Rob,
you wrote:
> Before we can reach the conclusion. "that the higher self noise level
> at SENSE LOW and 16 bit is still sufficiently low for these
> microphones," I think Vicki would have to use the ideal record gain
> settings for the LS-10 and make recordings in a quiet room using both
> the SASS [10 dB(A) self noise] and her Telinga [higher self-noise].
> If the LS-10's pre is sufficiently quiet, there should be a very
> audible noise jump when going from SASS to Telinga. Might be wise to
> include other mics in the test too.
Problem is, Rob, that I cannot use the SASS set up with the LS-10,
due to the mics requiring phantom power. I guess what I was
originally trying to show was a. that the LS-10 COULD pick up low
rumbles of thunder (despite predictions that it could not), and b.
that the Telinga stereo mic (which can only be used with the LS-10)
made a very acceptable low-noise and highly sensitive unit for
lightweight recording expeditions.
My personal preference is for the SASS and SD702 which is a really
lovely, extremely quiet set up, and the precision of directional
information when listening through headphones is what I love the most
about it. I could not get that same amount of directional
information from the Telinga (based on the entire clips that I made,
not necessarily shown in the samples I posted).
The Telinga mic has a 'brighter' sound than the SASS-702. Klas
described the latter as 'muffled' but in reality it isn't, to my ears
anyway. I guess it has more to do with subject matter.
It is possible that the conversion of my clips to mp3 produced some
unevenness of ambience.
I agree that the LS-10, even with optimal settings (low sense, volume
10) has more noise than the SD-702 and SASS.
When spring arrives in earnest, I will try for some 'movement' tests,
to see how the Telinga mic (coupled to LS-10) compares with SASS-702.
By the way, I didn't change any of the levels in post, for my
examples. And have been very impressed at the sensitivity of the
Telinga.
best wishes,
Vicki
On 15/08/2009, at 12:07 AM, Rob Danielson wrote:
> At 7:13 AM +0000 8/14/09, 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.
>
> Hi Raimund and Vicki--
>
> The gestalt or overall impression of the Telinga->LS-10 recordings
> made with these enlightened gain settings seems to be fine for
> Vicki's applications. One would think that the LS-10's input noise
> should be low enough for recording events like the Red Wattlebirds
> (as indicated by the ability to use the lower gain setting and
> assuming the gain levels in the RWB.LS10_TEL vs SD_SASS file was not
> appreciably changed).
>
> Before we can reach the conclusion. "that the higher self noise level
> at SENSE LOW and 16 bit is still sufficiently low for these
> microphones," I think Vicki would have to use the ideal record gain
> settings for the LS-10 and make recordings in a quiet room using both
> the SASS [10 dB(A) self noise] and her Telinga [higher self-noise].
> If the LS-10's pre is sufficiently quiet, there should be a very
> audible noise jump when going from SASS to Telinga. Might be wise to
> include other mics in the test too.
>
> Even with the mixed mic/recorder samples, when I listen to clips from
> the quieter sections of the RWB.LS10_TEL vs SD_SASS. mp3 file, I'm
> detecting what could be an increase in noise >500 Hz with the LS-10.
> There's a consistent, jumbled, uneven quality to the ambience or
> background presence in both recordings that's making the judgement
> more difficult.
>
> I don't think we have evidence that the LS-10 is a good fit for
> recording ambience in quiet locations with a rig like the MKH-10/SASS
> recording ambience as yet. Maybe, by using this ideal record gain
> setting, one can record at 24 bits and boost the results in post to
> get low(er) noise performance. I fear this technique will not be able
> to get around the LS-10's audible noise under 500Hz, but a test will
> shed more light on the possibilities.
>
> Of course, Vicki can take her SD722 into the field to record ambience
> in quiet locations with the SASS. The comparison test I'm suggesting
> would only apply to those who are looking at an LS-10 to use for
> similar situations and she might have better things to do! :-)
>
> Should you be curious about this comparison, Vicki, be sure to make
> the takes long so you can choose the quietest moment from each. Post
> the original clips, no changes applied. Rob D.
>
>
>
>>
>> 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/>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
>>> <naturerecordists%
>>> 40yahoogroups.com>
>>> 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.
>>>>
>>>>
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