Tiny dropout "crackling" repair?

Audacity Help Forum Windows
1

Ok, I’ll admit that I have not done much research, and I am very new to all this. Just looking for a quick answer, if one is available.

I recorded a single track in a drunken fit, and I really like it for some reason. The problem is that, in my stupor, I completely ignored my levels. What I was left with was a track that is fraught with tiny, fraction-of-a-second dropouts. They sound like small crackling, but are like reverse clipping. I have included a picture below. I wonder if there is a more, um, automated way of repairing these than going though and using the “Repair” effect manually on every one of the hundreds of these. Thanks for any help!
dropouts.jpg

2

That could be tough… You’ll probably have to experiment with a few things. You can try the Click Removel filter (“effect”). There are lots of applications for removing clicks & pops from vinyl recordings, and one of those might work. [u]This page[/u] has a list of vinyl clean-up programs. (Most are not free.)

I completely ignored my levels.

That should NOT have happened!!! You might need a different soundcard, or maybe just updated drivers. If you over-drive your ADC (analog-to-digital converter) it should simply [u]clip[/u], leaving you with flat-topped waves. Clipping is distortion and it’s bad, but what you are getting is even worse! :frowning:

Technical stuff… This CAN happen with poorly written software. For example, with binary signed integers, the MSB (most significant bit) is used as the sign bit. If you count-up high enough to affect the MSB, the sign will “flip” to negative. And, since most computer software uses two’s compliment format, which means that instead of it starting over at minus one, it’s will start counting down. With 16-bits, you can count from −32,768 to +32,767.

If you count in binary, here’s what you get -

0000000000000000 Binary = 0 Decimal
0000000000000001 Binary = 1 Decimal
0000000000000010 Binary = 2 Decimal
0000000000000011 Binary = 3 Decimal…

0111111111111111 Binary = **+**32,767 Decimal
1000000000000000 Binary = −32,768 Decimal
1000000000000001 Binary = −32,767 Decimal
1000000000000010 Binary = −32,766 Decimal
1000000000000001 Binary = −32,765 Decimal

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I recorded it using Sonar X2 with ASIO4ALL through a cheap Radio Shack mic plugged into a TASCAM 4-track, which was lined out to my laptop’s onboard audio. I know, ghetto as all-get-out.

I’ll look into a vinyl fix software. Thanks for the suggestion. Anything else I can try? I played with the “Find Silence” and “remove click” tools, but came up with really nothing. “repair” seems to work, but, like I said, there are literally hundreds of these things.

Thanks for the reply!

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One of my first attempts at modifying a Nyquist plug-in was a modification to “ClipFix”.
The modified version of ClipFix may be useful here, though I don’t expect it to work with all of those inversions.
See here for the modified ClipFix https://forum.audacityteam.org/t/clipfix-see-waveform-pic-plugins-available/4171/43

Note :

  1. You will need to split the stereo track before using this effect (Click on the name of the track and select “Split Stereo Track” from the drop down menu.
  2. This effect is slow and inefficient. Try it on a short section first.