Popular Post Jud Posted February 14, 2020 Popular Post Share Posted February 14, 2020 10 minutes ago, bilboda said: Well, I view your statement as unsupported, likely submitted for controversy only and thus false,until proven otherwise.🤨 Hi @bilboda - I think what's meant is that you wouldn't have a 26 bit signal to noise figure, true dynamic range, or however you want to express it, unless you immersed the DAC in a bath of liquid nitrogen (helium?), and perhaps not even then due to quantum effects (shot noise). So the -155dB is a non standard and misleading measurement as to this DAC's true comparative performance, posted either deliberately and knowingly, or in error out of ignorance. mansr, semente, Superdad and 1 other 4 One never knows, do one? - Fats Waller The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein Computer, Audirvana -> optical Ethernet to Fitlet3 -> Fibbr Alpha Optical USB -> iFi NEO iDSD DAC -> Apollon Audio 1ET400A Mini (Purifi based) -> Vandersteen 3A Signature. Link to comment
bilboda Posted February 14, 2020 Share Posted February 14, 2020 He is apparently aware of the noise issue and has addressed this. What do you think of the solution? I have only read a claim of 24 bit range. 26 bit is being inferred by the reader? Link to comment
Jud Posted February 14, 2020 Share Posted February 14, 2020 1 minute ago, bilboda said: He is apparently aware of the noise issue and has addressed this. What do you think of the solution? I have only read a claim of 24 bit range. 26 bit is being inferred by the reader? There is no 24 bit range. That's the internal mathematics of the digital operations within the device, essentially how many decimal places it uses for its calculations. I've read about studio equipment that uses 80 bit internal mathematics for some DSP operations. The true dynamic range or signal to noise can be given in decibels or bits, 6 dB per bit. So just divide the published -155dB "noise floor" by 6 and you get nearly 26 bits. semente 1 One never knows, do one? - Fats Waller The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein Computer, Audirvana -> optical Ethernet to Fitlet3 -> Fibbr Alpha Optical USB -> iFi NEO iDSD DAC -> Apollon Audio 1ET400A Mini (Purifi based) -> Vandersteen 3A Signature. Link to comment
bilboda Posted February 14, 2020 Share Posted February 14, 2020 "The result of this process is an extremely high linearity, right down to -140 dB, which gives our products a realistic 24 bit dynamic range." https://www.sonnet-audio.com/Morpheus.html Link to comment
Popular Post mansr Posted February 14, 2020 Popular Post Share Posted February 14, 2020 "Noise Floor -155 dB related to 2 Volt RMS" https://www.sonnet-audio.com/Morpheus_specs.html semente and Jud 2 Link to comment
Popular Post mansr Posted February 14, 2020 Popular Post Share Posted February 14, 2020 Here's a power spectrum of white noise at 1 LSB with 24-bit samples: Notice how the level of the "floor" is roughly at the -180 mark on the y axis. The total noise power, however, is obtained by integrating across this spectrum. If we do this, we get a value of -143 dB. Jud, opus101 and semente 1 2 Link to comment
bilboda Posted February 14, 2020 Share Posted February 14, 2020 143? 150? not very different and I suspect the spec was measured not calculated. You can speculate all you want but until you know how it was measured and duplicate it, (or correct it) you can't know. So if you do want to know, you should ask. Link to comment
barrows Posted February 14, 2020 Share Posted February 14, 2020 2 hours ago, bilboda said: Well, I view your statement as unsupported, likely submitted for controversy only and thus false,until proven otherwise.🤨 The burden of proof would fall to the company making the claim, especially in a case where the claim is it for far better resolution than is understood by to be possible with currently available parts. SO/ROON/HQPe: DSD 512-Sonore opticalModuleDeluxe-Signature Rendu optical with Well Tempered Clock--DIY DSC-2 DAC with SC Pure Clock--DIY Purifi Amplifier-Focus Audio FS888 speakers-JL E 112 sub-Nordost Tyr USB, DIY EventHorizon AC cables, Iconoclast XLR & speaker cables, Synergistic Purple Fuses, Spacetime system clarifiers. ISOAcoustics Oreas footers. SONORE computer audio | opticalRendu | ultraRendu | microRendu | Signature Rendu SE | Accessories | Software | Link to comment
Jud Posted February 14, 2020 Share Posted February 14, 2020 50 minutes ago, bilboda said: 143? 150? not very different and I suspect the spec was measured not calculated. You can speculate all you want but until you know how it was measured and duplicate it, (or correct it) you can't know. So if you do want to know, you should ask. As you'll see from @mansr's graph, the question is not whether the -155dB was measured or calculated, but whether the measurement was taken in standard fashion or in a way that was mistakenly or deliberately misleading. Actually that isn't really a question. We know the measurement was not done in standard fashion because the result is not possible under those conditions. One never knows, do one? - Fats Waller The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein Computer, Audirvana -> optical Ethernet to Fitlet3 -> Fibbr Alpha Optical USB -> iFi NEO iDSD DAC -> Apollon Audio 1ET400A Mini (Purifi based) -> Vandersteen 3A Signature. Link to comment
bilboda Posted February 14, 2020 Share Posted February 14, 2020 I guess speculation is the order of the day then as no one really wants to know, I have to turn to the right and get back to work, y'all have a great Valentine's/Friday. Link to comment
mansr Posted February 14, 2020 Share Posted February 14, 2020 21 minutes ago, bilboda said: 143? 150? not very different and I suspect the spec was measured not calculated. You can speculate all you want but until you know how it was measured and duplicate it, (or correct it) you can't know. So if you do want to know, you should ask. It is impossible to have a noise level lower than -144 dB with 24-bit samples. The residual noise when playing digital silence or a carefully chosen ideal test signal could in theory be lower, but that's hardly interesting. For arbitrary signals, the -144 dB figure is a hard mathematical limit. If a measurement suggests otherwise, that measurement is flawed. If the -155 dB figure is actually the noise spectral density, it corresponds to an effective resolution of 16.5–18.5 bits depending on sample rate. At least the lower end of this range is realistic for this type of DAC. semente 1 Link to comment
Popular Post Jud Posted February 14, 2020 Popular Post Share Posted February 14, 2020 From https://www.analog.com/media/en/training-seminars/tutorials/MT-001.pdf , an explanation for the graph @mansr shows above: "SNR, PROCESS GAIN, AND FFT NOISE FLOOR RELATIONSHIPS "Figure 6 shows the FFT output for an ideal 12-bit ADC. Note that the average value of the noise floor of the FFT is approximately 107 dB below full-scale, but the theoretical SNR of a 12-bit ADC is 74 dB. The FFT noise floor is not the SNR of the ADC, because the FFT acts like an analog spectrum analyzer with a bandwidth of fs/M, where M is the number of points in the FFT. The theoretical FFT noise floor is therefore 10log10(M/2) dB below the quantization noise floor due to the processing gain of the FFT. "In the case of an ideal 12-bit ADC with an SNR of 74 dB, a 4096-point FFT would result in a processing gain of 10log10(4096/2) = 33 dB, thereby resulting in an overall FFT noise floor of 74 + 33 = 107 dBc. In fact, the FFT noise floor can be reduced even further by going to larger and larger FFTs; just as an analog spectrum analyzer's noise floor can be reduced by narrowing the bandwidth. When testing ADCs using FFTs, it is therefore important to ensure that the FFT size is large enough so that the distortion products can be distinguished from the FFT noise floor itself. Averaging a number of FFTs does not further reduce the noise floor, it simply reduces the variations between the individual noise spectral component amplitudes." Edit: So for example if Sonnet used a 4096-point FFT to measure its "noise floor," the SNR would be more like -122dB, or about 20 bits - quite nice but not earthshaking. Of course it could have used an FFT with more points in its measurement and the SNR would be worse. Superdad, semente and opus101 3 One never knows, do one? - Fats Waller The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein Computer, Audirvana -> optical Ethernet to Fitlet3 -> Fibbr Alpha Optical USB -> iFi NEO iDSD DAC -> Apollon Audio 1ET400A Mini (Purifi based) -> Vandersteen 3A Signature. Link to comment
Popular Post Jud Posted February 14, 2020 Popular Post Share Posted February 14, 2020 So it appears that Sonnet has taken advantage of terminology to leave the impression that its DAC is extraordinarily quiet, when in fact it may just as easily not be. First Sonnet takes advantage of the confusion between "bits" as used in internal DAC processing and "bits" as an expression of digital audio dynamic range equal to 6 dB per bit. It talks about having a 24 bit DAC (most these days are 32 bit) and dynamic range together, to leave the impression the DAC is capable of 24 bits of dynamic range, when that is physically impossible for a 24 bit DAC. That would be claiming perfectly silent electronics, meaning first of all that they would be at an operating temperature of absolute zero (-273.15 degrees Celsius), and second that the electronics did not operate in accordance with the same laws of quantum physics that everything else in the universe does. Second, Sonnet talks about a "noise floor" of -155dB, but as we can see from the reference in my previous post, the "noise floor" is not a reflection just of the signal to noise ratio, but also of an arbitrarily large processing gain depending on the number of points in the FFT used for the measurement. Thus Sonnet substitutes for a true SNR figure a similar-sounding "noise floor" measurement that is not at all the same. semente and Superdad 2 One never knows, do one? - Fats Waller The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein Computer, Audirvana -> optical Ethernet to Fitlet3 -> Fibbr Alpha Optical USB -> iFi NEO iDSD DAC -> Apollon Audio 1ET400A Mini (Purifi based) -> Vandersteen 3A Signature. Link to comment
Account Closed Posted February 14, 2020 Share Posted February 14, 2020 Now if we only had a room quiet enough and a recording good enough to take advantage of even standard 16 bit tech. Jud 1 Link to comment
mansr Posted February 14, 2020 Share Posted February 14, 2020 41 minutes ago, Jud said: Second, Sonnet talks about a "noise floor" of -155dB, but as we can see from the reference in my previous post, the "noise floor" is not a reflection just of the signal to noise ratio, but of an arbitrarily large processing gain depending on the number of points in the FFT used for the measurement. Thus Sonnet substitutes for a true SNR figure a similar-sounding "noise floor" measurement that is not at all the same. The correct way to use an FFT is to divide the raw values by the bin width. That way the values give the actual spectral density regardless of the number of bins, and the level of the "floor" doesn't change. If they didn't even do this when producing the -155 dB figure, that number is quite meaningless. Properly scaled, noise density is a useful metric often found in datasheets. Of course, they label it as such and don't try to pass it off as something else. Link to comment
Jud Posted February 14, 2020 Share Posted February 14, 2020 11 minutes ago, bobflood said: Now if we only had a room quiet enough and a recording good enough to take advantage of even standard 16 bit tech. I have a quiet listening room in an exurban setting (about 3 miles from the nearest town of 5000) in a very well insulated house (we lost power and thus heat for 24 hours in a winter windstorm with 50-60mph winds and temperatures below freezing; indoor temperatures dropped from their setpoints of 69-70 degrees F to 67-68 degrees). The background level is about 30dB. semente 1 One never knows, do one? - Fats Waller The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein Computer, Audirvana -> optical Ethernet to Fitlet3 -> Fibbr Alpha Optical USB -> iFi NEO iDSD DAC -> Apollon Audio 1ET400A Mini (Purifi based) -> Vandersteen 3A Signature. Link to comment
Miska Posted February 14, 2020 Share Posted February 14, 2020 When the environment is really quiet, it becomes really disturbing because you start hearing your own body organs. Your own breathing begins to sound loud, etc. Signalyst - Developer of HQPlayer Pulse & Fidelity - Software Defined Amplifiers Link to comment
Account Closed Posted February 14, 2020 Share Posted February 14, 2020 21 minutes ago, Jud said: I have a quiet listening room in an exurban setting (about 3 miles from the nearest town of 5000) in a very well insulated house (we lost power and thus heat for 24 hours in a winter windstorm with 50-60mph winds and temperatures below freezing; indoor temperatures dropped from their setpoints of 69-70 degrees F to 67-68 degrees). The background level is about 30dB. That sounds about right. I have measured mine as low as 30bB but most of the time it is in the low to mid 30 range. I don't think most appreciate that any sound that our brains can process (including music) must first emerge from that background din (noise). I read some interesting research that showed that our brains don't do well in a really quiet environment. They put people in an anechoic chamber and if memory serves they started having hallucinations after a while. Link below: https://www.smithsonianmag.com/smart-news/earths-quietest-place-will-drive-you-crazy-in-45-minutes-180948160/ My point being that an extreme dynamic range is not really very useful and is rarely if ever used to its full capacity. The low end is lost and the high end would be dangerous. That said, most recordings especially "loudness wars" recordings are so compressed that they use only a fraction of what would be pleasing, safe and easily available. Link to comment
barrows Posted February 14, 2020 Share Posted February 14, 2020 36 minutes ago, bobflood said: . I don't think most appreciate that any sound that our brains can process (including music) must first emerge from that background din (noise) Actually, I do not think this is correct at all? Humans can hear sounds below the noise floor (the in room noise floor), as the brain can sort these sounds from noise, right? Think about LP playback, one can certainly hear sounds at levels well below that of the surface noise: this process is usually helped if the sound in question is well known by the brain already (not necessarily the same sound, but a "like" sound, such as the sound of a bell). Also consider dither, I am sure @mansr has a good explanation of this. SO/ROON/HQPe: DSD 512-Sonore opticalModuleDeluxe-Signature Rendu optical with Well Tempered Clock--DIY DSC-2 DAC with SC Pure Clock--DIY Purifi Amplifier-Focus Audio FS888 speakers-JL E 112 sub-Nordost Tyr USB, DIY EventHorizon AC cables, Iconoclast XLR & speaker cables, Synergistic Purple Fuses, Spacetime system clarifiers. ISOAcoustics Oreas footers. SONORE computer audio | opticalRendu | ultraRendu | microRendu | Signature Rendu SE | Accessories | Software | Link to comment
Popular Post mansr Posted February 14, 2020 Popular Post Share Posted February 14, 2020 1 minute ago, barrows said: Actually, I do not think this is correct at all? Humans can hear sounds below the noise floor, as the brain can sort these sounds from noise, right? Think about LP playback, one can certainly hear sounds at levels well below that of the surface noise: this process is usually helped if the sound in question is well known by the brain already (not necessarily the same sound, but a "like" sound, such as the sound of a bell). This is another variant of the same confusion. The total noise power of TPDF dither at the 16-bit level is roughly -92 dB. The spectral density, however, is around -135 dB/Hz. If we create a 1 kHz tone at -100 dBFS and dither it to 16-bit precision, we get this spectrum: The tone is clearly visible above the noise. If we play this signal on a decent DAC with the volume turned up high, we can hear a distinct tone as well as some hiss. This is because the tone has much higher intensity than the noise in the immediately surrounding frequencies. The ear separates sounds by frequency much like an FFT, so it's no surprise it too can detect such signals. When people talk about hearing below or into the noise, this is what they (perhaps unknowingly) mean. There is nothing special, mysterious, magical, or in any way remarkable about it. 1 minute ago, barrows said: Also consider dither, I am sure @mansr has a good explanation of this. Dither is just noise with a specific purpose. In the context of this discussion, it requires no special consideration. Miska and semente 2 Link to comment
Account Closed Posted February 14, 2020 Share Posted February 14, 2020 56 minutes ago, mansr said: This is another variant of the same confusion. The total noise power of TPDF dither at the 16-bit level is roughly -92 dB. The spectral density, however, is around -135 dB/Hz. If we create a 1 kHz tone at -100 dBFS and dither it to 16-bit precision, we get this spectrum: The tone is clearly visible above the noise. If we play this signal on a decent DAC with the volume turned up high, we can hear a distinct tone as well as some hiss. This is because the tone has much higher intensity than the noise in the immediately surrounding frequencies. The ear separates sounds by frequency much like an FFT, so it's no surprise it too can detect such signals. When people talk about hearing below or into the noise, this is what they (perhaps unknowingly) mean. There is nothing special, mysterious, magical, or in any way remarkable about it. Dither is just noise with a specific purpose. In the context of this discussion, it requires no special consideration. Thanks, I stand corrected. I guess I knew that one can hear below the ambient noise but I did not express what I was trying to get across clearly. I remember something I read years ago said that for something to reach the level of perception below the noise floor it had to be differentiated from the noise for the brain to register it otherwise it would be ignored as noise. This requires more brain processing than sound above the noise floor. This fits in with your explanation above. Thanks again. Link to comment
Popular Post fas42 Posted February 14, 2020 Popular Post Share Posted February 14, 2020 Back in the real world, 😉, 16 bits, and something approaching 90dB resolution, is all that's required for a listening experience that can be "better than real life" - chasing numbers might be fun, as an intellectual exercise, but has almost nothing to do with achieving emotionally satisfying dynamics from audio reproduction ... Account Closed and buonassi 2 Link to comment
asdf1000 Posted February 15, 2020 Share Posted February 15, 2020 10 hours ago, Miska said: When the environment is really quiet, it becomes really disturbing because you start hearing your own body organs. Your own breathing begins to sound loud, etc. Like with earplugs in. Link to comment
asdf1000 Posted February 15, 2020 Share Posted February 15, 2020 On 1/26/2020 at 7:42 AM, audiofool said: I've emailed FiiO, is there any other way to determine if it operates in direct mode? They have a block diagram on their site showing a second order low pass filter after the dac and before the volume control followed by OPA1642 and TPA6120. https://fiio.com/k5pro Hi, did they reply? Link to comment
semente Posted February 18, 2020 Author Share Posted February 18, 2020 On 2/14/2020 at 12:12 PM, bilboda said: He is apparently aware of the noise issue and has addressed this. What do you think of the solution? I have only read a claim of 24 bit range. 26 bit is being inferred by the reader? Fantasy. "Science draws the wave, poetry fills it with water" Teixeira de Pascoaes HQPlayer Desktop / Mac mini → Intona 7054 → RME ADI-2 DAC FS (DSD256) Link to comment
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