[ale] Vinyl to CD

[Daniel Howard]

Sean Kilpatrick wrote:
> On Wednesday 20 June 2007 15:36, dhhoward at comcast.net wrote:
> | When I get back to Atlanta, I'll dig up my notes on how to set thresholds 
> for automatic click/pop removal and maybe we can find a way to make 
> Audicity do the same.
> | 
> | Another reason not to get locked into proprietary solutions....
> 
> I have faced this issue in other ways, but I would suggest that
> one key question needs to be asked:
> 
> What is your own time worth?
> 
> If a $350 piece of software will save you a hundred hours of fiddling
> at the keyboard, your time only needs to be worth more than $3.50/hr.
> 
> I am a great fan of FOSS, but sometimes proprietary software does the
> job so much better that it is worth the price. Not always; but sometimes.
> 

Yeah, that's what I decided, but luckily I got into Cool Edit before it 
got so expensive.  Here's my notes on how to do the thresholding below.

I also find myself digitizing LP songs, naming them to indicate that 
they are raw, unfiltered, so that if/when I get time later 
(retirement?), I know which ones to work on.  Best, Daniel

-----

1.  Removing Hum (primary and first harmonic): use Transform, Filters, 
FFT and choose 60 Hz and 120 Hz notches.  Except for classical music 
like the 1812 Overture (with cannons!), I sometimes use a low pass 
filter at 15-20 Hz and below to clean up the file as well.

2.  For click/pop removal, I use the recommendations at this web site

http://www.a-reny.com/iexplorer/restauration.html

(great video of a cat bippin' and scratchin' on an LP on the home page)

and I start with "good quality" settings on a short piece of the file 
and listen to the results.  Depending on how much/little was removed, I 
proceed through the settings to get the one that takes enough 
clicks/pops out to make the file pleasant w/o taking away too much.

---

 From the referenced web site:

We will still use the "Click/Pop/Crackle Eliminator" panel.
The settings are rather complex. The method that I preconize is the 
following. But feel free to adapt it and make it better.
You must be aware that when you automatically remove "clicks", nothing 
is totally perfect. One could in fact eliminate all "clicks" but to the 
detriment of the sound of the music. One can also leave a few "noises" 
but with a good sounding music. Reading Cool Edit's HELP FILE can make 
things clearer.
In current practice you will have vinyl disks of four categories:

     1) Of good quality.
     2) Of average quality.
     3) Of bad quality.
     4) Of very bad quality
(We are not mentionning 'Mint Quality".)

To begin you need to ajust the 'Click/Pop/Crackle Eliminator" panel in 
ways corresponding to these four categories.

GOOD QUALITY :
       Window Sensitivity = 14
       Window Discrimination = 30
       Window Detect Big Pops = 60      Check
       Window Multiple Passes = 4        Check
       Window Pop Oversamples = 12
       Window Run Size = 10
       Check    Second Level Verification
       Check    FFT Size Auto
       Uncheck Pulse Size Verification
       Uncheck Link Channels
       Uncheck Smooth Light Crackle

Click on "Add" and save these settings under the name of "GOOD"


AVERAGE QUALITY :
       Window Sensitivity = 14
       Window Discrimination = 30
       Window Detect Big Pops = 60      Check
       Window Multiple Passes = 8        Check
       Window Pop Oversamples = 12
       Window Run Size = 10
       Check    Second Level Verification
       Check    FFT Size Auto
       Uncheck Pulse Size Verification
       Uncheck Link Channels
       Uncheck Smooth Light Crackle

Click on "Add" and save these settings under the name of "AVERAGE"


BAD QUALITY :
       Window Sensitivity = 14
       Window Discrimination = 20
       Window Detect Big Pops = 60      Check
       Window Multiple Passes = 4        Check
       Window Pop Oversamples = 12
       Window Run Size = 10
       Check    Second Level Verification
       Check    FFT Size Auto
       Uncheck Pulse Size Verification
       Uncheck Link Channels
       Uncheck Smooth Light Crackle

Click on "Add" and save these settings under the name of "BAD"


VERY BAD QUALITY :
       Window Sensitivity = 12
       Window Discrimination = 20
       Window Detect Big Pops = 60      Check
       Window Multiple Passes = 8        Check
       Window Pop Oversamples = 12
       Window Run Size = 10
       Check    Second Level Verification
       Check    FFT Size Auto
       Uncheck Pulse Size Verification
       Uncheck Link Channels
       Uncheck Smooth Light Crackle

Click on "Add" and save these settings under the name of"VERY BAD"


These four settings should cover 70 % of your needs. You will only need 
to select a setting depending of the quality of your LP record.
These settings should not interfere to much with the sound quality of 
the music. Other values are possible but at a risk of the modifing of 
the sound of trumpets, and violins, and also by smoothing percussions....

IMPLEMENTATION :
Just click on "Auto Find All Levels". Cool Edit will do its calculus on 
all the recording or the selected section. When he has finished click on 
"Ok" to start cleaning up the "clicks".


-- 
Daniel Howard
President and CEO
Georgia Open Source Education Foundation