David Morgan (MAMS) wrote:> "Jerry Avins" <jya@ieee.org> wrote in message... > >> You can reach the limits of audible frequencies at sampling rates far >> below 96 KHz. You can exceed the accuracy of tape or vinyl with numbers >> smaller that 32 bits. > > 16 bit, 44.1khz is more than adequate for accurate reproduction within > the range of human hearing... that's why it was chosen 20 years ago > and that is why it is still the standard digital audio delivery medium today. > > If anything, the 'bar' of acceptable quality is being progressively and > willingly lowered by MP3, ATRAC and the ongoing host of other data > compression codecs and schemes.Sure. There are good arguments to be made for more than 16 bits in places along the processing chain, but 16 bits dithered down from the processing word width is plenty for reproduction. (You say you can hear that 17 bits sounds better? Listen in good health!) The anti-alias and reconstruction filters are easier to build (fewer compromises needed) at the somewhat higher sample rate of 48 KHz, but that's not the issue. (Especially for me, with my 4 KHz cutoff. :-( ) I try to avoid numbers in threads like this because they often lead to unproductive digressions. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Help understanding audio sampling
Started by ●April 14, 2007
Reply by ●April 16, 20072007-04-16
Reply by ●April 16, 20072007-04-16
David Morgan (MAMS) wrote:> "Jerry Avins" <jya@ieee.org> wrote in message... > >> You can reach the limits of audible frequencies at sampling rates far >> below 96 KHz. You can exceed the accuracy of tape or vinyl with numbers >> smaller that 32 bits. > > 16 bit, 44.1khz is more than adequate for accurate reproduction within > the range of human hearing... that's why it was chosen 20 years ago > and that is why it is still the standard digital audio delivery medium today. > > If anything, the 'bar' of acceptable quality is being progressively and > willingly lowered by MP3, ATRAC and the ongoing host of other data > compression codecs and schemes.Sure. There are good arguments to be made for more than 16 bits in places along the processing chain, but 16 bits dithered down from the processing word width is plenty for reproduction. (You say you can hear that 17 bits sounds better? Listen in good health!) The anti-alias and reconstruction filters are easier to build (fewer compromises needed) at the somewhat higher sample rate of 48 KHz, but that's not the issue. (Especially for me, with my 4 KHz cutoff. :-( ) I try to avoid numbers in threads like this because they often lead to unproductive digressions. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Reply by ●April 16, 20072007-04-16
David Morgan (MAMS) wrote:> "Jerry Avins" <jya@ieee.org> wrote in message... > >> You can reach the limits of audible frequencies at sampling rates far >> below 96 KHz. You can exceed the accuracy of tape or vinyl with numbers >> smaller that 32 bits. > > 16 bit, 44.1khz is more than adequate for accurate reproduction within > the range of human hearing... that's why it was chosen 20 years ago > and that is why it is still the standard digital audio delivery medium today. > > If anything, the 'bar' of acceptable quality is being progressively and > willingly lowered by MP3, ATRAC and the ongoing host of other data > compression codecs and schemes.Sure. There are good arguments to be made for more than 16 bits in places along the processing chain, but 16 bits dithered down from the processing word width is plenty for reproduction. (You say you can hear that 17 bits sounds better? Listen in good health!) The anti-alias and reconstruction filters are easier to build (fewer compromises needed) at the somewhat higher sample rate of 48 KHz, but that's not the issue. (Especially for me, with my 4 KHz cutoff. :-( ) I try to avoid numbers in threads like this because they often lead to unproductive digressions. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Reply by ●April 16, 20072007-04-16
Richard Dobson wrote: ...> Evidence is increasingly being produced (NOT by audiophiles addicted to > snake-oil) to show that (at least for people not impaired by age, discos > etc) sounds well above 20KHz are audible and significant; especially for > the obvious bright sounds such as trumpets, cymbals as so on.Until recently, my daughter would be driven up the wall by a monitor with a 22.5 KHz horizontal rate. Now that she's over 40, it doesn't bother her much. Back when my hearing went up to 10 KHz, frequencies above that that I couldn't hear in isolation nevertheless altered the timbre of sounds I could hear. I never figured out how that could be, but there it was. (Paul Weathers demonstrated it to me.) Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Reply by ●April 16, 20072007-04-16
David Morgan (MAMS) wrote:> "Fred Marshall" <fmarshallx@remove_the_x.acm.org>.... > >> Jerry, >> >> I assumed a perfect quantizer that decides which level to output based on >> the input being within 1/2 a level distance. Thus, the peak error is 50% of >> a level. They are never a full level off with a perfect quantizer. >> >> Because the amplitudes are uniformly distributed, the errors peak at 1/2 a >> level - so I guess the expected abolute value of an error *is* 1/4 a level. >> Good catch. > > > WTF are you babbling about ?It's perfectly clear to me. Maybe you should read that part of the thread again. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Reply by ●April 16, 20072007-04-16
Jerry Avins wrote:>> 16 bit, 44.1khz is more than adequate for accurate reproduction within >> the range of human hearing...It is just enough for the consumer audio. Assuming the signal is normalized properly.> that's why it was chosen 20 years ago >> and that is why it is still the standard digital audio delivery medium >> today.No. The main reasoning behind the CD is the extremely cheap reproduction. As for 16 bits, it was a pinnacle of technology of the old days.>> If anything, the 'bar' of acceptable quality is being progressively and >> willingly lowered by MP3, ATRAC and the ongoing host of other data >> compression codecs and schemes.It is not as straightforward. The compression schemes at 256+ kbps can actually deliver the better quality then CD.> > Sure. There are good arguments to be made for more than 16 bits in > places along the processing chain, but 16 bits dithered down from the > processing word width is plenty for reproduction.Well. The first listeners were very happy about Edison's phonograph, too. It is the difference which is perceived as the quality. Also, you should not underestimate a pleasure of possessing a coolest super advanced digital exclusive gadget. (You say you can hear> that 17 bits sounds better? Listen in good health!) The anti-alias and > reconstruction filters are easier to build (fewer compromises needed) at > the somewhat higher sample rate of 48 KHz, but that's not the issue.Specmanship is the issue. With Fs = 44.1kHz, it is difficult to achieve the full response up to the nice even number of 20kHz.> (Especially for me, with my 4 KHz cutoff. :-( )You are not the representative buyer anyway. That stuff is designed and manufactured mainly for the little boys from 17 to 25 y.o.> I try to avoid numbers in threads like this because they often lead to > unproductive digressions.It is not possible to apply any technical arguments in the areas of fashions, beliefs, religions and superstitions. Vladimir Vassilevsky DSP and Mixed Signal Design Consultant http://www.abvolt.com
Reply by ●April 16, 20072007-04-16
Vladimir Vassilevsky wrote:> > > Jerry Avins wrote: > > > >>> 16 bit, 44.1khz is more than adequate for accurate reproduction within >>> the range of human hearing... > > It is just enough for the consumer audio. Assuming the signal is > normalized properly. > >> that's why it was chosen 20 years ago >>> and that is why it is still the standard digital audio delivery >>> medium today. > > No. The main reasoning behind the CD is the extremely cheap > reproduction. As for 16 bits, it was a pinnacle of technology of the old > days. > > >>> If anything, the 'bar' of acceptable quality is being progressively and >>> willingly lowered by MP3, ATRAC and the ongoing host of other data >>> compression codecs and schemes. > > It is not as straightforward. The compression schemes at 256+ kbps can > actually deliver the better quality then CD.Please quote more accurately. I didn't write any of the material above. ...>> I try to avoid numbers in threads like this because they often lead to >> unproductive digressions. > > It is not possible to apply any technical arguments in the areas of > fashions, beliefs, religions and superstitions.But is _is_ possible to avoid numbers when explaining to an intelligent reader the necessary relation between bandwidth and sample rate, how the necessarily finite precision of numbers affects what is reproduced, and that the signal "between the samples" is all there. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Reply by ●April 16, 20072007-04-16
"David Morgan (MAMS)" <findme@m-a-m-s.comC/Odm> wrote in message news:0aGUh.2900$nU4.922@trnddc03...> > "Fred Marshall" <fmarshallx@remove_the_x.acm.org>.... > >> Jerry, >> >> I assumed a perfect quantizer that decides which level to output based on >> the input being within 1/2 a level distance. Thus, the peak error is 50% >> of >> a level. They are never a full level off with a perfect quantizer. >> >> Because the amplitudes are uniformly distributed, the errors peak at 1/2 >> a >> level - so I guess the expected abolute value of an error *is* 1/4 a >> level. >> Good catch. > > > WTF are you babbling about ? >I take it from your tone that you don't want an explanation and that your question is pejorative?? If not, please accept my apologies. Otherwise: Just DSP stuff. If you don't understand, don't worry about it. Fred
Reply by ●April 16, 20072007-04-16
"Jerry Avins" <jya@ieee.org> wrote in message news:ZdadnQk4-q4Gz7_bnZ2dnUVZ_qzinZ2d@rcn.net...> Mistype. A slip of the mind. Goof, whatever. There were 9 pictures, two of > them of the SNR equation. See my revised missive. > > Jerry??? Jerry, Here is what I did: Copy and paste the equation into the body of the email - that is all. Here is what shows SENT at my end: An attachment that is one .png file. When opened it is a rather large white background (which I assumed is what you meant by your backyard on a snowy day) with the equation in black font in the center. Here is what I see in my usegroup reader: Same thing as SENT. 9 images?????? Fred
Reply by ●April 16, 20072007-04-16
Fred Marshall wrote:> "Jerry Avins" <jya@ieee.org> wrote in message > news:ZdadnQk4-q4Gz7_bnZ2dnUVZ_qzinZ2d@rcn.net... > >> Mistype. A slip of the mind. Goof, whatever. There were 9 pictures, two of >> them of the SNR equation. See my revised missive. >> >> Jerry > > ??? > > Jerry, > > Here is what I did: > Copy and paste the equation into the body of the email - that is all. > > Here is what shows SENT at my end: > An attachment that is one .png file. > When opened it is a rather large white background (which I assumed is what > you meant by your backyard on a snowy day) with the equation in black font > in the center. > > Here is what I see in my usegroup reader: > Same thing as SENT. > > 9 images??????I emailed you the attachment I still can see. Mysteries abound! Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
