How to face with this challange?!

I’m a complete beginner in sound editing. For a short time I became familiar with Audacity. Ok, my task is the following: “Remove all simulated noise in the audio file zadatak(task).wav. The goal is to use various software tools such as noise reduction, click and crackle removal tool,
wave line edit tool, equalization, etc., to eliminate the interference characteristic of vinyl reproduction
The final volume should be the quality that is closer to that found in the audio file resenje(solution).wav.”

The image above shows the appearance of the sound waves. The top one is task, and the bottom one is solution.

What I have done so far is a noise reduction using Noise Removal effect. What should be done next and what effects to use to handle the challange?!

The best vinyl processing isn’t inside Audacity. It’s an outside software package called Click Repair and it’s money-based software.


The job can be done in Audacity.
The link Koz provided will points to the Noise Removal and Click Fix effects.
There are more “Repair Damaged Audio” effects listed here,_Generators_and_Analyzers#Repair_damaged_audio
The Draw tool is described here: but should be used with care - it is possible to due more harm than good with this tool.
The Equalization effect is described here:
After performing all the “repair” functions, you can use the Plot Spectrum analysis tool to compare the frequency response of the task file and the solution file. Plot Spectrum does not compare two spectra automatically. You’ll need to plot the spectrum of each file and make manual notes of where they differ. You can then apply that difference using the Equalization effect.

– Bill

Try viewing the sound in “spectrum” display rather than waveform, it will help you identify clicks : they produce a large spike which usually covers all of the audio spectrum, (clicks are not always obviously large on the waveform display) …
waveform and spectrum view of two copies of same sound.png
Playing the track slowly, say half speed, will help you spot defects which need to be repaired.

I’m with Koz on this one - Brian Davies’ ClickRepair is one of the “best in class” it’s results are just a little shy of magical - well worth the forty bucks if you have a lot of vinyl to process. See this sticky thread:

I used to do what was suggested by Trebor and manually removing my clicks, orginally with the Draw tool and later with the Repair effect when that was introduced - but that was tedious and time consuming - and I always missed some!

My workflow now is

  1. capture (audacity set at 44.1kHz 32-bit float
  2. export a 32-bit WAV file of the capture
  3. pass though ClickRepair (32-bit in => 32 bit out)
  4. import the repaired file into Audacity
  5. all other processing: intertrak clean-up, track labelling etc
  6. Export a set of WAVs
  7. backup the Wavs two two external USB disks

A few points:
a) I never bother to Save an Audacity project for LP/tape cature - no need
b) I prefer to work one side on an LP at a time - I like the smaller working set
c) step 2 above also gives me a raw capture backup should I need it
d) point 7 above is the most important part of the workflow

This workflow from the manual may be of interest to you:


Homework alert ! :slight_smile:

The task of signal processing

Using a software package for sound editing (Audacity, SoundForge, WaveLab) to remove all simulated noise in the audio file zadatak.wav.
The goal is to use various software tools such as noise reduction, click and crackle removal tool, wave line edit tool, equalization, etc., to eliminate the interference characteristic of vinyl reproduction plate.

The final volume should be the quality that is closer to that found in the audio file resenje.wav. Estimated time to work: 30 minutes

So if you’re not restricted to (free) Audacity, using a free trial version of Brian Davies or Goldwave seems a better idea.

Thank you all for the responses. Your advices helped me a little. And it’s not a homework! :smiley: It is some kind of high school competition in my country:

The software to be used in competition

The task of graphics: Adobe Photoshop CS4
The task of the animation: Adobe Flash CS4
The task of the video: Adobe Premiere CS4
The task of audio: Audacity 2
From here I am restricted to Audacity 2(I think I can forget about Brian Davies or Goldwave!)

I’m pretty good in the first three, but sound editing don’t go well. Maybe I just have no talent for music! :smiley:

If you guys are not bored here is the example of task(the task from my first post but here is the audio):

From here you can hear how much the audio in zadatak(task).wav is damaged. And the audio in resenje(solution).wav looks me unbeatable. So can you suggest me some techniques which use standalone Audacity?!

The tracks are stereo, some of the noises only occur on one channel (e.g. left only), it may be possible to remove the defect on one channel and patch the gap with a copy of the other channel at that point.

Is the time limit to repair this really 30 minutes !, it should be more like 30 hours.

None of Audacity’s native effects (i.e. the ones it is shipped with) can deal with vinyl surface noise (aka “crackle”).
There may be a de-crackle (VST) plugin which can be used with Audacity, would that be breaking the rules ?

Yes it is only 30 minutes! :slight_smile:

I split stereo tracks and did exactly that, but there is a lot of others frustrating crackles and clicks which i can’t tackle. Can you hear in resenje(solution).wav that the sound is little bit smoother and softer. Is this equalization effect?

See also:

The “solution” is something to aim for, IMO from “zadatak.wav” it is not possible to create something indistinguishable from resenje.wav , no matter how much time and money you had.

rolling-off the higher frequencies, above 5KHz, using the equalizer will reduce the crackle, but the music will sound dull as a result.

I suggest trying to find a de-crackle VST plugin which you can use in Audacity, I’ve had a quick look on the net but all the “free” stuff I can find is “cracked”, and I suspect comes with a bonus malware payload.

Wow that’s not long.
This is my 30 minute attempt and there’s a lot of mistakes due to the time limit.

I don’t think there’s anything in the standard Audacity that will really touch the crackle - it’s too heavy for the “Click Removal” effect and far too extensive for manual repair.

It’s a good exercise, but I agree with Trebor “from “zadatak.wav” it is not possible to create something indistinguishable from resenje.wav”, though with additional tools and more time it is possible to get closer than my attempt.

The “spectral {noise} gate” VST plugin below is free, usually* works in Audacity (* occasionally crashes), Windows only.

it seemed to reduce crackle, (I only tried it briefly).

Well if we’re going to allow other programs :wink:, here’s the same as previously after running it through Gnome Wave Cleaner (Linux only)
(Not as good as it should have been as it should have been cleaned much earlier in the process - certainly before I encoded it to Ogg).
So as to avoid compressing twice, this one is in WAV format (27.84MB)

To do the job properly I’d really want a couple of hours and GWC in addition to Audacity.

The specification was “Audacity”, so using a (free) VST plugin within Audacity may be acceptable,
( should be extra marks for using initiative :slight_smile: ).

As that is the entire track some unscrupulous competition entrant could pass it off as their own work. :astonished:

What about the 30 minute limit? I was under the impression that this was “in exam conditions”.
Another “unscrupulous” approach would be to mix in 10% of the bad track with 90% of the good track and submit that :smiley:
Yet another would be for a competitor to pay me my hourly rate to spend an hour on the job (kidding :wink: )
A nicer way of cheating would be for someone to pay Jeff Welty to convert GWC into a module or plug-in for Audacity (then we would all benefit) :stuck_out_tongue: