Hi Klas,
I will reply via private mail in order to prevent any further
misinterpretation ;-)
Raimund
> Thanks Raimund, just one more question:
>
> For how long back in time would you say the below judgements go?
>
> I mean, it is quite inadequate to judge the specs of the single
chip. As a
> user, I have to judge about the whole assembly. Example: When your
D3 worked
> fine in 1991, I know for sure how badly my own pc-soundcard
converter
> worked, regardless of poor shielding or not.
>
> Klas.
>
>
>
> Would At 12:21 2003-08-17 -0000, you wrote:
> >Klas Strandberg <> wrote:
> >
> >>Thanks Raimund. What I would like to understand a bit is how
good
> >the simple
> >>AD, DA converters in modern walkman type DAT's and MD's are.
When
> >using a
> >>Portadisc compared to a cheap Sharp MD, what role does the AD,
DA
> >converters
> >>play?
> >
> >I would say, that there are only minor differences between the AD
> >and DA converters chips between the various devices. Today, these
> >chips are very cheap (5 ... 20 $) and are generally of a high
> >quality. However, the overall quality of a recorder depends also
on
> >other parts that will make the difference. Among these things are
> >the pre-amplifier and the specific design of the recorder (e.g.
> >shielding against internal digital noise). I still have not
compared
> >the Portadisk to the cheaper MD's. Besides my mini-laptop
equipped
> >with an external 24 bit audio interface, I'm still using a
consumer
> >DAT recorder SONY TCD-D3 recorder (purchased at about $600 in
1991).
> >This old device still works satisfying for my purposes and I can
not
> >find any artifacts that could be attributed to its AD converter.
> >
> >>And the converters on cheap sound cards?
> >
> >The converter chips on cheap sound cards might be the same models
> >than those in consumer MD recorders. Therefore, here applies the
> >same I mentioned above. More important than the A/D converter
itself
> >is the shielding against digital noise and the noise performance
of
> >the pre-amplifier (even that of LINE-IN if you want to have the
> >maximum possible dynamic range). Especially the microphone
inputs
> >of cheap internal soundcards are often of a poor quality
(certainly
> >in laptop computers).
> >
> >>Will a typical cheap converter on a standard sound card make
> >visible changes
> >>on a sonogram?=A0
> >
> >No. However, it depends on the dynamic range that you wish to
> >display on the spectrogram. Usually (e.g. for species
identification
> >or other sound parameter measurements), it is not required to
> >display any signals below -60 dBFS. This level is far above the
> >higher inherent noise levels of cheaper soundcards. Additionally,
> >the potentially lower dynamic range of cheap soundcards will be
> >masked by the environmental noise and the inherent noise of the
> >microphone that is already present in a recording. If you want to
> >display the full dynamic range of the recording (including the
> >softest background noise) on a spectrogram, the higher inherent
> >noise of cheap soundcards will become visible (but only if that
> >noise is stronger than that of the original recording).
> >
> >>Would you say that cheap AD, DA converters cause more trouble
than
> >ATRAC and
> >>MP3??
> >
> >No! Cheaper AD converters may add a very small amount of
additional
> >noise only (leading to a dynamic range of e.g. 85 dB instead of
92
> >dB). There are no other significant distortions. The artifacts
that
> >occur in ATRAC or MP3 may lead to extremely degraded dynamic
ranges
> >of less than 20 dB at worst cases (which will of course never
occur
> >so extremely in common nature recordings).
> >
> >To my mind, the problem in ATRAC is, that the potential artifacts
> >are highly unpredictable. Sometimes, the sounds will be recorded
> >properly, but in some special cases you will get unreliable
results.
> >This is the reason why I always prefer DAT or other recording
> >techniques without compression. I'm considering to buy the new
> >PMD670, even if it has only a resolution of 16 bits. As we have
> >discussed earlier, the limited dynamic range of a 16 bit system
> >would be sufficient for most nature recordings...=20=20
> >
> >Regards,
> >Raimund
> >
> >
> >
> >
> >To unsubscribe from this group, send an email to:
> >
> >
> >
> >
> >Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
> >
> >
> Telinga Microphones, Botarbo,
> S-748 96 Tobo, Sweden.
> Phone & fax int + 295 310 01
> email:
>
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