I made progress on getting the impulse response and transfer function of
the filters sox is making for me. (It took me a while to figure out how
to create a custom wav file to process with sox that contained just an
impulse.)
The attached jpeg's show the results for
Code:
--------------------
sox -D -V myimpulse.wav -t flac -b 24 myfilt.wav rate -b 85 -Mav 96k
--------------------
Note that I had to create a flac file because the 24-bit wav files
created by sox 14.3 were invalidly formated according to all my programs
that can read wav files (foobar2000, etc).
I have done my best to make the filter as relaxed as possible by
starting at 85% of the full bandwidth (-b 85) and allowing some aliasing
of the music signal (-a). The more relaxed the filter the shorter the
impulse response tail will be, but I haven't found a way to make the
filter as short as the one in Ayre white paper yet. The current version
rings out in about 500 micro seconds.
If someone who owns a Transporter is interested to try, it should now
be possible to compare your favorite 16/44.1 lossless file and the sox
"Apodizing" filter upsampled version.
The upsampled version could be create e.g., as follows:
Code:
--------------------
sox -D -V mytesttrack.flac -t flac -b 24 myfilt.flac rate -b 85 -Mav 192k
--------------------
If anyone does a listening test, I'd love to hear what you think.
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|Filename: freqz_85_Mav.jpg |
|Download: http://forums.slimdevices.com/attachment.php?attachmentid=8344|
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--
dsdreamer
----------------------
"Dreamer, easy in the chair that really fits you..."
------------------------------------------------------------------------
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View this thread: http://forums.slimdevices.com/showthread.php?t=69145
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