Aaron Ximm wrote:
>
> > For those that are tempted to use the AGC aka ALC (automatic
> > recording gain control) of a Sony MD or other recording device.
>
> Out of curiosity, does anyone have comments on the automatic (true)
> limiter on Sony PCM-M1 (aka TCD100?) DAT walkmen?
>
> I've always avoided it, but read someone cautiously laudatory comments
> about the feature when the deck was introduced -- it's supposed to
> function as a transparent limiter, without doing any gain control
> otherwise. Clearly a last resort, but as I recall it did save a recording
> or two...
The problem with Sony limiters is that they are working off some sort of
time averaged level. So, they often have a fairly slow response time.
This works well where the sound is relatively steady loud, but for
recording abrupt calls in nature recording it tends to react too late
and hold too long. I found the Sony AGC to not be very useful as a
result. Setting the gain correctly manually works better.
> This is a direct result of the binary encoding of negative numbers --
> nothing you'd want to listen to, but it's interesting since it actually
> *preserves* information. The true waveform could (by the patient) be
> reconstructed (assuming the total level was reduced up front, or the file
> is converted to an editing space with headroom). I haven't been so
> disciplined; instead I usually just eyeball in a curve by hand and call
> it a day.
Back when I was still using Sony MD's and would try editing one of these
things I found just converting the flip to a flat top seemed to do as
good as anything.
> This quirk has further introduced me to some interesting discrepencies
> between my various CD players and audio cards -- my personal stereo (it
> seems) does *not* reproduce the inverted "transients", while my PC audio
> card does. I.e. I can listen to a horrible-sounding clipped recording on
> my PC, burn it to CD, and it will sound fine (with only a hint of
> squared-off distortion) on my stereo.
This is probably as much a case that the tops get rounded back off by
the conversions being done to the samples while burning to CD as
anything else. So it does not get back to the stereo.
Walt
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>From Tue Mar 8 18:22:15 2005
Message: 19
Date: Tue, 12 Mar 2002 19:55:14 -0500
From: Walter Knapp <>
Subject: Re: Tripod for the Outback?
"Brian M. Godfrey" wrote:
>
> > I also use a carbon fiber "boom pole". It's actually a cut
> > down collapsible panfish pole, originally 20', cut down to
> > 14' to make the end large enough. I use it primarily to dip
> > my hydrophone.
>
> (I know this is old, I just returned from a trip and am catching up.)
>
> Weren't you saying that one of your hydrophones was picking up RF
> interference? Was it on the end of this pole? I should think a carbon
> fiber (or metal, too) pole would make quite an antenna...
They were not related, pole or no pole that hydro would pick up radio
stations. Even lowered from a bridge by it's own cable, or tossed from
shore, the stations would commence the moment it touched the water. What
I could never figure out was it would pick up just one station cleanly,
not lots. And which station varied depending on where I was. I did not
bother a lot with figuring it out, just got a different hydrophone.
Note that the boom pole is sectional, no continuous link between the
fibers, and the fibers are bedded in a insulating resin, they are not
continuous conductors. I've had no pickup problems from the pole. Almost
all the fancy boom poles now are carbon fiber jobs. The movie boys seem
to have no problems with them. Theirs are much more expensive, however.
Before that they were metal. A boom pole by it's nature needs to be
strong and very light.
Think about a hydrophone in the ocean, it's normally lowered with a
steel cable. The trick is in how the sensitive parts are protected. The
one giving trouble did not have enough internal shielding.
Walt
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