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Re: LS-10 vs 702, ambience

Subject: Re: LS-10 vs 702, ambience
From: "Raimund Specht" animalsounds
Date: Fri Aug 14, 2009 12:14 am ((PDT))
Hi Vicky,

So, it seems that the higher self noise level at SENSE LOW and 16 bit is st=
ill sufficiently low for these microphones.

I think that the problem with the lower LEVEL control settings on the LS-10=
 (and other similar recorders) is that it is a simple potentiometer (a volt=
age divider) that attenuates the output signal of the first preamplifier st=
age before the signal is further amplified and fed into the A/D converter. =
In other words, it is not appropriate to first attenuate the input signal a=
nd then amplify it again (by using the HIGH SENSE setting).

For the same reason, it is not a good idea to activate the attenuation pad =
on the microphone or the recorder while turning up the gain on the recorder=
 at the same time.

Cheers,
Raimund


Vicki Powys wrote:
>
> Raimund, Klas and all,
>
> I just compared 16 and 24 bit noise-wise in a quiet room, and I could =

> hear no difference in noise between them.  However there is a big
> difference (as mentioned previously) between high sense 2 and low
> sense 10, the latter being MUCH quieter.  I hear this difference for
> both the Telinga stereo mic and the ME66.
>
> Conclusion: I will stick with low sense 10 as my default setting for
> LS-10 with external mics, and stick with 16 bit.  Unless I am working =

> with a difficult bird with soft calls (e.g. Regent Honeyeater) where
> my default settings would be high sense 5, 16 bit.
>
> cheers,
>
> Vicki
>
> PS Klas, I am listening to all my tests through headphones.
>
>
>
>
> On 13/08/2009, at 5:22 PM, Raimund Specht wrote:
>
> > Hi Vicky,
> >
> > I can confirm your observations regarding the noise levels on the
> > different SENSE HIGH / LOW settings on the LS-10. The input noise
> > levels I measured are as follows (see also http://www.avisoft.com/
> > recordertests.htm):
> >
> > SENSE HIGH, LEVEL 10 (16 or 24 bit):
> > -122dBu(A) -119dBu(unweighted)
> >
> > SENSE HIGH, LEVEL 2 (16 or 24 bit):
> > -103dBu(A) -100dBu(unweighted)
> >
> > SENSE LOW, LEVEL 10 (24 bit):
> > -121dBu(A) -118dBu(unweighted)
> >
> > SENSE LOW, LEVEL 10 (16 bit):
> > -113dBu(A) -110dBu(unweighted)
> >
> > Note that both the SENSE HIGH, LEVEL 2 and SENSE LOW, LEVEL 10
> > settings provide the same input clipping level of -30 dBu.
> >
> > So, the bottom line is that one should better not use the SENSE
> > HIGH setting for recording louder sounds that require to turn down
> > the LEVEL setting. Instead one should use SENSE LOW, LEVEL 10 at 24 =

> > bit resolution.
> >
> > Regards,
> > Raimund
> >
> >
> >
> >
> >
> > --- In  vickipowys
> > <vickipowys@> wrote:
> >
> >> Re self noise, I don't think I AM hearing Telinga self noise.
> >> Someone contacted me off-group to query my setting of low sensitivity
> >> 10 (rather than say, high sensitivity 3).  There has been a previous
> >> discussion on naturerecordists re this.  Using add on mics, including
> >> the Telinga and a Sennheiser ME66, I find that there is more fizz
> >> when using high sensitivity.  Note that this applies to add on mics
> >> and not just the LS-10 inbuilt mics.
> >>
> >> I did a test this morning, using a metronome on front verandah rail
> >> (quiet, rural background), standing back 5 metres, with settings on
> >> LS 10 at high sens. 2.5 versus low sens. 10.  At these settings the
> >> ticking levels of the metronome matched exactly.  With both the
> >> Telinga mic (used open) and the ME66, there was more fizz with the
> >> high sensitivity setting, and when I later boosted the low sens
> >> recordings by 6 dB, the fizz level still did not equal the high sens.
> >> fizz.
> >
> >
> >
> > ------------------------------------
> >
> > "While a picture is worth a thousand words, a
> > sound is worth a thousand pictures." R. Murray Schafer via Bernie
> > Krause
> > Yahoo! Groups Links
> >
> >
> >
>








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