[microsound] Zoom H4 tech query -- anybody else?

[Ken Restivo]

I think the best people to ask would be Zoom's tech support. This looks like a bug.

I'd be curious how much RAM the H4 has. I'd also be curious if the period of the noise changes with the bit depth and sample rate. I'd also be curious if it does this while in USB mode, or only when recording to an SD device.

My initial hunch would be that the Zoom "saves" or buffers the audio to RAM initially, and then writes it in bulk to the flash device. If so, that noise that you are seeing noise might be caused by it writing to the flash device.

-ken
-------------
On Mon, Apr 06, 2009 at 10:19:23AM -0400, Michael Palace wrote:
> I have a zoom h4 and noticed this problem as well.  I noticed it when I 
> was doing long recordings in the Brazilian Atlantic Forest.  I would set 
> the recorder down and go do fieldwork and come back a few hours later.  
> There was absolutely no electrical interference.  I thought it was the 
> card.  I was recording at 44 kHz and 16 bit. 
> 
> Here is a view of the wavefile.
> 
> http://www.csrc.sr.unh.edu/~palace/10010010/h4_low_sound.jpg
> 
> Mike Palace
> 
> 
> John Hudak wrote:
> > hi john,
> >
> > i don't have a zoom h4, but i had a marantz pmd660 with which i used a 
> > compact flash midi drive that caused a high pitched whine.  see if you 
> > still get the sound with a plain compact flash.  the mini drives have 
> > more memory, but as far as i have heard, have the tiny whine of a tiny 
> > drive.
> >
> > i hope this perhaps helps.
> >
> > best,
> > john
> >
> > On Sun, Apr 5, 2009 at 9:58 PM, John Hopkins <jhopkins at tech-no-mad.net 
> > <mailto:jhopkins at tech-no-mad.net>> wrote:
> >
> >     Hey folks -- I've been using a zoom H4 for a couple years now, and
> >     have
> >     been suspicious how a non-mechanical recording device -- in a really
> >     quiet place (for example the Sonoran desert of western Arizona) -- and
> >     the wave form of a short recording of a passel of birds in a mesquite
> >     tree at dusk shows a cyclic 3-sec repeating pattern which seems to be
> >     very low frequency something (sorry, don't have a spectral freq
> >     analyzer
> >     on my machine).  I uploaded a screen shot of the waveform and a
> >     wav copy
> >     of the file -- any feedback?  Has anyone else experienced this
> >     with the
> >     H4?  I've seen it before on the files when recording in really quiet
> >     places, and of course I suppose the best solution is probably a few
> >     thousands spent in better field recording equipment, to be sure,
> >     but...
> >      what could be the cause?     In this instance I was not hand holding
> >     it, it was on the ground in a stable place, and essentially no wind.
> >     There is also a higher-pitched whine as well, faugh!
> >
> >     the sound file: http://neoscenes.net/09-03-092_birds.wav and a screen
> >     shot of the file in Peak showing the approximately 3-second repeating
> >     patterns http://neoscenes.net/09-03-092_birds.jpg
> >
> >     cheers,
> >     John
> >
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> >
> >
> >
> >
> > -- 
> > http://www.johnhudak.net
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