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#41
Posted to rec.audio.high-end
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Can mp3 quality be improved?
On Thu, 15 Dec 2011 00:37:27 +0000, Arny Krueger wrote:
"Audio Empire" wrote in message ... On Mon, 12 Dec 2011 16:07:13 -0800, Arny Krueger wrote (in article ): "Chuck Finley" wrote in message ... I bought an Escient music server several years ago when hard drive space was still relatively expensive. Most of my music on there is encoded at 320 and 192. Shouldn't be a problem. Reviews of DACs typically discuss how they can improve the sound of CD quality or hi-rez music, Generally, false claims. Audiophile myths. Dreams, not actualities. Blatantly false sales pitches. The results of sighted evaluations. Not exactly true. While I agree that most DACs that are constructed using IC converters sound so much alike that the differences (if any) are trivial, high-end DACs using discrete, proprietary circuitry not only can sound better than the mass-produced IC chip-based DACs, but they sound significantly different from one another. Reliable proof? The skeptical members of this forum should form a consortium to offer a signficiant cash reward for reliable proof. After all, it worked for the Great James Randi! You did? if you see him again say Hi to him, I love that man :-) Edmund |
#42
Posted to rec.audio.high-end
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Can mp3 quality be improved?
Edmund wrote:
At the time when Compression meant exactly that,: "compressing" and some sneaky developers "sold" there reduction scheme as "compression" and with that, they introduced a misleading and plain wrong term. When was that time, though? In 1984 Terry Welch wrote in his classic paper: "The data compression described by this model is a reversible process that is different from other forms of 'data compression' ..... in which data is deleted according to some relevance criterion." So it's clear that "lossy compression" was familiar at that time. At the time the claim was made it was inaudible, inaudible by who and played on what? What claim was that? The people who designed perceptual coders did a lot of blind testing, and in _Subjective Evaluation of State-of-the-Art 2-Channel Audio Codecs_ (1999) its audibility was studied in considerable detail. Andrew. |
#43
Posted to rec.audio.high-end
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Can mp3 quality be improved?
On Thu, 15 Dec 2011 04:03:00 -0800, Mr. Finsky wrote
(in article ): On Dec 14, 6:37=A0pm, "Arny Krueger" wrote: "Audio Empire" wrote in message ... Reliable proof? The skeptical members of this forum should form a consortium to offer a signficiant cash reward for reliable proof. After all, it worked for the Great James Randi! AFAIK, no cable snake oil artist or reviewer has ever even tried to collect the million dollars. I do recall reading that various audiophile writers have attempted to test the Great James Randi and collect the million smackers. The problem is that Randi avoided all contact with anyone trying to do a test. Randi is wonderful about publicity but appears to avoid a confrontation that might cost him money or demonstrate that he may be as big a phony as his "magician" targets. Personally, I know I can hear the difference between mass market junk and "audiophile" gear. I do think that the law of diminishing returns exists in the audiophile world. The improvements obtained by spending more money become small, once you have reached a certain price point. Unfortunately, when much of this stuff is subjected to a so-called "bias-controlled" test (like a DBT or ABX test) in a lot of cases, these differences disappear. In other words, the guy who, an hour ago, swore that he could hear the difference between mass-market junk and "audiophile" gear, couldn't tell which was which once he could no longer see what it was that he was listening to in a DBT or ABX test. I know that this is fact in cables. Cheap, throw-away RCA interconnects, for instance, sound no different from an expensive multi-hundred (or even multi-thousand) dollar interconnect in a double-blind test AND, they even measure EXACTLY the same. But people still insist that they can hear the difference and the expensive cables always sound better than the cheap ones! However once subjected to a DBT, suddenly these cables sound exactly the same. Recently I've been involved with group of other recording engineers and recording enthusiasts in DBTs of DACs, What we have found is that essentially all DACs built using IC D-to-A converters sound so much alike that in a blind test, nobody could tell (most of the time) that the people conducting the tests had switched from one converter to another! What we found was that a $300 Musical Fidelity V-DAC sounded identical to a $1000 Benchmark DAC1, and that the Benchmark sounded identical to a $1400 Antelope Zodiac +! Later we contrasted the Antelope Zodiac + with a $6000 Weiss DAC202, and could not tell the difference between them in any statistically significant way, either. When we contrasted these IC-based DACs against cost-is-no-object discrete component designs from MSB and dCS, for instance, we found it quite trivial to tell the difference between the two expensive DACs and their cheaper IC-based competition. Those who post here and believe that everything sounds the same because electronics for audio is a "mature technology" discredit this notion by stating that IC-based DACs HAVE to better than discrete component units because it's easier to control the variables in an integrated circuit design than it is to control them in a design built-up of discrete components. They also say that the IC DACs are transparent, and that this has been proven because some testers have daisy-chained DACs and ADCs together and compared the results with only one conversion, this proving that modern DACs add nothing to the sound. What I have found is that IC-based DACs do is to homogenize the audio and then preserve that homogenization through repeated conversions. I say that because, compared to the dCS Debussy and the MSB DAC-IV, that's what IC-based DACs all sound like - homogenized! Now with amps, some sound better than others. I have a pair of Behringer A-500 power amps. They're cheap ($200 for about 160 Watts/channel) and they sound fine....... until you A/B them against a Krell S-300i! (150 Watts/Channel) then, even in a DBT, the Krell shows what it is made of. It sounds much cleaner, much more musical with better dynamic contrasts, and better sound-staging. Many of these improvements aren't immediately apparent, and some only show-up with certain kinds of program material and certain signal conditions, but they ARE there and do show-up in DBTs. In fact there are certain circumstances where ALL amplifiers sound different from one another, even similar amps. This comes down to things like power supply design, but these differences do exist, and usually the audiophile gear outperforms the cheap, mass market gear, even if they have similar specs (the everything-sounds-the-same crowd is going howl at this statement!). I examined and tested the difference between 192 .wma files and a aiff files ripped through iTunes. The difference was quite minor. However, the cost of hard drives is so low that saving space is not worth the potential problems. Besides, ripping CD's through dbpoweramp to FLAC is loads of fun and flexibility. FLAC and Apple Lossless both seem pretty flawless. |
#44
Posted to rec.audio.high-end
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Can mp3 quality be improved?
"Audio Empire" wrote in message
... Unfortunately, when much of this stuff is subjected to a so-called "bias-controlled" test (like a DBT or ABX test) in a lot of cases, these differences disappear. Why would that be unfortunate? In other words, the guy who, an hour ago, swore that he could hear the difference between mass-market junk and "audiophile" gear, couldn't tell which was which once he could no longer see what it was that he was listening to in a DBT or ABX test. I've certainly seen that happen, a great many times. It first happened to me after I built the first ABX box and did the first ABX test. I then saw it happen to an ever-widening group of people. First close friends, and then casual acquaintances, and ultimately people I never knew. I know that this is fact in cables. It is a fact for an ever-increasingly large circle of equipment. However, it will *never* be true for LP playback and analog tape. Cheap, throw-away RCA interconnects, for instance, sound no different from an expensive multi-hundred (or even multi-thousand) dollar interconnect in a double-blind test AND, they even measure EXACTLY the same. Pretty much. I have measured subtle differences among interconnects. Different interconnects of reasonable lengths also have small but clearly measurable effects on some of the equipment that they are used with. I can reliably measure these differences using test equipment based on the single-chip mainstream ADCs and DACs that are commonly used these days. But people still insist that they can hear the difference and the expensive cables always sound better than the cheap ones! However once subjected to a DBT, suddenly these cables sound exactly the same. No surprise. And, now that we have ADCs, DACs and other components that have fewer measurable differences among them and as compared to the technical ideal, than exist among some interconnects as they are commonly used... Surprised? BTW, these ADCs and DACs that perform technically better than some interconnects as the interconnects are used, are all mainstream single-chip devices, or even single chips with a goodly number of both ADCs and DACs on the same chip. I see no reliable evidence that *anybody* can reliably discern audible differences among ADCs and DACs with better than +/- 0.1 dB response in the usual audio band, that also have all spurious responses 100 dB or more down. I hear occasional anecdotes, but they are so incomplete and vague as to be IMO completely irrelevant to any reasonable discussion. Please prove me wrong! |
#45
Posted to rec.audio.high-end
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Can mp3 quality be improved?
Audio Empire wrote:
Those cheap IC-based DAC chips MIGHT be sonically transparent to the Hoi-Polloi, but they sure don't sound as good, or image as well as a good, discrete component DAC such as those used in the MSB DACIV or the dCS Debussy. This has been noted in DBTs against a number of other DACs using IC-based Burr-Brown (TI), AMD and ESS DAC chips from manufacturers such as Benchmark, Antelope, Musical Fidelity, Music Streamer, Cambridge and Weiss, to name a few and the differences can be measured and easily seen. Look at the 1/3-octave spectrum-with-noise data, or the Intermodulation spectrum plots or the high-resolution jitter spectrum data and contrast the results of the IC-based DACs with those from some of these discrete component units such as the MSB and dCS units mentioned above. Their superiority is as easy to see as it is to hear. I suspect that the DBTs that show all modern DACs to be more-or-less equally transparent were comparing DACs using the more popular mass-produced integrated circuit DAC chips. Like I said in another post, only the ESS 32-bit "SabreDAC" has any real edge here, either sonically or by measurement, and it still doesn't sound or measure as good as the MSB proprietary "Ladder DAC" or the dCS "Ring DAC". OK, where are those measurements of dCD or MSB devices? And how about repeatability of those measurements? This type of "everything sounds the same" argument certainly makes audio cheaper. If everything sounds the same, then there's no reason to buy anything expensive. A $50 CD player sounds exactly like a multiple thousand dollar unit so all one needs to buy is the $50 player. All amplifiers sound exactly alike, so why buy a Krell integrated for $3000 when a $150 TEAC receiver from Costco performs exactly like it? It's tempting to believe this. Too bad that neither of these money-saving assumptions is true..... Take heart, though. A $5 Radio-Shack interconnect DOES sound exactly like a $4000 pair of Nordost Valhallahs and a hank of 14-gauge lamp cord does perform identically to a speaker cable from Oracle costing many hundreds of dollars per foot. Also, the IC processes keep improving and chips like the SabreDAC are closing-in on the cost-is-no-object designs, so there is hope for us financial mortals after all! Sorry, but measurements of speaker wires differ much more than measurements of decent DACs (if those DACs are considered neutral and have measurements considered good). As I wrote before -- those things do not add up. Decent DACs are esiencially neutral down to -100dB or better (noise, thd, nonlinearities, intermodulation, channel separation, etc). that is down to 0.001% -- all that in range from 1 to 40000Hz. Virtually no speaker wire is as flat (due to low - just few Ohms, impdenace of load, even 0.1 Ohm wire impedance translates to much greater distortions). Thus, my questions: where are the measurements of this discrete component DACs? How they were made and by whom... rgds \SK -- "Never underestimate the power of human stupidity" -- L. Lang -- http://www.tajga.org -- (some photos from my travels) |
#46
Posted to rec.audio.high-end
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Can mp3 quality be improved?
On Sun, 18 Dec 2011 06:37:06 -0800, ScottW wrote
(in article ): On Dec 15, 7:58=A0pm, Audio Empire wrote: On Thu, 15 Dec 2011 04:03:00 -0800, Mr. Finsky wrote (in article ): On Dec 14, 6:37=3DA0pm, "Arny Krueger" wrote: Reliable proof? The skeptical members of this forum should form a consortium to offer a signficiant cash reward for reliable proof. After all, it worked for the Great James Randi! AFAIK, no cable snake oil artist or reviewer has ever even tried to collect the million dollars. I do recall reading that various audiophile writers have attempted to test the Great James Randi and collect the million smackers. The problem is that Randi avoided all contact with anyone trying to do a test. Randi is wonderful about publicity but appears to avoid a confrontation that might cost him money or demonstrate that he may be as big a phony as his "magician" targets. Personally, I know I can hear the difference between mass market junk and "audiophile" gear. I do think that the law of diminishing returns exists in the audiophile world. The improvements obtained by spending more money become small, once you have reached a certain price point. Unfortunately, when much of this stuff is subjected to a so-called "bias-controlled" test (like a DBT or ABX test) in a lot of cases, these differences disappear. In other words, the guy who, an hour ago, swore that he could hear the difference between mass-market junk and "audiophile" gear, couldn't tell which was which once he could no longer see what it was that he was listening to in a DBT or ABX test. I know that this is fact in cables. Cheap, throw-away RCA interconnects, for instance, sound no different from an expensive multi-hundred (or even multi-thousand) dollar interconnect in a double-blind test AND, they even measure EXACTLY the same. But people still insist that they can hear the difference and the expensive cables always sound better than the cheap ones! However once subjected to a DBT, suddenly these cables sound exactly the same. Except in single ended systems. Some cheap interconnects have such a high resistance on the ground/return that system noise is elevated. No need for an interconnect to be expensive to deal with this but some of the stock cheap stuff is simply too poorly made. Jensen has a couple of excellent articles that touch on the subject. This is just one. http://www.jensen-transformers.com/a...%20seminar.pdf ScottW I've never run across any interconnects like the ones you mention and the ones Mr. Whitlock mentions in his paper, but they could exist, I guess. He is, however, very correct when he says that the advertising hype about "transmission-line theory" often used by cable manufacturers to justify their high-prices, is a lot of hooey and that at audio frequencies, transmission-line effects don't come into play until the average audio interconnect is more than FOUR THOUSAND feet long! There are a number of things that the average audio enthusiast and measure quite inexpensively if he so wishes. One can go on E-bay and buy a used function generator for just a few bucks, likewise a used oscilloscope with a 6 MHz bandwidth can be had very cheaply as well. With these two instruments (and some cable adaptors) it is possible to test some of these cable claims quite thoroughly. With the o'scope and the signal generator set to sine wave, it is possible to test the cable's bandwidth and its frequency response. This will tell you if the manufacturer is "cheating" by putting outside components on his cables to alter their frequency response and therefore cause them to sound "different" from their competition. You can also check their bandwidth. I've never measured any audio interconnect of a meter or less that wasn't dead flat from DC to at least 1 MHz! Next, using the function generator switched to "square wave" output and the oscilloscope again, it is possible to look at a cables' square-wave response at 10 Hz or 1 MHz, and anything in between. No interconnect that I've tested has shown anything but a perfect square wave at any frequency up to one MHz, which is plenty for any audio component. Square wave shape shows bandwidth limitation, excess capacitance and inductance, as well as distortion and induced noise. It doesn't take many such tests of high-end vs cheap cables to see that there is no measureable difference between any of them. |
#47
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