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Re: LS-10 vs 702, ambience

Subject: Re: LS-10 vs 702, ambience
From: "vickipowys" vpowys
Date: Fri Aug 14, 2009 2:15 pm ((PDT))
Raimund,

Interesting what you say (below).

But how do I know that the LS-10 is not attenuating the signal when I  
am using LOW SENSE?  (or conversely that it is amplifying it when  
using HIGH SENSE?)

cheers,

Vicki


On 14/08/2009, at 5:13 PM, Raimund Specht wrote:

> Hi Vicky,
>
> So, it seems that the higher self noise level at SENSE LOW and 16  
> bit is still 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 voltage divider) that attenuates the output signal  
> of the first preamplifier stage 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 and 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
>>>
>>>
>>>
>>
>
>
>
>
> ------------------------------------
>
> "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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