On another note, I had time at lunch so built the excel sheet I mentioned yesterday.
Since Lavry liked 17Khz, I used it.
I built the sheet to display two channels. I set the sampling rate, and set the sine frequency of interest as well as the angular separation between the two sines.
So this plot shows 2 17Khz sines sampled at 44Khz, with a 10 degree angular separation between the sines, and simultaneous sampling.
Note that the dots are exact out to 15 places in amplitude. (that was the resolution of PI in excel.)
Also note that excel did the line fit, I had no say in how it does the fit.
Also, the data points do indeed mimic Lavry's 17Khz sampled 44.1K prefiltered.
Of note, there are distinct amplitude and phase differences throughout the graph. Given two identical channels filtering that mess, the question is...will the reconstructed pair have an exact and continuous phase shift of 10 degrees in this case?
jn
Since Lavry liked 17Khz, I used it.
I built the sheet to display two channels. I set the sampling rate, and set the sine frequency of interest as well as the angular separation between the two sines.
So this plot shows 2 17Khz sines sampled at 44Khz, with a 10 degree angular separation between the sines, and simultaneous sampling.
Note that the dots are exact out to 15 places in amplitude. (that was the resolution of PI in excel.)
Also note that excel did the line fit, I had no say in how it does the fit.
Also, the data points do indeed mimic Lavry's 17Khz sampled 44.1K prefiltered.
Of note, there are distinct amplitude and phase differences throughout the graph. Given two identical channels filtering that mess, the question is...will the reconstructed pair have an exact and continuous phase shift of 10 degrees in this case?
jn
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Are you referring to different filters and/or sampling rates, the ultimate source is still BW limited?
Boths. But the effect are not of the same character.
Audio is a mess. (L'audio, c'est le bordel.)
For example, I do not exclude that the differences felt are not due to our hearing system, but rather to the way in which our speakers accelerate. But, when it works, why bother ?
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Jan Didden once participated in a test with a large group while playing music with lots of content above 20 Khz. There was a switchable steep analogue LPF installed after the D/A to reduce BW to 18Khz when I remember correctly.
Outcome as he mentioned was felt as quite embarrassing because the audience preferred the 18Khz limited sound.
Jan, are you listening ?
Hans
It is NOT outdated for 24 bith and higher; the latest achievements in high speed SAR ADCs are ppm level INL maximum, and no missing codes at 20 bits. That is a far cry from what 24bit sigma-delta ADCs can do. These 24 bit and over sigma-delta ADCs are still trading speed over accuracy, so dithering is still required.
But the point is, there's no need to push audio grade ADC over what we already have; the 20bit SAR ADC running @100MHz bit rate on my bench is industrial grade and it makes absolutely no sense to be used for audio reproduction; I'm trying it for instrumentation purposes, and it is very good (thanks chris719 for bringing it to my attention, meantime I found other ADCs in the same performance range).
If by "what we have" you refer to a system that exhibits a 50% rolloff at 17Khz, with no details on ITD, I cannot agree with you.
Lavry's intent in the article is unknown, but his main premise is that what we have is good enough and better is too expensive.
Advances in tech render the cost factor moot, and as you show, conversion as well.
jn
So to conclude, there are many different opinions.
Hans
What, that Richard is stubborn and pig headed?? No, I believe we all have the same opinion on that...
badaboom..Richard, the sequence of posts was just too funny, couldn't resist. You owe me a slap upside the head for that one...
jn
... And very different experiences.So to conclude, there are many different opinions.
Thats fine and it works for many things. But from others is a lot of speculation on if it will or wont sound more accurate. And, on and on it goes into Nyquist is being violated and blah blah. It just gets weird to me.
Many need to read the work of those who did careful listening tests at Harmon Int. They found that what audiophile had noticed for a long time was true plus some new info. That lower distortion and a flat and wide BW was preferred by most people. I call it accurate.
I told you all, you need to compare to the real thing you are listening to. I gave a way to compare a well known voice to your system to determine accuracy. The cymbal is small enough and cheap enough to bring into the home and hit it with a stick. Does your digital/Cd system sound anything close to it?
Is it just me or is it many. here is an excerpt from a drummer who listened and heard differences easily.
--------------------------------------------
I used real ride cymbals and hi hat cymbals because I didn’t like the feel of ride cymbal pads or hi hat pads, but I was also beginning to notice something, and now we are coming to the point of this dissertation. The sounds of the crash cymbals seemed incomplete. They didn’t have the brightness or clarity that real cymbals have. There was a distinct difference between the real crash cymbals that I had and the samples of those exact same cymbals that I was triggering from the cymbal pads.
Now, keep in mind that I was (and still am) using my reference audio system to play the drum samples through. This consists of a Pure Class A tube preamplifier, two 1,200 watt McIntosh monoblock power amplifiers, and the those two ribbon speakers, each of which has a 60” ribbon and four 12” woofers. So, I could not only hear everything in the samples, but also, what was missing (not to mention that I can blow the walls out with all that power).
The cymbal samples were recorded at 44.1 kHz, 16 bit, which is the same quality as found on a CD, and is the sample rate supported by the drum triggering module.
So, I expanded my horizons and began recording cymbal sounds at higher sampling frequencies, and discovered that cymbals produce frequencies well above 20 kHz (the limit on a CD is 22 kHz), and in fact, above 30 kHz all the way out to 60 kHz, maybe even a bit further. The samples recorded at 44.1 kHz also sounded mushy, and when I looked at the spectrum of the recorded samples, I realized why. Cymbals produce what is probably the most complex sound of any musical instrument. When you hit a crash cymbal, the frequencies it is making all at the same time span 30 Hz up to well beyond 30 kHz. That is very tough to reproduce with basic CD quality sampling."
--------------------------------
Why dont you guys get up and try some things and then listen with a high quality system.
Yeah, Scott I am stubborn and pig headed. Really. What does it take to get you guys unstuck?
THx-RNMarsh
Many need to read the work of those who did careful listening tests at Harmon Int. They found that what audiophile had noticed for a long time was true plus some new info. That lower distortion and a flat and wide BW was preferred by most people. I call it accurate.
I told you all, you need to compare to the real thing you are listening to. I gave a way to compare a well known voice to your system to determine accuracy. The cymbal is small enough and cheap enough to bring into the home and hit it with a stick. Does your digital/Cd system sound anything close to it?
Is it just me or is it many. here is an excerpt from a drummer who listened and heard differences easily.
--------------------------------------------
I used real ride cymbals and hi hat cymbals because I didn’t like the feel of ride cymbal pads or hi hat pads, but I was also beginning to notice something, and now we are coming to the point of this dissertation. The sounds of the crash cymbals seemed incomplete. They didn’t have the brightness or clarity that real cymbals have. There was a distinct difference between the real crash cymbals that I had and the samples of those exact same cymbals that I was triggering from the cymbal pads.
Now, keep in mind that I was (and still am) using my reference audio system to play the drum samples through. This consists of a Pure Class A tube preamplifier, two 1,200 watt McIntosh monoblock power amplifiers, and the those two ribbon speakers, each of which has a 60” ribbon and four 12” woofers. So, I could not only hear everything in the samples, but also, what was missing (not to mention that I can blow the walls out with all that power).
The cymbal samples were recorded at 44.1 kHz, 16 bit, which is the same quality as found on a CD, and is the sample rate supported by the drum triggering module.
So, I expanded my horizons and began recording cymbal sounds at higher sampling frequencies, and discovered that cymbals produce frequencies well above 20 kHz (the limit on a CD is 22 kHz), and in fact, above 30 kHz all the way out to 60 kHz, maybe even a bit further. The samples recorded at 44.1 kHz also sounded mushy, and when I looked at the spectrum of the recorded samples, I realized why. Cymbals produce what is probably the most complex sound of any musical instrument. When you hit a crash cymbal, the frequencies it is making all at the same time span 30 Hz up to well beyond 30 kHz. That is very tough to reproduce with basic CD quality sampling."
--------------------------------
Why dont you guys get up and try some things and then listen with a high quality system.
Yeah, Scott I am stubborn and pig headed. Really. What does it take to get you guys unstuck?
THx-RNMarsh
What, that Richard is stubborn and pig headed?? No, I believe we all have the same opinion on that...
Richard, the sequence of posts was just too funny, couldn't resist. You owe me a slap upside the head for that one...
jn
Richard,
I make you an offer.
Send me a representative .wav file recorded in HD format and without any prejudice I will listen to this fragment in your format and also to one that has been decimated to 44.1/16 format.
I will tell you my findings as soon as possible if I can hear a difference.
Send it to hapolak@me.com.
Hans
I am sure it does. As somebody else mentioned, acceptable ignorance has it's limits.
No, post it here
Remember saying this Richard? : "If a huge majority of people from all over the planet say they hear something the same way as the others.... That should be good enough."
You can do this easily yourself. There are music sites with CD and high sample rate 24b versions of each. Plus you get the enjoyment of picking the music you like.
THx-RNMarsh
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I can't believe you think that signal reconstruction is equivalent with Excel interpolating, allegedly with some polynomial, over a few periods. You could let Excel draw segments between points and get an even more spectacular effect.
You are still missing the elementary fact that digitizing a few 17KHz sine periods at 44.1KHz is violating Nyquist, since there is a lot of energy beyond 17KHz that you wish to be reconstructed. The spectra of a few sine periods extends to infinity, only an infinite sine has the spectra of a delta function at fo.
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No, post it here
Lets do this in parallel and not series .... everyone do it and everyone listen and everyone decide.
If over time and place and culture, many people report the same findings, it is accepted.
OK? Got it? Bye. Got a lot of hi-rez downloads I am interested in.
THx-RNMarsh
Lets see what other trouble I can stir up here..... carry on your fights. Good luck syn08 with proving no one can hear improvement over CD.
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