naturerecordists
[Top] [All Lists]

Re: Death Valley Dawn

Subject: Re: Death Valley Dawn
From: Walter Knapp <>
Date: Sun, 10 Jul 2005 10:23:22 -0400
From: "Rich Peet" <>

>
> --- In  Kevin J. Colver <>
> wrote:
>
>>> Walt,
>
> Thanks Kevin and there probably is no better one to id the western
> birds than you.
>
> On track one at 38 secs the only birds in my area that give the jet
> roar are ducks. Could this be a duck?

As I noted to Kevin, I was watching, primarily as this was the second
loud "jet". Nothing but smaller birds flowing past the mic on their way
down into the pit and water. This was a small bird. There were many
"jet" sounds at a lower level in the recording. Birds that did not pass
as close to the mic. I doubt we could sort out the species from the sound.

I did not see any ducks anywhere in the Death Valley area, nor hear
them. The water in this pit was the biggest piece of water I saw too.
Death Valley had lots of small birds, but few large ones.

> A nother thing noted but not a critical finding is the noise floor
> level is a bit more than I would expect from a mkh even at a +60
> pre-amp level so I hope that there was a little amplification applied
> in post, otherwise a review of the record chain is needed.

This site hissed all on it's own. It was clearly noticeable by ear, no
mic needed. The MKH20's in the SASS just got what was there. Other than
the mp3 encoding, which made the hiss more irregular, there was no post
processing. And I'd not used the MP2 in the recording, and even the
Portadisc gain was not all that high. Thus the fainter birds. All a
compromise forced by the site's own noise. Any more gain and the hiss
would intrude too much. Under quiet conditions, the same settings would
not get any of the MKH20's self noise, and preamp would be quiet too.

In the evening when I was setting up I tried a couple of the MKH M/S
mics as well, and prospected the area with the Telinga using the Sound
Devices MP2 as a headphone amp. I could not localize the source of the
sound well, but it was definitely strongest in the direction of the
cliff on the far side of the pit, basically the same direction as the
water in terms of available mic locations. In the evening the breeze was
15 mph, and unfortunately did not calm down by morning though it was a
little less. The breeze was increasing slowly in the morning, and by the
time I stopped recording the hiss was also noticeably increased by ear.
I'm sure this is a effect of the breeze on the rough rock surfaces
coupled with the natural echo of the place. The SASS was located where
it was best protected from the breeze and still "see" the water. The
hiss was also slightly less in that location.

In this case the part of the record chain that was making noise was
pretty obvious at the time. Not as pretty a sound as the Kelso Dunes,
but also a natural wind generated sound.

Walt




________________________________________________________________________
________________________________________________________________________

<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