Hi Thomas--
You're welcome. "Hot" can take-over the brain.
I'll have to look at where you are located.
A FAQ is long overdue. I've started making a
community FAQ document that I'll soon post a link
to that list users can make additions to. Rob D.
=3D =3D =3D =3D
At 3:26 PM +0000 6/16/10, Bocianowski Thomas wrote:
>Hi Rob,
>
>Thanks a lot for the clear explanation. That
>will make my life easier, as for now the
>situation is resumed to live with the internal
>mics (at the right gain level) or eventually
>later purchase better external mic with low self
>noise :o)
>
>I wonder if it would be possible to gather such
>advices in a FAQ but maybe it is already
>existing somewhere.
>
>Best regards from the Sultanate of Oman (Boiling hot)
>
>Thomas
>
>________________________________
>De : Rob Danielson <<type%40uwm.edu>>
>=C3=80 :
><naturerecordists%40yahoogroups.com>=
m
>Envoy=C3=A9 le : Mer 16 juin 2010, 0h 25min 58s
>Objet : Re: [Nature Recordists] Recording hints
>
>At 6:17 PM +0000 6/15/10, Bocianowski Thomas wrote:
>> Hi All,
>>
>>I have recently started to record sounds around, first using a voice
>>recorder, then I decided my self for a Marantz PMD 620.
>>By now I am recording at a lower level of gain to limit the unwanted nois=
e.
>>
>>In fact if possible I'd like to have some advice on how to record
>>properly, I searched the archive but couldnt find resources on that
>>particular recorder, but I guess there are general rules that could
>>apply.
>>
>>Shall I use only PCM or MP3 can be sufficient ?
>>Is there any particular software that can help in removing
>>hiss/unwanted noise ?
>>
>>Thanks,
>>
>>Thomas
>
>=3D =3D =3D =3D
>
>Hi Thomas.
>
>Thanks for scanning the archives first!
>
>Even though it has a profound impact on "quality," I didn't fully
>understand the sources of noise in recordings for many years. Its not
>a particularly complex phenomenon-- just not what it first seems to
>be.
>
>In the great majority of instances, the source of noise one hears in
>recordings is the "self-noise" of the microphones used. When you
>increase the record gain in the recorder, it seems like this
>adjustment is adding hiss or noise, but its really just the signal
>from the microphones being amplified and becoming more audible along
>with the audio signal subject matter.
>
>The ratio of the mic "self-noise" to the audio signal is pretty much
>a constant. If you use a lot of gain the combined self-noise and
>audio signal has more "level" or "saturation" on the recording
>medium. If you use a small amount of gain, the combined self-noise
>and audio signal has little "level" or "saturation" on the recording
>medium. To hear the high level recording at a comfortable level, you
>might have to turn the playback volume down. Conversely, to hear the
>2nd recording at a comfortable level, you might have to turn the
>playback volume up. As long as you don't turn the record level in
>the field so high that the audio signal overloads the record circuit
>and distorts, the amount of hiss or noise in the audio played back in
>both recordings will be very close to the same. There are two more
>common exceptions. The mic preamplifier circuits in lower cost
>recorders can add some more noise at the highest settings and if the
>signal is recorded at a very very low level, there can be additional
>quantizing noise. A good rule of thumb is to set the record level so
>that the "peaks" of the bird calls, music, voice, etc. extend into
>the range between -25 and -12 dB on the record scale. Feel free to
>use whatever record gain is necessary to achieve this level without
>significant quality loss. There are other caveats, but these
>principles are good one's to "lock-in to one's memory" before
>exploring them and becoming confused again.
>
>As far as tricks to achieve very low noise recordings, none are as a
>effective as using mics with very low self-noise. As a guide, the
>built-in mics in your PMD 620 probably have self-noise in the range
>of 25dB(A) to 32dB(A). Mics that folks use to reduce noise to the
>lowest levels have about 1/4 to 1/6 as much noise with self-noise
>ratings in the 5-10 dB(A) range. As a result, one has no trouble
>finding posts in the archive with the terms, "low self-noise mic
>cost" in common. ;-) Rob D.
>
>--
>
>
>
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