Raimund,
Creative's response to Graham says that MP3 recording duration=20
on the Nomad Jukebox is now limited only by the HD size , so it
would be interesting to know if the 3 hr limit on *.wav file
recording you noted has also been altered. I was told by a
knowledgeable user that one early Jukebox iteration could
record *.WAV files with no duration limit and the limit was added
later.
For Graham, it should be simple enough to abandon the light,
expensive rechargeable lithium JB3 battery packs and assemble
a bulkier external battery pack with a runtime well in excess of
ten hours, using either NiMH or a gelled lead acid batteries,
voltage regulated as needed. I think I saw something on
www.nomadness.net about the acceptable voltage input range,
but it might be simpler to test it than find the discussion.
Thanks for the point about the PC-only code on the Neuros web
site.In an email exchange with their chief technical officer about
firmware modification, I learned they receive inquiries from
academics moderately frequently. They are open to collaboration
with outside programmers (avoiding 'reverse engineering' to
achieve a non-standard operation) or doing a custom package. I
indicated there might be a niche market in research and
avocational nature recordists and pointed them to various
bioacoustic web sites.
Your point about the possibly short life of even well executed,
innovative devices is painfully true. I've encountered several
discussions that suggest the Nomad JB3 is close to end-of -life
(much bulkier than most of the current competing MP3 units, not
many potential purchasers care about uncompressed audio,
etc.).
Having grappled with recording bat audio and ultrasound with
different PCMCIA 350-500 kHz AtoD converters, laptops and
software packages, your Avisoft integrated system (USB
hardware, software with selective event capture) is a very
appealing concept. I would certainly like to purchase one or
more for high resolution recording and analysis when funds
permit.
With different questions in mind and the desire to install several=20
bat monitoring units over a large area that would be visited and
downloaded infrequently, we 've assembled several units with
the Anabat detector and storage zcaim, which records highly
'compressed' representations (frequency division with no
amplitude retention) of acoustic events (including bird, bat and
insect calls) on compact flash cards. Daily start and stop times=20
are programmed on the card and power drain is such that a five
watt solar panel with a 1.3 Ahr battery will run the system most
of the year in open western N. Am. habitats.
The simplified acoustic representation means that a 512 Mb CF
card is adequate to record 1000-2500 multi-pulse bat 'passes'
per night (e.g., lowland river edge in summer) for more than six
weeks. The practical constraint on download intervals is set by=20
habitat linked concerns about data loss from damage and
biofouling (such as curious bears or wasp nests on microphone
grids). We need different tools for different tasks and options
(storage density , device power requirements, unit cost) are
gradually improving, but this seemed an affordable approach to
exploring variability and seasonal patterns of bat acoustic activity.
Bill
--- In
wrote:
> Bill,
>
> Thanks for your note. I have to admit that I've never used the
Nomad JB3 for
> long-term recording. I use it primarily for listening music. I have
copied
> my entire music CD collection (150 albums, MP3-encoded at
256 kbps) onto it's
> hard drive and I'm very satisfied with it's performance for that
application
> (it has been designed for that purpose).
>
> You are correct, the JB3 has an additional limitation on the
recording time
> for a single file. I just checked my JB3 (firmware version
1.32.02p). In
> uncompressed .WAV file recording, the maximum duration is 3
hours (independently
> of the sample rate and the number of channels). In the .MP3
recording mode,
> the maximum duration is 10 hours (the selected bit rate does
not matter).
>
> Thanks for the link to the Neuros HD backpack system. That
seems to be
> indeed an interesting alternative to the Nomad JB3.
>
> As far as I understand, the source code provided on their
website is the
> source code for the NSM PC software only =96 not the firmware
that resides inside
> the device. In fact, it would be extremely difficult to edit the
firmware of
> the device. That would require detailed and very special
knowledge. So, even
> a well-trained engineer would require several months (or even
years) to
> become familiar with the hard- and firmware architecture. And
there would be the
> potential risk that all the efforts get lost because the production
of the
> device may expire suddenly...
>
> So, in my opinion it is an illusion to get a cheap and
full-functional
> recording device for such special applications as long-term bat
sound recording.
>
> Currently, the best solution for long-term monitoring of animal
sounds would
> be to use a PC -based system. In conjunction with appropriate
software (e.g.
> Avisoft-RECORDER http://www.avisoft.info/recorder.htm), it
would be possible
> to set-up the system for a sound-activated recording mode.
Special
> techniques (amplitude thresholds in pre-defined frequency
intervals and entropy
> filters in conjunction with a pre-recording buffer) can help to
reject unwanted
> sounds from triggering.
>
> The main drawback of using a continuous recording mode
would be the huge
> amounts of data that have to be analyzed afterwards.
>
> Regards,
> Raimund
>
>
> > I've been interested in (relatively) inexpensive HD based
> > recorders for similar multi-station audio range monitoring
> > purposes (birds, downconverted bat audio) and so have
> > followed Nomad JB3 disussions on various net venues. My
> > impression (with no hands-on experience ... which Raimund
can
> > perhaps correct) is that the JB3, at least in more recent
firmware
> > versions which offer record level controls and the like, may
have
> > a firmware limit of about two hours on unattended recording
> > duration (independent of the 2 gb wav file maximum).
> >
> > As far as I know, the Neuros HD backpack system
(20,30,40gb)
> > (http://www.neurosaudio.com/) is the only other MP3
oriented
> > HD recorder which is also capable of uncompressed *.wav
> > recording from line in (part of a recent firmware upgrade, so
not
> > listed in their product pdf). It is more appealing in some
respects
> > than the JB3 in that they apparently use an open firmware
> > system ( at least some of their code is available on the web
> > site), encourage programmers and developers, and are
> > responsive to user feedback . Perhaps this is worth a look.=20
They
> > are close to implementing timed recording from the built-in
FM
> > tuner. With user interest it would be only a moderate step to
> > implement timed recording from the line-in.
> >
> > If you can accept MP3 only HD recording, there are several
other
> > options (e.g., Archos).
> >
> > Bill Rainey
> >
> > --- In "Graham M
Smith"
> > <> wrote:
> > > Raimund,
> > >
> > > Thanks again, the MP3 option sounds good. I had not
realised
> > there was a
> > > limit to the size of a WAV file.
> > >
> > > Graham
> > >
> > > > -----Original Message-----
> > > > From:
> > > > Sent: 24 March 2004 20:01
> > > > To:
> > > > Subject: RE: [Nature Recordists] Alternatives to Minidiscs
- or
> > bats
> > > > again
> > > >
> > > >
> > > > Graham,
> > > >
> > > > as Marty already explained, even a 20 GB disk has a
huge
> > capacity. The
> > > > recording time of 2000 minutes (at 44.1 kHz, stereo)
would
> > > > further increase if you
> > > > used only one channel and a sample rate of only 22 kHz.
> > Then you would get
> > > > 8000 minutes (133 hours). However, you should note that
a
> > single
> > > > .WAV file can
> > > > hold only 2 GB of data.
> > > >
> > > > As discussed earlier, it would also be justified to use the
> > > > compressed .MP3
> > > > format for recording bat detector output signals. That
would
> > > > further increase
> > > > the recording time. For instance, a moderate 5:1
> > compression (at 64kbps)
> > > > would provide 660 hours (4 weeks!).
> > > >
> > > > Raimund
> > > >
> > > >
> > > > > Raimund,
> > > > >
> > > > > Thanks, Have you any idea of how many hours of
> > uncompressed WAV
> > > > file, the
> > > > > 20gb and 40gb models will hold - I don't seem able to
find
> > that
> > > > on the web
> > > > > site.
> > > > >
> > > > > Graham
> > > > >
> > > > > > -----Original Message-----
> > > > > > From:
> > > > > > Sent: 24 March 2004 16:18
> > > > > > To:
> > > > > > Subject: Re: [Nature Recordists] Alternatives to
Minidiscs
> > - or bats
> > > > > > again
> > > > > >
> > > > > >
> > > > > > Graham,
> > > > > >
> > > > > > The 'NOMAD Jukebox 3' by Creative Labs Inc. has a
line
> > in connector,
> > > > > > FireWire interface and also offers uncompressed
.wav
> > file recording:
> > > > > >
> > > > > > http://www.nomadworld.com/products/Jukebox3
> > > > > >
> > > > > > Regards,
> > > > > > Raimund
> > > > > >
> > > > > >
> > > > > > > Some may remember the earlier thread on rcording
> > bats, where my
> > > > > > recording
> > > > > > > problems looked as if they would be solved by the
new
> > Hi-MD
> > > > recorders,
> > > > > > > However, we need these (20 in all) in April/early May
> > and it seems
> > > > > that
> > > > > > > the
> > > > > > > release has been delayed until June.
> > > > > > >
> > > > > > > So rather annoyingingly, I am going to have to buy
an
> > alternative.
> > > > > > >
> > > > > > > Is any one aware of which MP3 juke box type
devices
> > have a line in,
> > > > > and
> > > > > > > will
> > > > > > > record as wve files, the output from the bat
detectors.
> > > > > > >
> > > > > > > Just so I can have this an option as I look at the
> > alternatives.
> > > > > > >
> > > > > > > Many thanks,
> > > > > > >
> > > > > > > Graahm S
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > > "Microphones are not ears,
> > > > > > > Loudspeakers are not birds,
> > > > > > > A listening room is not nature."
> > > > > > > Klas Strandberg
> > > > > > > Yahoo! Groups Links
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > >
> > > > > > --
> > > > > > +++ NEU bei GMX und erstmalig in Deutschland:
> > T=DCV-gepr=FCfter
> > > > > > Virenschutz +++
> > > > > > 100% Virenerkennung nach Wildlist. Infos:
> > > > http://www.gmx.net/virenschutz
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > "Microphones are not ears,
> > > > > > Loudspeakers are not birds,
> > > > > > A listening room is not nature."
> > > > > > Klas Strandberg
> > > > > > Yahoo! Groups Links
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > __________ NOD32 1.691 (20040324) Information
> > __________
> > > > > >
> > > > > > This message was checked by NOD32 antivirus
system.
> > > > > > http://www.nod32.com
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > > >
> > > > > "Microphones are not ears,
> > > > > Loudspeakers are not birds,
> > > > > A listening room is not nature."
> > > > > Klas Strandberg
> > > > > Yahoo! Groups Links
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > >
> > > > --
> > > > +++ NEU bei GMX und erstmalig in Deutschland:
> > T=DCV-gepr=FCfter
> > > > Virenschutz +++
> > > > 100% Virenerkennung nach Wildlist. Infos:
> > http://www.gmx.net/virenschutz
> > > >
> > > >
> > > >
> > > >
> > > > "Microphones are not ears,
> > > > Loudspeakers are not birds,
> > > > A listening room is not nature."
> > > > Klas Strandberg
> > > > Yahoo! Groups Links
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > __________ NOD32 1.692 (20040324) Information
> > __________
> > > >
> > > > This message was checked by NOD32 antivirus system.
> > > > http://www.nod32.com
> > > >
> > > >
> >
> >
> >
> > "Microphones are not ears,
> > Loudspeakers are not birds,
> > A listening room is not nature."
> > Klas Strandberg
> > Yahoo! Groups Links
> >
> >
> >
> >=20
> >
>
> --
> +++ NEU bei GMX und erstmalig in Deutschland:
T=DCV-gepr=FCfter Virenschutz +++
> 100% Virenerkennung nach Wildlist. Infos:
http://www.gmx.net/virenschutz
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