Bill,
Thanks for your note. I have to admit that I've never used the Nomad JB3 fo=
r
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 applicatio=
n
(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 (independ=
ently
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 o=
f
the device. That would require detailed and very special knowledge. So, eve=
n
a well-trained engineer would require several months (or even years) to
become familiar with the hard- and firmware architecture. And there would b=
e 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 recor=
ding.
Currently, the best solution for long-term monitoring of animal sounds woul=
d
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 possibl=
e
to set-up the system for a sound-activated recording mode. Special
techniques (amplitude thresholds in pre-defined frequency intervals and ent=
ropy
filters in conjunction with a pre-recording buffer) can help to reject unwa=
nted
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. 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=
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