At 8:48 PM -0800 11/14/09, Dan Dugan wrote:
>
>
> >> Last weekend I did my first recording with my shoulder-mounted
>>> Telinga EM-23 mics into my LS-10. Gain was high-5 or 6. The
>>> recording was noticeably noisier than the same mics with a Sharp MD-
>>> MS722, gain L-15. I was planning to replace our Sharp MDs with
>>> LS-10s, but now I'm not so sure. I'll try low gain and a higher pot
>>> setting before I decide.
>
>Today I did a series of experiments around my LS-10. I set up a
>ticking clock in a quiet room, and matched levels with a 1 KHz tone
>from a speaker with a probe to position it a fixed distance from the
>mic.
>
>Telinga EM-23s into my old Sharp MD-MS722 (gain L/15) were 2 dBA
>quieter than the same mics into the LS-10 (gain high/5.5). I could
>see the low-frequency broad-band noise that has been mentioned here
>extended up beyond 1 KHz.
>
>EM-23s into the LS-10 with gain low/10 were 1 dBA quieter than the
>high/5.5 setting, and 1 dBA noisier than the Sharp, after boosting
>the gain 12 dB in post.
>
>I tried using a Sharp MD-MT90 as a preamp into the LS-10 line input.
>The noise level measured the same as a Sharp MD recorder alone, but
>it didn't sound as good because the LS-10 still had rising
>low-frequency noise in this configuration.
Hi Dan--
So, for the above, the loudest noise was from the EM-23 -> MT90 combo
but low Hz noise from the LS-10's _line input_ was also audible? Does
this suggest the noise could be created in the A-D or somehow
upstream from both the mic and line inputs?
When I tested a MT-90 MD with NT1-A's a few years back, I got a
pretty sizeable noise bump compared to a Hi-MD recorder:
https://pantherfile.uwm.edu/type/www/audio-art-tech-gallery/pages/SD722_Rol=
ls_HiMD_D7_MD_TRVmov.html
The NT1-A's, being about 9 dB(A) quieter, reveal more of the pre
differences.
I agree its not encouraging that you can hear the input noise of the
LS-10 with EM-23's, but its even more surprising that the L-10's
circuit design would add noise to the line input. It would be
telling to see if you can repeat/exaggerate this with combos using
quieter mics like:
AT-3203 -> 744T
AT-30203 -> Port Phantom Supply -> LS-10 Mic Input
AT-3203 -> MP2 -> LS-10 Line Input
AT-30203 -> Port Phantom Supply -> Better of the MD recorders Mic Input
AT-30203 -> MP2 -> Better of the MD recorders Line Input
>It's remarkable that a cheap 1998 recorder has a better
>signal-to-noise ratio than the latest thing. Too bad it won't record
>PCM files (ATRAC only).
It is certainly reasonable for one to expect that mic self-noise as
high as the EM-23's [14 dB(A)] would be high enough to mask all
input pre noise in all recorders made after 2004, when Hi-MD was
released.
Maybe the manufacturers aren't hearing enough noise from recordists. Rob D.
>Recording with the LS-10's own mics resulted in a 10 dB higher noise level=
.
>
>-Dan Dugan
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