love their infrasonics it seems:

Good thing there's a PEQ in this one, I'll be using it to fix its own FR, allowing my 'regular' PEQ in Neutron Player to stay allocated to fixing headphones.