More > JRiver Media Center 22 for Windows

Sox Sideshow

<< < (10/10)

pschelbert:
Hi

there are different ways of doing upsampling. one is inserting zeros and then convolute with a filter to do the approximation, others are calculating with spline or other fitting tools the samples. How SOX for example does it, I do not know.

Upsampling makes the analog reconstruction filter easy. Thats it. The hard job is done by digital filtering then a relaxed analog filter does the reconstruction (remove of the stairs and the noise).
There is a lot of theory and explanation for that topic of AD and DA conversion in the links I provided and elsewhere (a traditional book  on this is "Oppenhein Schafer, discrete time signal processing", the classic book).
See: second edition 1998/1999, page210: Oversampling and DA Conversion

If you do that in the chip or externally with software, it is more or less the same result.

Sound of DAC (prelim results):
Thats just the result of a blind test versus the very real original sound file.
People in a blind test got everything wrong, they could not tell which file is right not even hear a difference of two different files , one the original, one the file through the DAC.

If there is a difference I hear from people in forums always "you can hear a sound difference even if you cannot measure".
What the test gets clear: you cannot hear a lot, even if the soundfile is rather different. You can measure much more and much better than anybody can hear.
This is valid for DAC. A reasonable good DAC is by far better than anybody can hear.

Loudspeaker, headphone, microphone are a much more complicated world, its 3D, so not as easy to characterize....

Peter

Navigation

[0] Message Index

[*] Previous page