naturerecordists
[Top] [All Lists]

Re: 722 vs MixPre

Subject: Re: 722 vs MixPre
From: "Dan Dugan" dandugan_1999
Date: Sat Mar 21, 2009 11:35 am ((PDT))
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






<Prev in Thread] Current Thread [Next in Thread>
Admin

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the naturerecordists mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU