2
Date: Thu Jan 2, 2014 8:28 pm ((PST))
Eric;
It is most likely that you overloaded either the mic's internal preamp or t=
he input of the outboard mic preamp or both.
Depending on the circuit topology and supply rails of the outboard mic prea=
mp, one can overload the input stage.
But it is more likely that the mic capsule or its internal preamp got overl=
oaded.
That is why it looks like you have not exceeded the 0 dB record level, but =
you still have distortion.
Moving the mic away from the sound source keeps it from being overloaded.=
=C2=A0
I have had personal experience with this type of recording, e.g., bells, go=
ngs and carillons and gamelan. Often one needs to engage the mic's internal=
pad (10 or 20 dB), then use the lowest gain setting for the outboard mic p=
reamp. Judicious placement of the mic is also of paramount importance. Alwa=
ys use your ears, with a good pair of closed-back headphones, to setup the =
recording before hitting record.
- Greg=C2=A0
From: Eric Fassbender <>
To:
Sent: Thursday, January 2, 2014 9:43 PM
Subject: Re: [Nature Recordists] Distortions when recording tibetan singing=
bowls/gongs
=C2=A0
Hi all and sorry for the very late response, I just haven't had time to ans=
wer.
So here is a sample of the recording:=C2=A0https://soundcloud.com/australia=
nnaturesounds/gong-with-distortions
The photo shows the spectral analysis in which you can see the distortions.=
Note that at the loudest point the recording is still at -7.6 dB so it can=
't be the volume.
Also, I should mention that this is a sample of a gong and not a tibetan bo=
wl as I originally wrote. The reason I chose this sample is because the eff=
ect is much more prominent, however, I have had the same issue with singing=
bowls.
To answer some of the other questions, it was not the attenuation that was =
the problem. But moving further away from the gong and then increasing the =
levels in post worked well. So it could be that the max SPL was reached but=
I somehow doubt that because it wasn't really that loud.
Regards,
Eric
Please consider donating to our=C2=A0fundraising campaign to extend nationa=
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On 27/10/2013, at 11:14 AM, Aaron L. Rosenblum <> wrote=
:
=C2=A0
>
>
>Has anyone experienced ultrasound distortion with insect recordings? It se=
ems perfectly possible, and this summer I made a recording of a field at su=
nset that was positively alive with crickets and other buzzy things. The re=
cordings have a loud buzz that was not audible IRL and doesn't seem to have=
come from any nearby equipment (there was a house A/C unit in the distance=
, and it's audible as you would expect). There seemed to be a certain amoun=
t of axis sensitivity to the distortion. I puzzled over it for a while and =
wondered what kind of electromagnetic potential insects have. But ultrasoun=
d having an effect on the mics sounds much more likely.=C2=A0
>
>
>Also, to the original post, I have certainly experienced clipping or disto=
rtion with loud signals while recording with my Tascam set in high sensitiv=
ity mode (of three modes), with the more granular level control set pretty =
low to avoid (so I thought) clipping. The solution for me was to change to =
a lower sensitivity setting (the -20dB pad in your case, I guess) and then =
modulate the more granular level setting from there as need be.=C2=A0
>
>
>Aaron
>=C2=A0
>I once spent two months recording Tibetans in the Zanskar Valley and am no=
w=C2=A0
>>involved in ultrasound with bat recording. My guess is that it is ultraso=
und=C2=A0
>>distortion in the mic or input stage from the percussive instruments. Thi=
s=C2=A0
>>is not included in the spec of most mics.=C2=A0
>>David Brinicombe=C2=A0
>
>
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