At 4:42 PM +0000 2/6/09, oryoki2000 wrote:
>Leonard Lombardo, owner of Sonic Studios in Oregon USA, has reported
>self-noise test results for many portable recorders.
>
>Here is the graph of test results for the Sony PCM-D50. It shows a
>noise floor better (that is, lower) than -114 dBu when a Sonic
>Studios preamp is connected to the line input.
><http://www.sonicstudios.com/-35dbu_n.gif>http://www.sonicstudios.com/-35dbu_n.gif
>
>And here's a similar graph for the Olympus LS-10. The line input self
>noise when used with the same Sonic Studios preamp is a little noisier
>than -114 dBu.
><http://www.sonicstudios.com/-35PIPvs3SX.gif>http://www.sonicstudios.com/-35PIPvs3SX.gif
>
>Reading between the lines, as it were, these graphs show that the D50
>has a noise floor that is maybe 3 dB lower than the LS-10 under
>similar conditions. Since the nature of the dB scale is to double
>sound pressure every 6 dB, I think a 3 dB difference would be noticeable.
>
>This makes sense, since the D50 costs quite a bit more than the LS-10,
>and you expect better performance for more money.
>
>--oryoki
Hi Oryoki
I recall Vicki Powys experience with her LS-10
http://tinyurl.com/apssfa and I am reminded how input noise
measurements done on the bench do not show us the tonal character of
the noise produced by the mic pre.
Because the LS-10's pre or input noise extends much lower into the
frequency spectrum (under 500Hz), the LS-10 considerably "noisier"
than an D50.
Its important to note that this performance difference in these two
recorders is _only relevant_ when two -- not so common-- conditions
are met:
1) When high recorder pre gain is required for recording low level
sounds like ambience in quiet locations.
-and-
2) When mics with very low self-noise are used.
For general recording of robust sounds using mics with greater than
18dB(A) self-noise, the pres in most, if not all of the new, portable
card recorders will be a good match for one's needs. One can compute
this result using various charts, but the generality seems to pretty
reliable.
We would have little "concrete" to relay about the LS-10's actual
noise performance were it not for Vicki's tests. I was able to
combine hers with the testing I'd done with Hi-MD units and the fact
that the PCM D50 seems to have the same pre/noise characteristics as
the HiMD's. Rob D.
--
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