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Old 21st July 2010, 12:04 PM   #4981
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Burkhard Vogel gives the dynamic range on Vinyl Records cut with DMM as 72 dB. I have records cut Direct to Disk from Pauler Acostics that sound very quiet. Anyway, CD can sound good too. Commercial CD players often lack a good PSU and analog stage though.
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Old 21st July 2010, 12:23 PM   #4982
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Sorta like saying Madman Muntz' 4-track has the potential, but lacks the mechanical details.

Click me for a black-out =>
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Old 21st July 2010, 12:27 PM   #4983
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Quote:
Originally Posted by Rod Coleman View Post
Dithering requires averaging doesn't it?
Depends on what you mean by "averaging." It does in the same sense that tape bias "requires averaging."

Seriously, read the Lipshitz papers.
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Old 21st July 2010, 03:30 PM   #4984
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Averaging, for instance, as in the Daqarta link you posted:

Daqarta - Dither: Noise + Averaging = Resolution

I am sure there are many clever ways to reduce the impact of this kind of processing, but it still doesn't make the performance equal to doing it properly where real music is concerned

The effect is well illustrated by Terry's words a few posts ago:

Quote:

Down sample to 44.1 / 24 using a) Tony Faulkners averaging program (no
LPF) and b) a high quality SRC program (typically with with brickwall
filtering).

Use whatever dithering sounds best for that particular program material to
reduce from 24 bits to 16 bits.

Listen carefully at every step of the process to see the progressive
changes and where the biggest subjective quality reduction is.

I have done this exact process myself. The results can be surprising.
in other words, the nature of the processing needs to be tailored to the specifics of the music, in order to minimize the degradation! I don't find this surprising, it is characteristic of trying to squeeze the best out of a skimped-resource system.
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Old 21st July 2010, 03:48 PM   #4985
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Quote:
Originally Posted by Rod Coleman View Post
I am sure there are many clever ways to reduce the impact of this kind of processing, but it still doesn't make the performance equal to doing it properly where real music is concerned
Again, you've avoided the question of the bias signal on the analog tapes of recordings that you have found satisfying.

The effects of dither on resolution of a CD were clearly shown in the Stereophile review I posted (along with almost all of their other CD player reviews). FAR better performance when it comes to resolution than excellent analog systems. And the Lavry link that Terry so kindly posted. But most of all, the Lipshitz papers, which no-one besides me seems to have bothered to read.

I'm reminded of Max Planck's famous dictum:

"A new scientific truth does not triumph by convincing its opponents and making them see the light, but because the its opponents eventually die, and a new generation grows up that is familiar with it.”

When you have some data showing the audibility of a 16/44 A/D-D/A inserted into an analog signal chain, I'll be most interested to see that.
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Old 21st July 2010, 03:49 PM   #4986
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Well, no one seems to want to discuss the differential (if any) between listening to live mics and recorded mics (your choice of recording method)??

As far as noise on a recording - it is "random" noise when it happens, but once it is recorded it is determinate noise, yes? So, it might be instructive to look at the spectrum (or listen to it)??

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Old 21st July 2010, 04:11 PM   #4987
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Quote:
Originally Posted by Rod Coleman View Post
Dithering is a crutch for a crippled medium that does not have enough resolution for the job it tries to undertake.
Where do you get this nonsense, seriously? Is there a textbook which I can have a peek at which dishes this stuff out?

Quote:
Until then, my ears tell me it doesn't work, or is not implemented well enough in musical media that I can actually buy (CDs) of music I want to hear.
I favour the latter explanation - why do you go for the former?

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So I play lots of LPs, the best of which make a fool of CD.
Interesting how the pitch is queered - comparing individual, cherry picked LPs with a format. I'd say that the best that can be said here is that your LP playback system makes a fool of your CD playback.
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Old 21st July 2010, 04:12 PM   #4988
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Quote:
Originally Posted by SY View Post
The same as any other signal. Why would it be any different? A signal is just a single valued function.

When you have data showing audibility of a level-matched input versus output comparison of a 16/44 A/D-D/A chain on an analog signal, I'll be most interested to see it.
Sy,

Not to pick on you, but there are some issues that always seem to get confused.

Number of bits might mean the limit to resolution, but not always. For example an 8 bit converter should have 256 unique non-overlapping step sizes. Many 24 bit converters do not do this as do some of the older 16 bit units. The original CD's were only nine bit linear because to get the 16 bits they staged a nine bit unit with a seven bit device.

44 is the sampling rate. But it does not include how accurate the clock or even the sample time can be. In some early products the clock was divided by a non-binary number and although you got the right number of cycles per second the width was not uniform.

There are many approaches to conversion. The ratiometric or single bit converters were first used in the 1940's. A simple clamped signal and an accurate clock made a very serviceable converter. After some different designs the R-2R became a very widely used design. These designs of course work differently and have different effects on the signal being processed.

As all converters use analog input and output it is important to note that there are more issues than "is the analog as good as the digital?" When you charge a capacitor from a voltage source through a resistance the curve is an inverted exponential curve. Same for your current limited inductor, but of course you rarely see them in modern low level filters. So when you use a low pass filter to clean up your step jumps it is not a true linear average. This also is why timing errors are of greater importance than it would seem at first glance.

When you over sample, the sampling should be uniform in time. This gives us a linear average. If everything is working.

When you add something (noise, dither or a deliberate funny waveform) to the input of a converter properly it changes things. If you are oversampling you can with some care get increased resolution depending on a few issues. Some work has been done on this but there is still more to do. If you are at the Nyquist limit you may prefer the results over the non added version. This work has been done pretty thoroughly but there may still be a surprise or two to come.

What should be obvious is that the distortion from any added signal process is very hard to predict because the step size error at the lowest resolution is not constant at 1/2 of a bit but varies throughout the entire range.

So YES I can make a 16/44 chain that will sound bad to almost anyone. When I read some of the experiments using equipment that I know is not really as claimed or when the math shown does not understand the importance of how the filtering is done, some room for inquiry is left.

ES
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Old 21st July 2010, 04:19 PM   #4989
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Quote:
Originally Posted by bear View Post
Well, no one seems to want to discuss the differential (if any) between listening to live mics and recorded mics (your choice of recording method)??

As far as noise on a recording - it is "random" noise when it happens, but once it is recorded it is determinate noise, yes? So, it might be instructive to look at the spectrum (or listen to it)??

_-_-bear
Bear,

Long ago I tried binaural recording. In theory it should be possible to use a mold of your head to make a recording that to you would be the same as being there, when played through matching headphones.

I never got this to work for me. Small mics and headphones were never good enough never mind the electronics.

Of course the obvious problem is even a mold of my head is too big to fit through most doors!

ES
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Old 21st July 2010, 04:19 PM   #4990
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Quote:
Originally Posted by simon7000 View Post

So YES I can make a 16/44 chain that will sound bad to almost anyone. When I read some of the experiments using equipment that I know is not really as claimed or when the math shown does not understand the importance of how the filtering is done, some room for inquiry is left.

ES
Ed, I'm certain you can. I probably could, too.

But what remains standing is that, using standard, competently designed 16/44 systems (of which there are many, many), there is still NO data showing audibility when inserted into an analog signal chain. The idea that the resolution of a true 16 bit system (of which there are many, many, probably the majority) is somehow less than analog systems like tape and vinyl is just flat-out incorrect.
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