Jan is right, of course. Sounds Better falls into pretty clear categories, which of course because we audiophilic monkeys are complex critters, are often tangled and mixed in the same sentence and sometimes, same phrase!:
1: aggrandizement - money spent on expensive stuff, which, when placed into service delivers the pablum (placebo) effect, with the buyer (especially) and her horde falling into line. "Transients much more detailed, and bass is incredibly more open and transparent on the broad soundstage. The speakers utterly disappeared, etc..."
2: different = better = different - well, this is easy. ANY difference except for the most egregious adding-of-noise (and then, incredibly, even then, for some listeners) is viewed as better. Glacial-speed "knob twiddling" through making basically irreversible system changes. One can't ungrind the edge of a cd, easily.
3: amplitude bias - maybe the most common of all! When "B" is put into service, virtually all operators/listeners will "turn up the volume a bit" in order to detect what supposedly is the improvement. Well, we've got deep psychological bias that in general, unless painful, a bit louder = a bit better. Try it with a friend sometime! Play a CD at volume setting 5 (say). Take the CD out, make a show of putting another one (but really the first one) back in, and set the volume to 5.5 ... just a wee bit louder. The friend will almost inevitably say it is way better.
4: completion bias - now, without changing the volume, do the same thing with a different CD. Play a part of a track. DON'T let the track finish! Take the CD out, make a show of getting a duplicate (somehow magic-unicorn-dust improved, but actually the exact same CD), and inserting it. Find the same track ... and play it again. This time, let the track finish. Blam... 99% of listeners will comment favorably about "B". They don't understand their inner feeling of being more satisfied when the passage is allowed to complete, and mistake such better feelings for better sound. Ah... we monkeys.
5: repetition bias - EVEN if one lets both passage "A" and "B" complete, for music that is exciting, harmonic and edgy, generally people much prefer the 2nd playback. Same deal, "make a show of it" exchanging (but not) the CD. Psychologists found that 5 out of 7 people (1970s) prefer the 2nd repetition over the first. With all knobs exactly untouched! Oh well...
6: Academic Bias - when the experimenter is responsible for making an "informed decision", involving technological words-of-art, diagrams and so on. We audiophiles are especially subject to this poor canard: Even though secretly there may be a straight wire going from input to output of a preamplifier (as an example), so long as there's a big write up of cascodes, and balanced current sources, and Sziklai complimentary signal path active devices, and capacitor (or whatever bogey) free soundscape modelling ... everyone who hears "B" (as identified subtly or overtly as "B") ... will think it sounds better. IF they understand all those words-of-art.
Anyway... there are probably more biases, but these suffice to amuse the zoo keepers.
GoatGuy
1: aggrandizement - money spent on expensive stuff, which, when placed into service delivers the pablum (placebo) effect, with the buyer (especially) and her horde falling into line. "Transients much more detailed, and bass is incredibly more open and transparent on the broad soundstage. The speakers utterly disappeared, etc..."
2: different = better = different - well, this is easy. ANY difference except for the most egregious adding-of-noise (and then, incredibly, even then, for some listeners) is viewed as better. Glacial-speed "knob twiddling" through making basically irreversible system changes. One can't ungrind the edge of a cd, easily.
3: amplitude bias - maybe the most common of all! When "B" is put into service, virtually all operators/listeners will "turn up the volume a bit" in order to detect what supposedly is the improvement. Well, we've got deep psychological bias that in general, unless painful, a bit louder = a bit better. Try it with a friend sometime! Play a CD at volume setting 5 (say). Take the CD out, make a show of putting another one (but really the first one) back in, and set the volume to 5.5 ... just a wee bit louder. The friend will almost inevitably say it is way better.
4: completion bias - now, without changing the volume, do the same thing with a different CD. Play a part of a track. DON'T let the track finish! Take the CD out, make a show of getting a duplicate (somehow magic-unicorn-dust improved, but actually the exact same CD), and inserting it. Find the same track ... and play it again. This time, let the track finish. Blam... 99% of listeners will comment favorably about "B". They don't understand their inner feeling of being more satisfied when the passage is allowed to complete, and mistake such better feelings for better sound. Ah... we monkeys.
5: repetition bias - EVEN if one lets both passage "A" and "B" complete, for music that is exciting, harmonic and edgy, generally people much prefer the 2nd playback. Same deal, "make a show of it" exchanging (but not) the CD. Psychologists found that 5 out of 7 people (1970s) prefer the 2nd repetition over the first. With all knobs exactly untouched! Oh well...
6: Academic Bias - when the experimenter is responsible for making an "informed decision", involving technological words-of-art, diagrams and so on. We audiophiles are especially subject to this poor canard: Even though secretly there may be a straight wire going from input to output of a preamplifier (as an example), so long as there's a big write up of cascodes, and balanced current sources, and Sziklai complimentary signal path active devices, and capacitor (or whatever bogey) free soundscape modelling ... everyone who hears "B" (as identified subtly or overtly as "B") ... will think it sounds better. IF they understand all those words-of-art.
Anyway... there are probably more biases, but these suffice to amuse the zoo keepers.
GoatGuy
I really held back there.
People who know how a CD player works realises that a few missed pits or misread pits are the routine parcel of the error correction. A few dozen consecutive errors? - no sweat, corrected to perfection. A few 100? No sweat.
Many 1000's of misread pits? Yes, that becomes problematic. Now we are starting to hear the decoder fill in missed parts by repeating sections from previous reads - sort of like a DJ repeating sections. Not subtle, very obvious for anyone.
Back to the CD lathe. Does anyone realise how much intelligence and machine power it would require not only to change the (mis)reading of pits, but in such a way that it alters the reconstructed waveform in such a way that transients are reproduced stronger? You must know which pits actually are part of the high frequency signal content, and then alter them in such a way that the error correction system is fooled, AND also in such a way that the result is 'better'?
Really.
jan
People who know how a CD player works realises that a few missed pits or misread pits are the routine parcel of the error correction. A few dozen consecutive errors? - no sweat, corrected to perfection. A few 100? No sweat.
Many 1000's of misread pits? Yes, that becomes problematic. Now we are starting to hear the decoder fill in missed parts by repeating sections from previous reads - sort of like a DJ repeating sections. Not subtle, very obvious for anyone.
Back to the CD lathe. Does anyone realise how much intelligence and machine power it would require not only to change the (mis)reading of pits, but in such a way that it alters the reconstructed waveform in such a way that transients are reproduced stronger? You must know which pits actually are part of the high frequency signal content, and then alter them in such a way that the error correction system is fooled, AND also in such a way that the result is 'better'?
Really.
jan
IMO GoatGuy hits on the biggest flaw in all this sort of thing. Basically you can't play a tune twice and compare it. Audio memory isn't good enough and it's also affected by what was last heard. Audio memory, for me anyway, has a memory. The end of the tune affects how I hear the beginning on the second play.
Ok, here's a question. I have no idea what the answer is.
In the case of a zero error correction read back (idealized of course), the Reed-Solomon code is reconstructed without any additional processing.
In the case of a worst-case error correction, the Read-Solomon code is reconstructed, perhaps (and I don't KNOW if this is done) with processing and interpolation (up to a point). Now I am NOT getting at the shape of the reconstructed waveform.
The question that arises is the nature of the processing and the time required to achieve that vs. the outputting of data to the DAC chip itself. What I am thinking about is the effect of inserting a shorter and longer sequence into the processing stream to retrieve the corrected waveform, and IF that might in effect create a result akin to "jitter".
_-_-
In the case of a zero error correction read back (idealized of course), the Reed-Solomon code is reconstructed without any additional processing.
In the case of a worst-case error correction, the Read-Solomon code is reconstructed, perhaps (and I don't KNOW if this is done) with processing and interpolation (up to a point). Now I am NOT getting at the shape of the reconstructed waveform.
The question that arises is the nature of the processing and the time required to achieve that vs. the outputting of data to the DAC chip itself. What I am thinking about is the effect of inserting a shorter and longer sequence into the processing stream to retrieve the corrected waveform, and IF that might in effect create a result akin to "jitter".
_-_-
In the early days of CD freezing the disc was a very popular tweaking method. Also the use of a "sandwich" of two discs (gave a "audible reduction of jitter").
Regarding expensive CD players, I had a very enlightening experience with a Accuphase player (priced over 20000$ at that time): it's tracking abilities were way below of a 300$ Philips. Tested with a real-life test disc. (Sputtered some acrylic glue un a disc while spinning in a player. It happend accidentally.)
Regarding expensive CD players, I had a very enlightening experience with a Accuphase player (priced over 20000$ at that time): it's tracking abilities were way below of a 300$ Philips. Tested with a real-life test disc. (Sputtered some acrylic glue un a disc while spinning in a player. It happend accidentally.)
The way I understand it is that the error correction is transparant in that it is always active, just selects different parts of the data stream to construct the words and frames to send to the DAC.
Error concealment is not, but it is such a last ditch operation that your timing is the least of your worries. You can have seconds worth of sound bites being followed by the same ones because you miss whole chunks of data. As I said, that is something you will not miss - it sounds like a broken record (which, quite literally, it is).
I believe (not sure) that in some players the concealment just mutes the output for the missing data period - which will be pretty obvious as well.
Elektor had a kit for an error counter once - there's a pin in the CD player that signals everytime the error correction selects redundant data. A friend used it on his player and was aghast when he easily saw 4,000 to 8,000 errors during a single CD play. All perfectly corrected, of course.
jan
Last edited:
Yes, that is my understanding. Essentially you feed in a set of bits read from the disc and you get out a different set of bits which are correct audio data. At this stage in the proceedings timing is not an issue as it is simply data handling. There is also data interleaving to undo, but I can't remember whether this comes before or after the decoding.jan.didden said:
People making these 'tweak' claims merely damage their own credibility.
Turns out that the ECC of the compact disk is like an onion: multiple layers to address different run-lengths of error-condition. EFM modulation covers 588 bit channel-frames, CIRC covers 588 sample sectors, subchannel encoding can contain spectrum-hints for lost-data reconstruction.
Reed Solomon encoding (CIRC) handles linear runs of bad data from scratches both radial and tangential. The EFW encoding handles much smaller data issues caused by specks, dusts, hairline scratches, errors in media (no recording is perfect!), gradual aging.
As others have pointed out ... for a recording to have its spectral signature "improved" ... is quite a claim. The mere reconstruction of missing channel frames could, conceivably give better and more accurate fine-structure response, but it certainly shouldn't be perceived either as "better bass" or "faster transient response". Those concepts are so much longer than the channel time window that they're unrelated.
I remain convinced that most people are subject to the 6 audiophile self-delusion factors.
GoatGuy
Reed Solomon encoding (CIRC) handles linear runs of bad data from scratches both radial and tangential. The EFW encoding handles much smaller data issues caused by specks, dusts, hairline scratches, errors in media (no recording is perfect!), gradual aging.
As others have pointed out ... for a recording to have its spectral signature "improved" ... is quite a claim. The mere reconstruction of missing channel frames could, conceivably give better and more accurate fine-structure response, but it certainly shouldn't be perceived either as "better bass" or "faster transient response". Those concepts are so much longer than the channel time window that they're unrelated.
I remain convinced that most people are subject to the 6 audiophile self-delusion factors.
GoatGuy
Most? There are no absolutes but I'd say all. I can convince myself of many things. If I really put my mind to it, I can hear obvious differences between identical signals if I just keep telling myself they're there and suppress the science side of the brain.
Agee -we ALL are humans with the same general mental makeup. All those attributes that sometimes we rather wouldn't have, have been selected over the eons by Mother Nature because it improves our survival.
Knowing the issues doesn't mean your immune to it, far from it! The only thing you can hope for is that the knowledge helps you to do slightly better than otherwise.
jan
Cognitive bias. All fun stuff. Another interesting thing is that if you tell people what they should hear, they often will hear those things.
Michael Shermer's TED talk provides an entertaining look at cognitive bias...
Michael Shermer: Why people believe weird things | Video on TED.com
~Tom
Michael Shermer's TED talk provides an entertaining look at cognitive bias...
Michael Shermer: Why people believe weird things | Video on TED.com
~Tom
Try looking at it a different way.
Maybe it has nothing to with data error and everything to do with the physical effects of having a better balanced cd spinning at speed and less interaction with the servo electronics and hence less noise in the circuits.
I had a few discs lathed by a friend several years ago, it made no difference of all of them except the Trinity Sessions by the Cowboy Junkies- where the difference was profound. I can only assume it does something to balance the rotation of cd's where the center hole is not cut centrally to the to the edge of the disc.
I wouldn't pay money for one, but i cannot deny that it did make a difference in open instance
Maybe it has nothing to with data error and everything to do with the physical effects of having a better balanced cd spinning at speed and less interaction with the servo electronics and hence less noise in the circuits.
I had a few discs lathed by a friend several years ago, it made no difference of all of them except the Trinity Sessions by the Cowboy Junkies- where the difference was profound. I can only assume it does something to balance the rotation of cd's where the center hole is not cut centrally to the to the edge of the disc.
I wouldn't pay money for one, but i cannot deny that it did make a difference in open instance
The thing is I was the one who was saying it would make no difference. I didn't fork out any money to buy one of these devices to justify my purchase, a friend cut them for nothing. So there is no bias towards paying for results...
Found a similar discussion on playback of files from different media sources, i.e. SSD, HDD, USB which make similar claims.
I have actually decided to test a theory and have decided to make myself a media centre.
Found a similar discussion on playback of files from different media sources, i.e. SSD, HDD, USB which make similar claims.
I have actually decided to test a theory and have decided to make myself a media centre.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.