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RE: draft procedure for amateur recording in parks, v. 2

Subject: RE: draft procedure for amateur recording in parks, v. 2
From: "Gene Dorcas" <>
Date: Wed, 31 Aug 2005 10:05:26 -0500
Thank you so much for your efforts. We've needed this. While I'm still a
newbie I can appreciate a benchmark that I can use when purchasing and using
my recording equipment.

I am currently using a NH900 and RH10 as recorders and 2 sets of 183's.  I
wish for the financial ability to purchase MKH quality but it's nice to know
that my rig falls within the specs as you've listed here.

I have 2 sets of 183's.  One pair is used as binaural for ambience recording
and the other pair is in a DIY parabolic.  My current need is a pre or other
way to attenuate the signals from my parabolic pair. It frequently over
drives my recorder(s). I have to set the mic sensitivity to "LOW". I
recognize the MP2 as sort of a standard pre but my question is - does the
current model, Sound Design "MixPre" sufficiently replace the Mp2.
Thank,
Gene

-----Original Message-----
From: 
 On Behalf Of Dan Dugan
Sent: Saturday, August 27, 2005 1:56 PM
To: Nature Recordists
Subject: [Nature Recordists] draft procedure for amateur recording in parks,
v. 2

Dear friends, this is what we're doing in Muir Woods. Your comments 
will be appreciated.

-Dan Dugan

Recording Protocol for Soundscape Monitoring
Version 2.0 (Draft)

This is an attempt to set standards for audio recording in 
conjunction with attended soundscape monitoring, so that the work of 
different recordists will be comparable.

Format
        Stereo digital audio.

Microphones
        Type: condensor.
        Frequency response: at least 40Hz to 16KHz
        Equivalent noise: lower than 25 dBA (signal to noise 69 dB or
better).
        Effective windscreens are essential. Manufacturer-provided 
foam windscreens are inadequate for outdoor work. Good windscreens 
can be home-made.
        Shockmounts are highly desirable, especially if hand-held.

Stereo Microphone Arrays (listed in the order of preference, best first)
        A: Spaced omnidirectional mics with barrier: Jecklin disc, 
shoulder mounts, head-worn quasi-binaural, lavs tied around a tree.
        B: ORTF array (cardioids spaced 17cm, splayed at 110 degrees).
        C:  One-point stereo mic X-Y or M-S.
        Highly directional types like shotgun or parabolic dish are 
not applicable for soundscape recording.

Recorders
        Any digital audio recorder with adequately quiet mic preamps. 
MiniDisc, Compact Flash or hard drive are all good. A record level 
control with steps is a plus. Some kind of scale on the record gain 
control (at least 0-10) is necessary for repeatability.

Recording Level
        To establish a starting point, hold the microphone at arms 
length, sensitive side facing you. Speak normally to a person near 
you. Set the recording gain so that the peaks don't exceed a level of 
-5dB on the recorder's meter. This gain will work for quiet 
environments. Loud sounds will require lower gains.

Calibration
        An affordable scheme for calibrating field recording outfits 
is being sought. Here is one proposal:
        Terminology: "Recording Gain" is the setting of the recorder. 
"Recording Level" is the reading of the recorder's peak meter.
        Equipment: A digital audio workstation with speakers, a sound 
level meter, the recording outfit to be calibrated.
        Procedure:
1) Prepare a stereo track of pink noise. Make the channels 
uncorrelated if possible.
2) Filter the track with a high-pass at 200Hz and a low-pass at 2000Hz.
3) Play the track and read the sound level meter while adjusting the 
monitor level to 65dBA (slow) at a normal listening position 
(measuring position).
4) Place your mic precisely at the measuring position and adjust the 
recording gain so that the recorder's peak meter reads -5dB (this is 
dBFS, meaning "decibels full-scale").
5) Note your recorder's gain setting. Use this as a standard gain for 
recording in quiet places.
6) Make a one-minute recording of this calibration noise. Save it to 
calibrate transfers later.

Slates
        Each take should have a voice announcement (slate) at the 
head or tail including:
                Recordist's name
                Date
                Time
                Location
                Weather and wind conditions
                Microphone(s) model number
                Recorder model number
                Recorder gain setting
                         Optional description of the scene and the 
sound sources you can identify, observed wildlife behavior.

Monitoring
        Recording should always be monitored on headphones except 
when doing simultaneous attended logging. Attended logging must be 
done with naked ears.

Delivery
        Make a CD with a track for each monitoring location. Five 
fifteen-minute locations with one-minute slates will just fit on an 
80-minute CDR. Write your name, the date and the time-slot on the 
disc with a list of tracks.
        Tape a Tyvek CD sleeve inside a standard file folder. Write 
the slate and track information on the outside of the folder. Put a 
code number on the folder tab: YYMMDD-T (year-month-day, time slot; 
example 050720-night)




"Microphones are not ears,
Loudspeakers are not birds,
A listening room is not nature."
Klas Strandberg 
Yahoo! Groups Links



 






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