I was sure it wasn't environmental noise, but using David's Mute and Solo A=
udacity trick to quickly flip between tracks to compare the Mt Hotham recor=
ding with the "silent" recording, I can plainly hear that they sound differ=
ent. Thanks for that one, David, I've been fiddling with those controls but=
couldn't work out a way to flip it instantly.
I'm still not convinced it's wind in the trees, as I can hear the same soun=
d in a recording from the previous day, and my notes say "still" for the wi=
nd. I'm beginning to see the value of keeping good notes now. I think it's =
too constant to be leaves, although perhaps there were a few puffs of wind =
occasionally. That means it must be a watercourse. There was a creek a km o=
r so down the gully, odd that I don't remember the noise. Perhaps, as you s=
ay, I just filtered it out.
Apologies to those who suggested this in the first place, I didn't believe =
you.
Recordings taken nearby the same day with the ME66 were "hiss" free so I as=
sumed it was the equipment, but perhaps I just happened not to point it in =
the right direction to pick it up.
I wish I could go back to check, but that won't be possible for two years.
The best I can do to reassure myself in the meantime is try to get a better=
"silent" recording. The one I got inside the cushions is a bit suspect, th=
ere are sounds from outside in it. I'm wondering if I'd get a clean recordi=
ng if I put the recorder in a bag and buried it for a minute or so.
Now I need to listen carefully to the untouched recording a few times to tr=
y to hear that water.
Peter Shute
From: O=
n Behalf Of chrishails50
Sent: Sunday, 12 February 2012 6:02 PM
To:
Subject: [Nature Recordists] Re: M10 noise removal, was Sony PCM-M10 vs Zoo=
m H4n best for outdoor
Peter, I too use the M10 quite a lot as a pocket carry around. I can hear s=
elf-noise from it in very quite moments - which for me is deep in Swiss for=
ests after midnight. But even then long distance aircraft rumble and insect=
noise is still there. As others have stated on your soundcloud piece (whic=
h I liked by the way), to my ears a lot of the hiss you are hearing is natu=
ral - wind, insects, leaves rattling etc. Stuff our brain filters out when =
in situ, but is really apparent once you get home and listen to your record=
ing in isolation.
You said you did not want to carry a tripod to get the machine away from tr=
ees - I use a mini-tripod of the "gorilla" type with my M10 - cheap portabl=
e and flexible:
http://www.ebay.com.au/sch/i.html?_nkw=3Dgorilla+grip+tripod
And as many have said getting close to the sound source and a good strong s=
ignal gives by far the best result, if you halve the distance you double th=
e signal.
Good luck.
Chris
http://www.wildechoes.org
--- In <naturerecordists%40yahoogrou=
ps.com>, Peter Shute <> wrote:
>
> I've posted a "noise only" sample to Soundcloud. I'll stop calling it his=
s for now:
> http://soundcloud.com/petershute/120202-01pcmm10silence
>
> I haven't had time to take the recorder anywhere truly quiet to record a =
better sample, so this was done at home with doors and windows closed, sand=
wiched between two cushions with a blanket over the top. I'm sure there's p=
lenty of sound from outside in the recording, but at least I've reduced it.
>
> The spectrum analysis in Audacity says it's all below 9kHz, with a peak b=
elow 500Hz which might be noise from outside that I couldn't block. Very in=
terested to hear opinions about the nature of the noise.
>
> I also did a similar recording with the level turned right down. There wa=
s similar noise, but of much, much lower volume. I assume this proves it's =
not preamp noise?
>
> I've also uploaded the latest attempt at reducing the noise:
> http://soundcloud.com/petershute/111229-03nr5
>
> With 30dB reduction, I've not been very gentle with the recording, so I'm=
interested to know what others find wrong with it. The untouched recording=
for comparison is at:
> http://soundcloud.com/petershute/111229-03brandyck
>
> Concerning my hearing, I took my audiologist's word that I've got little =
hearing above 8kHz, but I played with tone generation in audacity just now,=
and I can hear up to 15kHz, but I can't really quantify how well except th=
at it's nowhere near as good as at 8. I note that she didn't test above 8.
>
> Perhaps I'm playing it back louder than she would have in a test too. Int=
erestingly, at a level at which I can clearly hear 15000Hz, 15100 is just n=
ot there. I'm probably running into equipment limitations too.
>
> Peter Shute
>
> ________________________________
> From: <naturerecordists%40yahoogro=
ups.com> <naturerecordists%40yahoog=
roups.com>] On Behalf Of Avocet
> Sent: Saturday, 11 February 2012 10:19 AM
> To: <naturerecordists%40yahoogroup=
s.com>
> Subject: Re: [Nature Recordists] Re: M10 noise removal, was Sony PCM-M10 =
vs Zoom H4n best for outdoor
>
>
>
> > Peter mentioned on his Soundcloud example, the hiss he was concerned
> > with was mostly below 5kHz. To my own ears the problematic
> > microphone hiss noise in that recording was most prominent from 8 to
> > 10 kHz.
>
> John,
>
> In my previous email I indirectly defined "hiss" in my HPF
> specification as being 4KHz and above, in other words the top two
> octaves. "Thermal" (root f) mic hiss goes right up as high as you
> record and to my ears anyway sounds different. The bottom end noise
> (the bottom four octaves?) is "rumble" but I can't think of a
> universal name for mid range noise except "mid range noise". :-)
>
> I'll back you up on annoying hiss being 8 to 10 Khz and this is
> recognised in the "468" weighting for background noise measurements.
>
> BTW at my fairly advanced age of 71 my own frequency response still
> goes from 10Hz to 12KHz which is not bad. That's still over 10
> octaves.
>
> David
>
> David Brinicombe
> North Devon, UK
> Cogito cogito ergo cogito sum - Ambrose Bierce
>
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