Linked is a "screen print" from "Audition".
This is a quiet recording where I am reaching about 150 yards for a
Great Grey Owl, so nothing over 500 cycles means a thing and is just
wind and pre-amp noise.
The MD ragged top on this recording could not be seen at 96db
resolution but is seen here at 126 db resolution. That means that
only things at -126db or less are seen as black.
This pretty much shows the limit of a Sony MD with stock preamp.
small download under 80kb
http://home.comcast.net/~richpeet/md.jpg
Rich
--- In Walter Knapp <>
wrote:
> From: Dan Dugan <>
> >
> > Rich Peet wrote,
> >
> >
> >> > 1. When there is no audio that is important above 15,000
cycles I
> >>
> >>> drop the gain in this region by 50% to 75% (6db to 10db) on a
slope.
> >>> It does not effect the overall recording and hides the ragged
> >>> compression of this area that can be seen on a spectral display
which
> >>> is the signature to many that the recording was a MD. It
really does
> >>> not change the heard audio any, but for those that pay
attention it
> >>> fools a few of them into thinking they may be looking at a 24
bit
> >>> recording with >100db s/n. I use it with restraint but hey if
it
> >>> makes someone think that I am better and have higher tech
equipment
> >>> then I do then it was worth the effort. This part of the edit
is
> >>> vanity.
> >
> >
> > And Walt commented:
> >
> >
> >>Unless they use sonograms, few would find the MD effect you speak
of.
> >>Nor is it consistently there. If it is in your equipment, then
there may
> >>be some other fault with the equipment. It is certainly not
consistently
> >>there in all the sonograms I've done on MD recordings.
> >
> >
> > I monitor my work with Spectrafoo instruments, and the effect
that
> > Rich mentions is quite apparent in spectrum analyzer displays of
> > perceptual coded stuff. It doesn't show on sonagrams. It's a
> > sure-fire indicator that you're listening to a perceptually-coded
> > recording, even though you usually can't hear anything strange.
I'm
> > going to play with the rolloffs as Rich suggests, but there isn't
any
> > audible need for it--as he says, he does it just to clean up the
> > appearance on an analyzer.
>
> One could hardly call such equipment common. Pretty rare person who
will
> have access to such.
>
> If you could hear the perceptual coded stuff, that is a failure. A
good
> coder will do the work and not be heard. I don't think they ever
claimed
> to do nothing, only to not be heard.
>
> I suppose it depends on your sonogram software. I do see the effect
of
> coding in the high frequency end of some MD recordings. Mostly if
there
> is something of fairly high intensity in that area. You do have to
have
> sonograms that are fairly well resolved, and have to understand
what the
> sonogram software itself puts in there.
>
> I would be more interested in what specifically you are seeing in
your
> spectrum analyzer. I've got some spectrum analysis software, but it
does
> not appear to give me as good a look as a good sonogram.
>
> I note in my reading of Ken Pohlmann's book that he's gone to
triple
> blind listening tests, preferably with trained listeners. He's
pretty
> down on hardware type tests, saying they miss the point. He also
notes
> it's getting harder and harder, and that the unencoded sample does
not
> necessarily come out on top in that work. They are doing the tests
to
> improve encoders and evaluate one against another. They realize we
will
> be working with such things.
>
> He also has some ideas in how perceptual encoding can make systems
> better than without the encoding.
>
> > Because I work in theater, I often have to do noise removal
> > processing, and I keep buying expensive software that does that.
Even
> > the best is problematic, and I rarely do more than plain vanilla
> > equalization/filtering to my nature recordings. I would only use
> > dynamic noise filters on nature sounds if I was composing, mixing
> > cleaned-up specific sounds over a natural bed.
> >
> > -Dan Dugan
>
> I mostly don't filter either, the scientists I deal with could care
less
> as long as they can make out the calls. I did use considerable
filtering
> in the ID clips for the CD. Particularly in some cases where our
choice
> of material was very limited. There you are not really trying to
> preserve the other sounds. You are trying to get the call isolated
so
> people can learn it.
>
> If I use a dynamic noise filter, it's the last thing in line. After
all
> other cleanup is done. Even there it can only be used lightly. Very
> annoying filter to use.
>
> I cannot afford to continue to buy different software, though
SparkXL is
> a pretty expensive package in my thinking. Got lucky and got it off
> ebay. So only have to keep it upgraded. Having the support to
experiment
> with expensive software would be nice.
>
> Walt
>
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