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[#41] Blogs: 數碼音樂重播專欄 (1) Yes Hercules I take your point. The crux of the matter is whether the data filtered out represent utter silence that is totally useless (over 7 GB in the case of a 2L album) or therein are overtones and harmonics that enrich the fundamentals and harmonics within the 20 to 20 KHz hearing limit. Well I belong to the camp accepting the enrichment concept. New equipment, for example, both the Wadia S-7i CD player and McIntosh preamps incorporate up conversion processes on the incoming CD format of 16/44.1. Therefore audiophiles have to decide for themselves whether these are merely marketing gimmicks or they actually will bring about improvements in sound. 最後修改時間: 2011-05-02 14:46:47 |
momei![]() 203.xxx.xxx.61 |
2011-05-02 14:37 | |
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[#42] Blogs: 數碼音樂重播專欄 (1) in video u will view all black or all white using 576i format data the same as 1080p format data, irrespective there is upconvert of 576i to 1080p. however when there are motions and multi colour images it is a different story. most people can see true 1080p better than upscaled 578i to 1080p. why is it so hard to hear similarly in audio with upsampling of 16/44 format to hi rez to approximate true hi rez? |
cpu8088![]() 115.xxx.xxx.214 |
2011-05-02 15:02 |
[#43] Blogs: 數碼音樂重播專欄 (1) quoted from BobKatz (great recording engineer) Mastering audio the art and the sciencethe ultimate listening test: is it the filtering or the bandwidth? in December 1996, I sought to systematically find reasons for sonic differences between sample rates, performing a listening test. with the collaboration of members of the Pro Audio maillist. The question we wanted to answer was. Does high sample rate audio sound better ( or different ) because of increased bandwidth, or because of less-instructive filtering? we developed a test that would eliminate all variables except bandwidth. Other major factors were held constant, sample rate, filter design, DAC. and Jitter. The test were devised was to take a 96khz recording, and compare the effect on it of 2 different low pass filters. The volunteer design team consisted of Ernst parth (filter code), matthew xavier moral (shell), rusty scott (filter design), and bob katz (coordinator and beta tester). We created a digital audio filtering program with two impeccably-designed filters which are mathematically identical, except that one cuts off at 20khz. the filters were designed for overkill, with exemplary characteristics : double precison diethered, FIR linear phase, 255-tap, > 110dB stopband attenuation, and < .01dB passband ripple. Fort the first listening test, I took a 96khz orchestral recording, filtered it and laid both versions into sonic solutions DAW for comparison. I expected to hear radical differences between the 20khz and 40khz filtered material. BUT I COULD NOT HEAR ANY DIFFERENT! Next, I compared the 20khz filtered against "no filter" (of course , the material has already pass through two 48khz filters in the converters) Again I could not hear any difference! The intention was to listen double blind ; but EVEN sighted, 10 additional listeners who took part in the tests (one at a time) heard no difference between the 20khz digital filter and no filter. And if no one can hear a difference sighted, why proceed to a blind test? I then tried different types of musical material, including a close-milked recording of castanets ( which have considerable ultrasonic information). but there was still no audible difference. I then created a test which put 20khz filtered material into one channel of my Stax electrostatic headphones and the time- aligned wide bandwidth material into the other channel. I was not able to detect any image shift-there was always a perfect mono center at all frequencies in the headphones! This must be a pretty darn good filter! As a last resort, I went back to the list and asked maillist participant robert bristow johnston to design a special Dirty filters with 0.5dB ripple in the passband. Finally, with this filter, I was able to hear a difference... it added a boxy, veiled, " gritty" quality that resembles the sound of some of the cheaper cd players we all know. After I conducted my test, several others have tried this filtering program, and most have reached the same conclusion: the filter is inaudible. one maillist participant, eelco grimm, a netherlands based writer and engineer, performed the test and reported no audible differences using a sonic solutions system, yet he and a colleague passed a blind test between filtered and non filtered using an augan workstation. He did not compare the sound of the 20khz versus 40khz filters, so we are not sure if he was hearing the filter or the bandwidth ( i suspect the filter). We are not certain, but perhaps the reason eelco uniquely reported a sonic difference is that the sonic system produced sufficient jitter to mask the other differences, which must be very subtle indeed! ! Be aware that two other 48khz filters in the chain may have obscured the audible effect of the test filter, so it is very difficult to design a perfect test. this 1996 test seems to show that a " perfect 20khz filter" can be designed. regardless of whether eelco s group did reliably hear bandwidth differences, it should be clear by now that differences people hear between sample rates more likely due to filter design than to supersonic bandwidth. Ironically, it was necessary to make a high sample rate recording in order to prove that high sample rates may not be necessary |
batmanames04![]() 61.xxx.xxx.217 |
2011-05-02 19:54 |
[#44] Blogs: 數碼音樂重播專欄 (1) My DIY DAC hear almost no different between 16 44.1 and 24/96 material if they are derived from the same source |
batmanames04![]() 61.xxx.xxx.217 |
2011-05-02 20:02 |
[#45] Blogs: 數碼音樂重播專欄 (1) if you believe nyquist theorm, a good dac should hear no big different bewteen 16 44.1 and 24 96 material ( provide they are from the same source) ![]() |
batmanames04![]() 61.xxx.xxx.217 |
2011-05-02 20:16 |
[#46] Blogs: 數碼音樂重播專欄 (1) 1996 thats 15 years ago. there was no diamond beryllium or other tweeters with exotic materials. could those old tweeters output properly the frequencies above 20khz? how good was the room treatments for the tests? if it was one that absorbed a lot of high frequencies of course there was less chance to hear properly. |
cpu8088![]() 115.xxx.xxx.214 |
2011-05-02 21:10 |
[#47] Blogs: 數碼音樂重播專欄 (1) """a good dac should hear no big different bewteen 16 44.1 and 24 96 material""" i must be wrong. how can a dac hear things? i thought human can hear but a dac? |
cpu8088![]() 115.xxx.xxx.214 |
2011-05-02 21:11 |
[#48] Blogs: 數碼音樂重播專欄 (1) from wiki: Theorems have two components, called the hypotheses and the conclusions. The proof of a mathematical theorem is a logical argument demonstrating that the conclusions are a necessary consequence of the hypotheses, in the sense that if the hypotheses are true then the conclusions must also be true, without any further assumptions. The concept of a theorem is therefore fundamentally deductive, in contrast to the notion of a scientific theory, which is empirical. |
cpu8088![]() 115.xxx.xxx.214 |
2011-05-02 21:32 |
[#49] Blogs: 數碼音樂重播專欄 (1) Batmanames04, Merely to mention the view of Bill Schnee to balance that of Bob Katz who is associated with Daniel Weiss. Bill advocates 24/192. In my book I have heard and read about Bill Schnee more than Bob Katz though I do not know in reality who is more famous. Anyway, back to the subject matter. If you use a PC and Foobar 2000 or WASAPI, then I get stuck because I have never used them. If you use MAC and iTunes then follow test 1 below. Test 1: You need to open MIDI, play a track of 24/96 and check whether you have set your computer to recognize you DIY DAC and also whether the setting displays 24/96 and not 16/44.1 whilst you play the 24/96 track. If the recognition and setting remains at 16/44.1, then it means you have always played your 24/96 tracks at 16/44.1, thus you heard no difference. If you have already done this previously and the recognition and setting is correct, please come back for test 2. |
momei![]() 203.xxx.xxx.61 |
2011-05-02 22:25 |
[#50] Blogs: 數碼音樂重播專欄 (1) try to audition a high end DAC, your ears can hardly distinguish 16 44.1 and 24 96 recordings |
batmanames04![]() 61.xxx.xxx.217 |
2011-05-02 22:26 |
[#51] Blogs: 數碼音樂重播專欄 (1) momei I am using PC with foobar kernel streaming mode and the screen showing sampling rates16 44.1 and 24 96. |
batmanames04![]() 61.xxx.xxx.217 |
2011-05-02 22:31 |
[#52] Blogs: 數碼音樂重播專欄 (1) If the file is playback from computer then the sound quality maybe affected by the quality of the computer. I think that it is better to record the same sound with original file in 16bit/44.1Khz and 24bit/96khz into a CD then play it by a CDP. |
DYreal![]() 113.xxx.xxx.158 |
2011-05-02 22:36 |
[#53] Blogs: 數碼音樂重播專欄 (1) then it will be comparing cdp vs pc, not a good control experiment may be you can use pioneer dv ax 10 universal player output 16/44.1 and 24/96 for comparison |
batmanames04![]() 61.xxx.xxx.217 |
2011-05-02 22:49 |
[#54] Blogs: 數碼音樂重播專欄 (1) CPU8088, Regarding beryllium tweeters: not intending to challenge you but merely to tell you the fact. In the 70's Yamaha already made beryllium tweeter for its NS1000 loudspeakers. They were available in Hong Kong and some audiophiles bought them. The Yamaha tweeters are distinguishable from that of current Focal ones in that the Y ones are convex whereas the F ones are concave. I have read posts here about your undue favour towards Focal speakers. Could you tell us what process Focal uses to make the tweeters? Vapour deposition or what? Apparently the Focal tweeters are thinner than the Yamaha ones. I do not have information what process Yamaha used and I guess it might be heat formation, that is, putting the metal powder in a mould and heat it to the melting temperature in an oven. Talking about Focal Utopia, I suspect, based on what I deduced from listening, the tweeter has dispersion restrictions merely because of the design of the tweeter cabinet that has the width and depth the same as the woofer cabinet. Other designs such as the Karma Exquisite, the KEF Fat Lady all have the tweeter housing tapered to the smallest size to help dispersion. Or in the B&W and Tannoy Royal designs, place it on top. |
momei![]() 203.xxx.xxx.61 |
2011-05-02 23:01 |
[#55] Blogs: 數碼音樂重播專欄 (1) this thread is about digital music not tweeters anyway yamaha of the old was using beryllium vapour deposit not pure beryllium what focal is doing. the diamonds of b and w and kharma are vapour deposits with diamond flakes bond together. dispersion pattern, baffle and cabinet designs are different subjects. what i questioned was what speakers used in 1996 for the test to output over 20khz? |
cpu8088![]() 115.xxx.xxx.214 |
2011-05-03 09:53 |
[#56] Blogs: 數碼音樂重播專欄 (1) but most 33 members know you like jm lab beryillium tweeter |
batmanames04![]() 180.xxx.xxx.233 |
2011-05-03 10:47 |
[#57] Blogs: 數碼音樂重播專欄 (1) a CD contains 16 bit samples with a 44.1 kHz sample rate. this allows theoretically for a dynamic range of 16*6= -96 dBFS and 44.1/2 = 22.05 kHz as the highest possible frequency. recordings are often made with a greater bit depth (24) and a higher sample rate. one of the benefits of computer based audio is that you are not in need of recordings down sampled to CD format. uou can play the original recording at its original bit depth and sample rate (if your sound card allows for it). a 24/96 recording allows for a dynamic range of 24*6= -144 dBFS. this sounds impressive but CD’s -96 dBFS is very soft and the noise floor of your gear e.g. -110 dBFS will be the limiting factor. probably listening to the decay of instruments might reveal a subtle difference. 96 kHz has a Nyquist frequency of 48 kHz. Sounds impressive too but our hearing may stop somewhere at 20 kHz (when we are young). there are reasons why a hi-rez recording will sound different. 1) Down sampling might introduce artifacts. 2)our tweeters can sound different when modulated with signals 20 kHz. often no audible differences between CD audio and higher resolutions are reported on the internet. similarly some claim no audible differences between CD audio and high bitrate MP3. as 1+1=2 some conclude that there isn’t a difference between MP3 and Hi-rez audio! |
cpu8088![]() 115.xxx.xxx.214 |
2011-05-03 10:52 |
[#58] Blogs: 數碼音樂重播專欄 (1) 2)our tweeters can sound different when modulated with signals 20 kHz. ???? |
batmanames04![]() 180.xxx.xxx.251 |
2011-05-03 13:04 |
[#59] Blogs: 數碼音樂重播專欄 (1) similarly some claim no audible differences between CD audio and high bitrate MP3 ??? (can mp3 reach 20khz bandwidth |
batmanames04![]() 180.xxx.xxx.251 |
2011-05-03 13:05 |
[#60] Blogs: 數碼音樂重播專欄 (1) Batmanames04, It seems better for me to know a bit more about your DIY DAC and the tracks you used by which you found no difference than to ask you to go straight into Test 2. Does your DAC support 24/192 or even DXD? Does your computer out port support 24/192 and what interface or connector you use to play those tracks? The port and interface could be bottle necks and is 24/192 shown on the monitor screen to confirm such resolution is being played? I am trying to see whether by listening to 24/192 you may be able to hear the difference. Also please list two to three tracks you used previously, the source and the genre (type of music). I forgot where I read about the story. Morten Lindberg (proprietor of the 2L label in Norway) took some of his tracks to the US to meet up with equipment manufacturers and importers and played them two different resolutions. At the end they all preferred the higher resolution version and took copies of those. 最後修改時間: 2011-05-03 13:34:28 |
momei![]() 203.xxx.xxx.61 |
2011-05-03 13:33 |