naturerecordists
[Top] [All Lists]

Re: FR2-LE mic trim (again)

Subject: Re: FR2-LE mic trim (again)
From: "Chris Hails" chrishails50
Date: Mon Apr 28, 2008 9:55 pm ((PDT))
--- In  Rob Danielson <> wrote:
>
> I see that my dog has brought back a crow he found on the road. I
> should be joining him for lunch.
>
>

No need for that crow Rob, you teach readers of this group a huge amount.

My knowledge of audio engineering is crude at best so I can only
contribute from my experience of using the FR2LE for the best part of
a year with a Telinga stereo mic. All I know is that the trim knobs
"feel" like a pre-amp control. Like Mike and others on this group, by
setting the main record level (the big knob on the right !)to a mid
point, I found that turning the trims clockwise to about 80% of full
was the best position for maximum signal minimum noise; beyond about
80% noise was introduced (for whatever reason I do not know I just
accept it is there !). At this setting I leave them all the time, and
only adjust the record level control in the field. I have never
encountered a natural sound so loud that I could not manage it using
the main record level only (even a roe deer yelling directly into the
parabola at a distance of 50m - my post of a few weeks ago).

My problem is that the trim knobs are horrible fiddly little things
for which my stubby fingers are supremely ill-adapted. There is a
little groove on them (the trims not my fingers) which I have filled
with some white marker paint so it can be seen, trouble is there is no
reference mark on the casing to match it to (all flawed ergonomics in
an otherwise wonderful device) so it is still all a bit eye-ballish. I
find that in getting my kit ready and out of the door the trims often
get moved a bit (especially when loading the battery) and I end up
with field recordings where the two channels are not balanced. I have
corrected this in post-editing by normalising the tracks separately
using Audition, but I guess this is not as nice as doing it properly
in the first place.

To overcome this I have taken to doing as follows: at the start of my
day in the field, connecting and switching everything on ready to
record, then finding a "general" noise source (a passing aircraft or
traffic rumble, even my car engine !) and turn up the record level
until the meters register about -12dB, then set the trims at a
balanced dB level for each channel eye-balled to approx 80% of full
turn, then turn the record level down again and just use that for my
days activity. This seems to work for me. I know that if I try
fiddling with the trim pots later during a recording, all I do is end
up making a big mess of that particular piece.

It is all a bit of a pain, and I am sure there may be a better way,
and in fact have been thinking of asking how others deal with this.
This coming weekend I will experiment with Dan's recommended
proceedure  to see what that tells me. Someone else in this group
suggested wrapping a small elastic band round the trim controls to
make them easier to adjust, I have not tried this as once set I want
them to stay where they are.

Hope my personal learning helps, and that in future models Fostex will
tell us how they really work, and give us knobs that can be handled
and locked in place once set ! I wrote to Fostex after buying the
machine for better advice but got no answer. This criticism aside I
have been very happy with the investment I made.

Best

Chris




<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