Hello,
I'm just starting to fine tune my first ambient recordings...
I would have previously touted myself as generally competent at PC
audio editing. While sure I was familiar with Window's "Recorder",
MP3 ripping and coding, I had no idea what the real world of digital
audio editing encompasses. I had always assumed it was just all
about Level, THD, SNR, Equalization etc. What I'm discovering, is
that excellent quality recordings are truly created and ruined in the
field, but even an excellent recording can be "improved", by some
manipulation in the computer. It's not that I want to alter what was
heard, but I want to remove things like the rumble of a jet or the
barking of a dog and focus the recreated experience on the sounds I
find interesting.
Any advice on audio editing of stereo soundscape style ambient
recordings? I'm generally satisfied in regards to clipping out
defects and mending the discontinuities. I'm careful of accidentally
breaking up bird songs or frog calls, breaking at zero cross-overs
and blending levels adjacent to the discontinuity. What I'm really
overwhelmed with is the huge variety of noise and frequency response
modification processes. I'm finding I can minimize or eliminate
distant automobiles and jet rumble using a low frequency roll-off
around 200-300 Hz. Is there a satisfactory way to reduce or modify
the "white" background noise that you hear as a result of recording
such low sound levels? It's not something you hear in person, so I
don't want to hear it in the reproduction. I have tried some of the
noise reduction filters, but sometimes end up with a variety of
artifacts in the final passage. I already realize that sometimes
what I really want to get rid of is actually wind rustling through
the trees and not actually noise from the microphone, but it still
sort of disturbs me.
If anyone is willing to invent a filter for prop airplanes and
motorcycles, I would be greatly appreciative!
Anyway, enough questions for now.
Brian Bystrek
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>From Tue Mar 8 18:22:26 2005
Message: 6
Date: Fri, 14 Jun 2002 16:30:51 -0400
From: Walter Knapp <>
Subject: Re: Batteries: charging problems
Klas Strandberg wrote:
>
> The most common problem with a battery of several cells, is that one of the
> cells go totally flat and refuses to let current pass through it. When that
> happens, no cell will charge. There is no current going through the battery.
> The flat cell blocks it. It doesn't matter what you do.
>
> The cure is to open the battery, locate the cell which is flat and shock it
> with a powerful overvoltage (like 12V or something) for a very short time,
> perhaps 1 sec. Then it usually starts leading, and the battery pack may work
> as usual.
>
> But as long as the flat cell is ther, it is of no importance at all which
> charger you use.
Should you find such a situation and all the other cells are behaving
normally and in good shape, you need to do a bit more than just
overvoltage it. Connect the cell into a proper regenerating charger and
run it through several cycles. If it does not come up to approximately
the same condition as the other cells then you have only a temporary
fix. Best is to replace the individual cell, even though that will make
the new cell most likely stronger than the old ones.
Often though it's a individual cell that's failed, the rest of the cells
are not in good shape either, which is when you go for a whole new set.
It all boils down to a set of batteries used together should be in very
similar condition, especially if you tend to fully discharge the pac in
use often. You are much safer with any battery pac and will have many
less problems if you never suck that last bit out. And then use
reconditioning periodically.
A battery pac is nothing more than a convenient container for individual
batteries. The rules are really no different for them. And often that
plastic shell is costing a whole bunch in price difference with the
individual cells.
Walt
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