MLXXX Posted January 20, 2023 Posted January 20, 2023 3 hours ago, andyr said: Which is why I can't help thinking that the "more information" that's available from higher sampling rates in a digital recording ... similarly delivers a benefit. Our eyesight is sensitive to a particular range of wavelengths of light; similarly our hearing covers only a range of wavelengths of sound. There is no point in presenting wavelengths to our sensory organs that lie outside their range of detection. For example, prescription glasses can be purchased with the option of a UV coating to filter out the ultraviolet light so as to offer protection against harmful radiation. This coating does not interfere with your ability to see visible light, or fine detail of visible light. The UV "information" filtered out is useless to the human eye. On the other hand, bees and birds have eyesight that can use UV information. The human cochlea can respond to audio frequencies over the approximate range 20Hz to 20kHz (the upper limit in particular reducing as we age). There are no receptors in the cochlea for supersonic frequencies. Supersonic "information" is useless for the human ear. On the other hand, dogs and bats have hearing that can use that information.
andyr Posted January 20, 2023 Posted January 20, 2023 11 minutes ago, MLXXX said: The human cochlea can respond to audio frequencies over the approximate range 20Hz to 20kHz (the upper limit in particular reducing as we age). There are no receptors in the cochlea for supersonic frequencies. Supersonic "information" is useless for the human ear. On the other hand, dogs and bats have hearing that can use that information. The point I was trying to make was about how an LP track cut for 45rpm sounds better than the same recording cut for 33rpm playing. This has nothing to do with 45rpm delivering higher frequencies - rather, the higher speed results in more faithful delivery of micro-factors like the 'air' around the instruments ... and the ambiance of the recording space. It's already been pointed out to me that my assumption that digital recordings made at, say, 96kHz rather than 44.1kHz must have more information about the analogue waveform being recorded ... is misguided.
MLXXX Posted January 20, 2023 Posted January 20, 2023 3 minutes ago, andyr said: It's already been pointed out to me that my assumption that digital recordings made at, say, 96kHz rather than 44.1kHz must have more information about the analogue waveform being recorded ... is misguided. Fair enough. * * * I remember setting up my system for DVD audio in the very early 2000's, going into the city to acquire a couple of fairly expensive DVD audio discs, and being very excited with the idea of playing the discs for the first time and being able to switch between quadraphonic 96kHz 24-bit sound and ordinary resolution stereo. The marketing had promised additional detail when switching to high resolution. It was a tremendous disappointment. The rear channels did add some ambience, but the front channels sounded the same. There was no "added detail". Ever since, I have been very sceptical about claims that high-res formats sound better by reason of a higher sample rate or bit depth.
davewantsmoore Posted January 20, 2023 Posted January 20, 2023 4 hours ago, andyr said: Which is why I can't help thinking that the "more information" that's available from higher sampling rates in a digital recording ... similarly delivers a benefit. There isn't "extra information" when looking at the same range of frequencies. If you look at the frequencies between 0 and 20,000 Hz. ..... a 48khz sampling rate represent them with the same amount of information than a 96khz sampling rate does.... and with the same amount of information than a 192khz sampling rate does.... and with the same amount of information than a 384khz sampling rate does. The higher sampling rates don't give "extra information" to lower frequencies.... they only allow the storage of higher frequencies. 1
andyr Posted January 20, 2023 Posted January 20, 2023 13 minutes ago, davewantsmoore said: The higher sampling rates don't give "extra information" to lower frequencies.... they only allow the storage of higher frequencies. That's what I'm learning, Dave. Yet the FLAC file of an LP side recorded at 96kHz is about twice the length of the FLAC file when the LP side was recorded at 48kHz! (I've done it and compared the file sizes.) So what is all this extra data (being used) for?
aussievintage Posted January 20, 2023 Posted January 20, 2023 7 minutes ago, andyr said: So what is all this extra data (being used) for? wasted bandwidth 1
Ars Paart Posted January 20, 2023 Posted January 20, 2023 29 minutes ago, aussievintage said: wasted bandwidth unless you're a bat.
March Audio Posted January 20, 2023 Posted January 20, 2023 (edited) 2 hours ago, andyr said: That's what I'm learning, Dave. Yet the FLAC file of an LP side recorded at 96kHz is about twice the length of the FLAC file when the LP side was recorded at 48kHz! (I've done it and compared the file sizes.) So what is all this extra data (being used) for? For the most part recording low level noise above 20kHz. Even if it were silence it would still take up extra file space. I will post some plots later of recordings and their content above 20kHz. Edited January 20, 2023 by March Audio
andyr Posted January 20, 2023 Posted January 20, 2023 1 hour ago, March Audio said: Even if it were silence it would still take up extra file space. Why is this, Alan? I can understand that when the stylus is on the groove, the recording process is picking up the noise of the stylus rushing along the groove - so valid data points will be recorded. But what if I recorded 5 minutes of silence - with the armlift engaged (so the stylus is not in the groove). Surely this would have a minimal number of recorded data points - as the (lack of!) noise is not changing? So the data file should be very short.
bob_m_54 Posted January 20, 2023 Posted January 20, 2023 2 hours ago, andyr said: Why is this, Alan? I can understand that when the stylus is on the groove, the recording process is picking up the noise of the stylus rushing along the groove - so valid data points will be recorded. But what if I recorded 5 minutes of silence - with the armlift engaged (so the stylus is not in the groove). Surely this would have a minimal number of recorded data points - as the (lack of!) noise is not changing? So the data file should be very short. The number of data points would be the same, but their values, which still tale up data space, would equate to silence. 24bit/96KHz of silence is still bigger in file size that 16bit/44.1Khz of silence, for the same track length..
bob_m_54 Posted January 20, 2023 Posted January 20, 2023 23 hours ago, andyr said: OK, so why does faster speed sound better? Does it?
andyr Posted January 20, 2023 Posted January 20, 2023 13 minutes ago, bob_m_54 said: The number of data points would be the same, but their values, which still tale up data space, would equate to silence. 24bit/96KHz of silence is still bigger in file size that 16bit/44.1Khz of silence, for the same track length.. Aah, OK - thanks, Bob. I will do the experiment in a few days (just waiting for a cable to arrive). A 5 min recording - 300 seconds, timed by my stopwatch.
andyr Posted January 20, 2023 Posted January 20, 2023 12 minutes ago, bob_m_54 said: Does it? It does, Bob. As I said, I have a Test record with the same recorded track but cut: 33rpm on one side of the LP, and 45rpm on the other.
bob_m_54 Posted January 20, 2023 Posted January 20, 2023 1 minute ago, andyr said: It does, Bob. As I said, I have a Test record with the same recorded track but cut: 33rpm on one side of the LP, and 45rpm on the other. OK
andyr Posted January 20, 2023 Posted January 20, 2023 3 minutes ago, bob_m_54 said: OK You seem to be someone who has had little - if any - experience with vinyl, Bob? Whereas I bought my first TT in 1971 - and have continued listening to vinyl ever since. Although, I must admit that now, I am starting to rip my LPs, to store them on SSD - so I can use the convolution capabilities of Roon to add a "linear phase" (FIR filter) overlay, to correct the phase problems associated with the IIR filters used in my spkrs.
bob_m_54 Posted January 20, 2023 Posted January 20, 2023 3 minutes ago, andyr said: You seem to be someone who has had little - if any - experience with vinyl, Bob? Whereas I bought my first TT in 1971 - and have continued listening to vinyl ever since. Although, I must admit that now, I am starting to rip my LPs, to store them on SSD - so I can use the convolution capabilities of Roon to add a "linear phase" (FIR filter) overlay, to correct the phase problems associated with the IIR filters used in my spkrs. I don't know where you get that idea, but I don't have any 12" 45rpm discs, or 45rpm of the same master as the album (33 1/3 rpm) tracks to compare.. But... it still has no bearing on digital music files, in relation to bit depth and sample rate..
Volunteer sir sanders zingmore Posted January 20, 2023 Volunteer Posted January 20, 2023 4 minutes ago, bob_m_54 said: But... it still has no bearing on digital music files, in relation to bit depth and sample rate.. Indeed.. it's probably too late but can we please keep to the topic (hint: the topic is not vinyl) 2 1
andyr Posted January 20, 2023 Posted January 20, 2023 4 minutes ago, bob_m_54 said: I don't know where you get that idea, but I don't have any 12" 45rpm discs, or 45rpm of the same master as the album (33 1/3 rpm) tracks to compare. Aah, OK Bob. It's just that I've never before come across anyone who doesn't think that 45rpm sounds better than 33rpm. 4 minutes ago, bob_m_54 said: But... it still has no bearing on digital music files, in relation to bit depth and sample rate.. But given that theory ... it must not be possible to get any better SQ than CD standard (16bit / 44.1kHz) - right? Which IME ... is simply not the case.
andyr Posted January 20, 2023 Posted January 20, 2023 (edited) 9 minutes ago, sir sanders zingmore said: (hint: the topic is not vinyl) Shure, Trev - but the topic is (surely?) ... is there any better SQ than that which is delivered by 16bit/44.1kHz CD-standard recordings! My (listening) experience is that there is - but nobody seems to be able to explain why. Edited January 20, 2023 by andyr
bob_m_54 Posted January 20, 2023 Posted January 20, 2023 6 minutes ago, andyr said: But given that theory ... it must not be possible to get any better SQ than CD standard (16bit / 44.1kHz) - right? Propose a theory, and we can debate it. But, don't try to relate digital music formats with analog music formats (ie bit depth, sampling freq VS rpm, ips), when trying to explain what you mean by "better SQ" whatever that means.. 1
andyr Posted January 20, 2023 Posted January 20, 2023 1 minute ago, bob_m_54 said: when trying to explain what you mean by "better SQ" whatever that means.. If "better SQ" is not clear to you Bob ... I'm afraid I cannot explain it to you. To me it's exactly like the classic definition of pornography in a well-known 1960s US Supreme Court case ... "I can't define it - but I know it when I see it".
bob_m_54 Posted January 20, 2023 Posted January 20, 2023 2 minutes ago, andyr said: If "better SQ" is not clear to you Bob ... I'm afraid I cannot explain it to you. There's really no need... It's way too subjective to clog up this thread with such tedium...
LHC Posted January 20, 2023 Posted January 20, 2023 1 hour ago, andyr said: Shure, Trev - but the topic is (surely?) ... is there any better SQ than that which is delivered by 16bit/44.1kHz CD-standard recordings! My (listening) experience is that there is - but nobody seems to be able to explain why. If you are interested in this question may I suggests you follow the work and outputs of the AES TECHNICAL COMMITTEE on 'HIGH RESOLUTION AUDIO' (https://www.aes.org/technical/hra/) In 2016 this HRA commissioned a meta-study on scientific evidence for hi res audio resulting in this paper by JOSHUA D. REISS (https://qmro.qmul.ac.uk/xmlui/bitstream/handle/123456789/13493/Reiss A Meta-Analysis of High Resolution 2016 Published.pdf) Quoting its finding "Results showed a small but statistically significant ability of test subjects to discriminate high resolution content, and this effect increased dramatically when test subjects received extensive training." I think a colloquial way of stating Reiss finding is that 'some people can hear the differences in some high res audio content some of the time'. AFAIK there is no consensus explanation of this finding; and to this day remains an open scientific question. Unfortunately this does not appear to be a very active area of scientific research, but notably there are ongoing Japanese researchers publishing in this area. For example the following Japanese paper (https://web.archive.org/web/20210715091831id_/https://www.jstage.jst.go.jp/article/jjppp/38/3/38_2003br/_pdf) has this abstract: "High-resolution audio has a higher temporal and/or depth resolution than compact disks (CDs). Several researchers have suggested that inaudible high-frequency components of high-resolution audio might influence listeners’ psychophysiological states. Two types of digital sound sources with the identical frequency structure (＜22 kHz) were created at different sampling rates (192 kHz and 44.1 kHz) by filtering out inaudible highfrequency components of an original sound source, which was an excerpt of natural environmental sounds recorded in 192-kHz/24-bit format. Twenty-four university students listened to the three sounds in a random order for five minutes each. Results indicated that the 192-kHz sound source compared to the 44.1-kHz sound source induced higher power in the theta (4.0‒8.0 Hz) and slow alpha (8.0‒10.5 Hz) bands of the electroencephalogram. However, no apparent differences were found in sound quality or subjective mood. These results suggest that digital sound sources with a higher sampling frequency than CDs influence the physiological state of listeners, although the difference might not be consciously perceived." Another study by the Japanese in 2020 (https://www.nature.com/articles/s41598-020-78889-9) Abstract "High-resolution digital audio is believed to produce a better listening experience than the standard quality audio, such as compact disks (CDs) and digital versatile disks (DVDs). One common belief is that high-resolution digital audio is superior due to the higher frequency (> 22 kHz) of its sound components, a characteristic unique to this audio. This study examined whether sounds with high-frequency components were processed differently from similar sounds without these components in the auditory cortex. Mismatch negativity (MMN), an electrocortical index of auditory deviance detection in sensory memory, was recorded in young adults with normal hearing (N = 38) using two types of white noise bursts: original sound and digitally filtered sound from which high-frequency components were removed. The two sounds did not produce any MMN response and could not be discriminated behaviourally. In conclusion, even if high-resolution audio is superior to the standard format, the difference is apparently not detectable at the cortical level." While these may seem like negative results thankfully research continues (albeit slowly).
March Audio Posted January 20, 2023 Posted January 20, 2023 (edited) 6 hours ago, andyr said: Why is this, Alan? I can understand that when the stylus is on the groove, the recording process is picking up the noise of the stylus rushing along the groove - so valid data points will be recorded. But what if I recorded 5 minutes of silence - with the armlift engaged (so the stylus is not in the groove). Surely this would have a minimal number of recorded data points - as the (lack of!) noise is not changing? So the data file should be very short. With cd the voltage level of the analogue signal is recorded 44100 times every second. The voltage level is encoded as a 16 bit binary word. This is a decimel level between 0 and 65535. It doesn't matter if the signal level is low , high or zero, the 16 bit word is recorded 44100 times a second regardless. It's a fixed amount of data regardless of what the audio signal is doing. 16 bits * 44100 * 2 channels = 1411.2 kbits per second, or 174.6 kbytes per second. 24bit 96kHz is a 24 bit word (decimal 0 to 16777215) recorded 96000 times every second. That's 4,608 kbits/s or 576 kbytes/s. It's a waste as most of that data is recording noise. Mostly noise above 20kHz and below 18bits. You will find almost no recordings that have any useful musical information below 18 bits. Those last 6 bits are just permanently set high with noise. Edited January 20, 2023 by March Audio
March Audio Posted January 20, 2023 Posted January 20, 2023 (edited) 4 hours ago, andyr said: Aah, OK - thanks, Bob. I will do the experiment in a few days (just waiting for a cable to arrive). A 5 min recording - 300 seconds, timed by my stopwatch. No need. We can calculate it. Note this is uncompressed wav not flac. 44100 (samples per second) * 16 (bits) * 2 (channels) * 300 (seconds) = 423,360 kbits or 52920 kbytes or 59.92 Mb 96000 * 24 * 2 * 300 = 1,382,400kbits or 172,800 kbytes or 172.8 Mb. Note you will get slightly different numbers if you define kilo as 1024 as opposed to 1000. Edited January 20, 2023 by March Audio 1
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