Thanks Bill, always accurate!
You write:
>This means the LS-11 preamp is 3dBu quieter than the LS-7 under
>these test conditions. That's a difference that you will be able to
>hear in your recordings, but
1: only if you use an external mic that has very low self noise, and
2: when recording in a space that has a very quiet ambience.
and, I would add, most important:
3: if the external microphone has such a low output voltage / Pa that
it=B4s signal needs to be amplified a lot by the recorder mic input amplifi=
er.
On the other hand, which is what I suggest, is that there are no such
low output mikes on the market today. Even a small one dollar
electret will have an output which is high enough to run over the
noise of a 110-115 dBu recorder noise.
Some history to spread light on the mic preamp noise as a "holy cow",
when 1 or 2 db mattered.
In 1975, a typical recording birder in Sweden would buy a Beyer ME80
to put in his parabol. He chose it because it had a flat freq.
response, which he was told was "the best". Probably he would have
preferred to buy a MKH, but he could not afford it. Instead he spent
the rest of his money on a used Nagra III.
But the output voltage of ME80 was only 1,5 mV/Pa, which meant that
the Nagra would have to amplify the signal about 1000 times (60dB) to
feed the Nagra recording head enough to saturate the tape. Not even
the Nagra III input was good enough to amplify 60 dB without adding
"hiss". So, if you wanted "hiss.free" recordings, you had to use a
big parabol and the bird had to be really close.
Sten Wahlstr=F6m, at the time, found that Sennheiser MD21 gave almost 3
mV/ Pa and that there was a company in Stockholm making a special
transformer for it. Using this transformer with the most low noise
transistor of the time, 1N930, he succeeded in making a preamp that
performed much better than even the Nagra III.
Those were the times when preamp noise was very important! It was
"all" as a matter of facts and the biggest challenge for
naturerecordists struggling with noise / hiss!
But today is different. Even in the 90-th, you could buy a cheap
electret which performed almost as good - and better - than the best
condensor microphones 10 years earlier! Primo made a 10 mm capsule
called EM60, which - connected to a Nagra III input - provided such a
high output that what you heard was the mic noise, not the Nagra noise.
To all people asking what recorder to use - go on the price, weight,
menus, battery life - buy a recorder that you like to use - don't
sacrifice any such "qualities" for some 3 dBu less input noise.
Klas.
At 06:35 2011-06-04, you wrote:
>Peter,
>
>The Avisoft web pages include a tutorial that helps explain what the
>recorder preamp noise specifications mean.
>http://www.avisoft.com/tutorial_mic_recorder.htm
>
>Consider these specifications only:
>Olympus LS-11 -122dBu unweighted
>Olympus LS-7 -118dBu unweighted
>
>This means the LS-11 preamp is 3dBu quieter than the LS-7 under
>these test conditions. That's a difference that you will be able to
>hear in your recordings, but only if you use an external mic that
>has very low self noise, and when recording in a space that has a
>very quiet ambience. If you're recording louder sounds, or using a
>mic with more self noise, the recorder self noise will be masked
>under most circumstances.
>
>Results from pocket recorders almost always can be improved by the
>use of a good quality external microphone. For example, Klas
>Strandberg has introduced a model designed for the Olympus LS-xx
>models. http://www.telinga.com/ls10.htm Unfortunately, you'll need
>to spend quite a bit more than the cost of the recorder on such a micropho=
ne.
>
>For the record, neither the LS-11 nor the LS-7 is considered a good
>solution by itself as a primary field recorder. These are
>pocket-size models that best serve as casual recorders note-taking
>machines. They can be pressed into service as a primary recorder
>when you want to travel light, or need a less obtrusive recording kit.
>
>If you're looking to make very high quality recordings, none of the
>pocket recorders is a good solution. In the less-than-$1000 range,
>take a look at the Fostex FR-2LE recorder. And expect to pay an
>additional $1000 to $2000 for microphones, cables, wind screens and
>mic stands. Professional gear costs a lot, but delivers superior
>results, increased durability, and improved ease of use under
>difficult conditions.
>
>Does this mean you can't make an excellent recording with an
>inexpensive pocket recorder? No, but the conditions have to be just right=
.
>
>Many vendors of recording equipment will allow you to try out a
>recorder for a few days to see if meets your requirements. Try
>several models to see which one works best for you.
>
>--oryoki
>
>
>
>
>------------------------------------
>
>"While a picture is worth a thousand words, a
>sound is worth a thousand pictures." R. Murray Schafer via Bernie Krause.
>
>Yahoo! Groups Links
>
>
>
Telinga Microphones, Botarbo,
S-748 96 Tobo, Sweden.
Phone & fax int + 295 310 01
email:
website: www.telinga.com
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