Re: Newbie's Guide to Post Processing.....

["Avocet" madl74]

Marc,

I've had a good play with your track using Audacity V1.3 and
have pushed it a bit so you can see what can be done and the
snags.

DR000938michisssample.wav

On track box down arrow - select Waveform (dB) display

I've included the scripts below to add to the Audacity file
\Audacity\EQCurves.xml or just copy the GIFs. If you alter
the code, save a backup in case you goof up. :-)

Apply Effects - Equalisation as in
www.stowford.org/sounds/hpf800-2-4-6.gif
This is my standard bass cut which limits low frequency
artifacts when using noise reduction. The numbers are the
slopes in dB per octave.

Select sample at 00:26.700 for 1 sec

Effects - Noise Removal - Get Noise Sample.

Select all and apply Effects - Noise Removal - 9dB; 500Hz;
Attack 1.0secs
I usually use 500Hz as it gives fewer LF artifact.)

This lowers the general HF b/g noise

Select sample 01:03.400 for 1 sec. This is a distant cicada
sample.

Again, Effects - Noise Removal - Get Noise Sample

Select all and again apply Effects - Noise Removal.
Note: a second noise reduction only works with a different
frequency sample.
The general cicada noise is now lowered. Dynamic range is
too high with HF peaks near the end.

Reduced dynamic range with a "limiter" setting of the
compressor:
Effect - Compressor; 16dB; 60dB; 10:1; 0.1sec 1.0sec; make
up gain "no"; Compress based on peaks.

Now the quieter sounds are more prominent.

Listening to whole track, at 01:20.000 the high frequency
peaks tend to cause distortion.
Applied Equalization - see
www.stowford.org/sounds/step4000to10kminus6.gif
Not enough - do  it again.

This version is on
www.stowford.org/sounds/dr000938michisssamplenrnrcompstep.mp3

There is a little burbling from the double noise reduction
and a steeper bass cut would probably reduce this but remove
the pigeon as well.

I tried boosting the pigeon frequencies after finding them
using the spectogram display and applying the bandpass
filter:
www.stowford.org/sounds/bpf300to400plus6.gif
but it brought up the burble as well.

The answer to the low level burble is to mask it with a low
level parallel track of the original after rolling off
frequencies above 100Hz.

Have fun. :-)

David

David Brinicombe
North Devon, UK
Cogito cogito ergo cogito sum - Ambrose Bierce


Scripts to add into the file: \Audacit\EQCurves.xml
Save a backup first. :-)

 <curve name=3D"HPF800-2-4-6">
  <point f=3D"20.000000000000" d=3D"-26.000000000000"/>
  <point f=3D"200.000000000000" d=3D"-6.000000000000"/>
  <point f=3D"400.000000000000" d=3D"-2.000000000000"/>
  <point f=3D"800.000000000000" d=3D"0.000000000000"/>
  <point f=3D"22049.000000000000" d=3D"0.000000000000"/>
 </curve>
 <curve name=3D"step4000to10Kminus6">
  <point f=3D"21.000000000000" d=3D"0.000000000000"/>
  <point f=3D"4000.000000000000" d=3D"0.000000000000"/>
  <point f=3D"10000.000000000000" d=3D"-6.000000000000"/>
  <point f=3D"22049.000000000000" d=3D"-6.000000000000"/>
 </curve>
 <curve name=3D"BPF300to400plus6">
  <point f=3D"21.000000000000" d=3D"0.000000000000"/>
  <point f=3D"150.000000000000" d=3D"0.000000000000"/>
  <point f=3D"300.000000000000" d=3D"6.000000000000"/>
  <point f=3D"400.000000000000" d=3D"6.000000000000"/>
  <point f=3D"800.000000000000" d=3D"0.000000000000"/>
  <point f=3D"22049.000000000000" d=3D"0.000000000000"/>
 </curve>