--- In Dan Dugan <> wrote:
>Thank you, Raimund, this is a very nice illustration of what's going
>on in a typical good psychoacoustic data reduction scheme. Could you
>add the color/level scale to your spectrogram illustrations?
Yes, a color level scale would be useful. Unfortunately, this
feature is not supported in that kind of spectrographic display at
the moment (most users use that software to measure amplitudes by
cross-hair cursors and other measurement techniques). It is one of
my priorities to add such a scale to color spectrogram displays. I
will then update the posted spectrograms.
In order to illustrate the quantity of the effects I have just added
two short-time spectrum displays with dB scales, showing the effects
at a worst case situation:
http://www.avisoft-saslab.com/compression/compression.htm
>If I were to ATRAC process and unprocess
>your test file, without analog conversions, would you be willing to
>plot and post those results too?
Yes, of course. That would be great because I do not have access to
an ATRAC system at the moment.
> What compromises you accept in exchange for economy and portability
>are always up for discussion, and ultimately a personal choice. I
get
>fabulous, publishable recordings of both music and nature on a cheap
>Sharp portable MD! I agree with Walt that the degradations of "lossy
>compression" recording are almost always insignificant for both
>personal and scientific uses, and your excellent analysis of MP3
>doesn't change that opinion. Thank you for making the discussion
more
>objective.
I agree. As mentioned before, other effects present in real-world
recordings as reverberation and background noise, will also degrade
the spectrographic representation. I'm also impressed by the
abilities of the current audio compression technology. Today it is
possible to store hundreds of hours of music on a single harddrive
at an excellent quality. So I would not hesitate to use these
systems for entertainment (and perhaps for some less complex nature
sounds).
Thank you very much for your kind reply. I admit, that I was very
close to the point of breaking off any further communication to this
group. I had the impression, that the majority was infected by some
kind of collective MiniDisk delusion ;-)
I really enjoy the helpful advice on microphones and recording
techniques I got from this group.
Regards,
Raimund
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