At 11:29 AM -0700 3/21/09, Dan Dugan wrote:
>David Michael, you wrote,
>
>> I suppose the main improvement for me was the gain. It may be true,
>> that given enough gain, the FR2LE and the MixPre have comparable
>> responses, but the FR2LE has very low gain on its own, at least when
>> using my MKH30/40 combo (others with similar experiences?).
>
>My experience (brief) was that the gain was just enough when the trims
>were all the way up.
>
>> The other serious problem I had with the FR2LE was that if I cranked
>> up the gain high enough to get a sufficiently hot signal in quiet
>> situations, the unit induced a high-pitched, broad-banded hiss
>> (especially from the trims turned most of the way up). I have
>> eliminated this hiss by keeping the FR2LE at low gain on the trims
>> and input gain knob and having the MixPre heat up the signal coming
>> in.
>
>This is the experience most people have. When you turn up the trims,
>as the get close to max you hear a sudden increase of gain and of
>course noise with it. But then if you turn the headphones down the
>same amount you turned the trimmers up... It's all a matter of signal-
>to-noise.
>
>> So a MixPre giving nice gain to an FR2LE that is set to a low to
>> moderate gain has really improved the overall recording quality.
>
>That is the 64-dollar question--whether that is true or not. No
>question that you can get higher gains with the MixPre-FR2LE
>combination.
>
>> To be really fair about this discussion, I should do some controlled
>> experiments, perhaps in the backyard one morning. Do you perhaps
>> have a schedule of recordings or experiments I should try... maybe
>> specifically concerning gain.
>
>Sure. You could do it in a quiet room indoors. We want to compare the
>FR2LE mic inputs with trimmers at max with whatever control settings
>of the MixPre and line inputs matches that sensitivity. Since you're
>recording 2-channel, you'll have to estimate the MixPre gains when you
>make the recording, and then tweak the levels in post to match. I
>suggest setting the mics on a stand so they don't move, and setting a
>A-440 guitar tuner or other tone source a few feet away in the room.
>Then in post you can use a spectrum analyzer to match the tone levels,
>and 1) observe the differences between the room tone curves and 2)
>make a level-matched A/B comparison file to share.
>
>If you don't move the mics or tone source between the two recordings,
>and there are no loud sounds leaking in, that should work. Put
>yourself remote from the test setup, because moving your body in the
>room will change the level of the tone.
>
>If you can't do the post level-matching part, just make the recordings
>and Rob or I can do the matching and comparison. This experiment will
>be very helpful to the group.
>
>-Dan
>
Five more factors that might improve the chances of making a good compariso=
n:
(1) Turn off everything you can that is in the same or nearby room--
computers, fans, heaters, fish tanks, even the refrigerator if its
anywhere near the room including directly above or below.
(2) Run all gear on DC or fresh batteries.
(3) What ever you use for the "signal" e.g. clock, tone generator--
make sure the sound generated is absolutely consistent and not very
loud in relation to the room/background ambience. If the sound source
is too loud, it will make it harder to evaluate the noise differences.
(4) Take long takes of each recording-- at least 10 minutes each so
you can choose segments with minimal traffic for better-matched
background sounds. If you live near streets, it can be better to do
it in the "wee" hours.
(5) If you are using an M-S Pair, make sure the matrix settings you
use in post are identical or, as Dan suggested, you can post the raw
files one of us can match playback levels. Rob D.
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