Hi Max--
Interesting test. Thanks for conducting it!
As you and I have started discussing off-list, the most significant
difference between the two test recordings is a warm airyness (from
200-2000Hz) that is in the FR2's recording that is not in the
FR2-LE's recording.
To view the test movie in your web browser: http://tinyurl.com/nbnvf6 (1.5 =
mb)
to download http://tinyurl.com/neea97 and view with QuickTime (1.5 mb)
Audio Technica AT-3032 mics were used; max gain and no trim used in
both recorders. The FR2 sample comes first. Playback volume is
matched in post.
(If anyone on PC has success viewing the downloaded movie with an
application other than QT, could you contact me off list?)
As we are reasonably sure that the added sound is not
"environmental"-- that is-- NOT being created in the space by
something like air-handling equipment, then its likely to be FR2 pre
noise occurring low in the spectrum. The additional noise would be
consistent with John's input noise measurements-122 dBU (A) for the
FR2 and -129 dBu (A) for the Fr2-LE. Though noise this low into the
audio spectrum is fairly unusual and it is surprising to me that no
one has pointed it out in the FR2 before, we also observed a similar
problem with the pre in the Olympus LS-10.
I bet we'll come across some evidence generated by other recordist
that will either make us 99% confident about this or we'll discover
some factors we overlooked. But, if the test and assessment _are_
on-target, and one is using the recorder under high gain situations
with the 3032 mics [or those with self-noise of around 14dB(A) or
lower], the FR2-LE's mic preamp should render considerably greater
clarity in the lower mid range. This part of the spectrum can play a
large role in creating important spatial cues in recordings where a
sense of "ambience" is desired.
The noise in the highest octaves is so matched, audibly, that I
suspect we're hearing the self-noise of the AT-3032 mics. There could
be a tiny bit better HF response in the FR2-LE. The FR2 seems to have
about 6 dB less gain for recordists to work with.
Quite often, recorder manufacturers claim they've made improvements
in noise performance in newer models but we have a hard time
confirming this in the field. In this case, even though Fostex didn't
seem to make such an announcement, its looking like there's a pretty
good chance they addressed some mic preamp noise issues with the FR2
when designing the FR2-LE. A beauty of a list like this is we're more
likely to hear about it if another recordist comes across additional
evidence.
The test also points out that its probably safer to operate on DC
power for critical recordings rather than assume the AC power unit
won't contribute some noise.
Rob D.
=3D =3D =3D =3D
At 11:20 AM +0000 8/3/09, Max Catterwell wrote:
>
>Hi again all!
>OK, I've just posted another two clips that Rob has graciously
>agreed to analyse for me. The FR2 clip on this set doesn't have the
>PS hum! Also, the electric clock was turned off.
>Max
>
>--- In
><naturerecordists%40yahoogroups.com>=
m,
>"Max Catterwell" <> wrote:
>>
>> Hi Rob!
>> OK, I have posted the two requested clips. These are in a folder I
>>created called FR2 and FR2-LE clips by Max. They were both at 16/48
>>with all gain at maximum, and are the 'cleanest' I could find. One
>>thing I missed was an electric clock about six feet away from the
>>mics. Bye the way, in case it's relevant, the mics are set in a
>>wooden Olsen type barrier array at the moment; I'm assuming this is
>>not of concern.
>> I look forward to any comments or analysis with great interest,
>>even if it turns out to be what I don't want to hear!
>> All the best
>> Max
>>
>
>
>
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