Can't remove clunk from audio cassette transfer

[Tapehead]

I've uploaded this end segment of a piece mastered and mixed on a four track Tascam many years ago. The clunk is right near the end.

Unfortunately I don't have the master. This is from the mixdown.

I have zoomed right in with Audacity but didn't see anything pronounced in the waveform to adjust as with a pop or crackle.

Does anyone know how to deal with this clunk.

Download
http://www.sendspace.com/file/or385t

[steve]

If you zoom in vertically you will see a "wiggle" at around 7.57 seconds to 7.61.
Probably the best way to remove the clunk is to copy a short section from just before the clunk onto a new track, and then cross-fade it like this:

crossfade.png (6.86 KiB) Viewed 1621 times

The result:

no-clunk.flac

(896.94 KiB) Downloaded 71 times

Some tips on cross-fading: http://wiki.audacityteam.org/wiki/User: ... _Crossfade
Because this was just a short crossfade, I used the normal "Fade In" and "Fade Out" effects, which is quick and easy and I think the result is acceptable.

[Tapehead]

Hey wow! Thanks steve, that will do fine. I'll give it a go tomorrow evening.

[Tapehead]

I've done it once, almost right but not quite.

I'm having trouble working out vertical zoom. I achieved the desired zoom result seemingly by accident. I was able to view where the clunk was by using a combination of horizontal and vertical zoom.

But now, beginning again from scratch I'm finding that when I click in on vertical zoom the waveform disappears up off the edge of the track. How do I get it back in view? Aside from right click which brings it back into view but reduces the zoom again.

Also the view for the second track I created with the copied segment was not the same as for the primary track

[Trebor]

... I'm finding that when I click in on vertical zoom the waveform disappears up off the edge of the track. How do I get it back in view? Aside from right click which brings it back into view but reduces the zoom again.

If you want to keep the zero-line in the middle of the screen when vertically-zooming-in, mouse-click with the cursor on "0.0" on the vertical scale, clicking elsewhere on the vertical scale can make half of the waveform disappear off the screen ...

vertical zoom demo.gif (196.13 KiB) Viewed 1606 times

[Tapehead]

Got it! thanks.

My first attempt came out better than my subsequent two.

[steve]

In case it helps, a little "trick" when dealing with low level signals:

1) Select a short section that includes the part that you want to work on.
2) Press Ctrl+I (or "Edit > Clip Boundaries > Split")
3) Amplify the selection by an easy to remember amount, for example +20 dB or +30 dB - enough to make it easier to work on the selection.
4) Do whatever editing you need to do on the selection.
5) Amplify the selection by "minus" the amount that you use in step 3, for example "-20 dB" or "-30 dB".

Not really necessary. but the split lines may be removed when you are finished by clicking on them.

[Tapehead]

Great!
Another couple of tries and I got it to my satisfaction. Thanks very much for the help.

(Might I suggest - for less savvy users like me - that the vertical zooming section of the manual be updated to specify clicking on 0.0 for zooming in)

[steve]

(Might I suggest - for less savvy users like me - that the vertical zooming section of the manual be updated to specify clicking on 0.0 for zooming in)

In the current manual, it says here: http://manual.audacityteam.org/o/man/au ... html#scale

Left-click in the Vertical Scale for any Waveform or Spectrogram view to zoom in. The range displayed on the scale will be centered at the value you clicked at.

Are you looking somewhere else?

[Tapehead]

Google brings up this page for vertical zoom search
http://manual.audacityteam.org/man/Zooming

Sure, it says this:

Left-click once to zoom in at the position on the vertical scale you are interested in. This point will then be centered on the vertical scale.

That wasn't self explanatory to me at least. And my experience is that if one person doesn't get it loads of others won't either.

I know how how it is, explaining something I'm familiar with seems as clear as day to me, but it often isn't to someone unfamiliar with it. My main experience was of wondering why the track was disappearing off the scale. I must have accidentally clicked on 0.0 the first time. There was no picture of the zoom symbol on 0.0 to explain that specific point.