Compressor usage

first thanks for this great free program!

Im trying to record audio cassettes to my computer. I have successfully done a few, but one of the tapes has issues. The volume across the audio drops off, so the volume goes up and down continuously.

The volume is audible for a bout 3 seconds then drops very low for half a second, this repeats through the whole tape. Im not sure if this is a common problem with old cassettes?

Also, there is an echo on in the audio, everything is repeated for about 10 seconds after, but its only low volume.

I can remove the echo with “Remove noise” effect, and i have been trying to use “Compressor” to reduce the high volume and increase the low volume but cant quite get it to work well. Ive looked up the help site for the use of Compressor, but it didnt help much. Is there a way to cut down the high volume and boost the low volume so they are even?

Does anyone have any tips for this kind of processing? I know my way around Audacity form using it a few times and ive been working on this 1 track for 2 days now, would really appreciate any help.

The compression tools in Audacity tend to be mathematical abstractions and not finished sound tools. Chris’s Compressor is a packaged sound processing tool that I use to even out volume changes similar to what you have. Give it a shot.

Chris’s Compressor


thanks kozikowski, im going to try it!

Print/bleed through ?

Print-through (sometimes referred to as bleed-through) is a generally undesirable effect that arises in the use of magnetic tape for storing analogue information, in particular music. The proximity of layers of tape on the spools of a cassette or reel to reel tape causes a weak imprint of magnetic information to be transferred to adjacent layers, effectively shifting a copy of the signal backwards and forwards along the tape. This can sometimes be heard as pre- or post-echo.

Trebor, thanks that sounds like it.

I borrowed the cassettes from the library, someone probably accidentely used the de-sensortisor on it (magnetic field) which according to wiki causes bleed-through!

So is there any way to get rid of it, besides simply removing as noise or lowering volume?

You could selectively use a gate or an expander on the “silent” bits between tracks where the bleed through is most obvious,

[Chris’s compressor also functions as an expander if you put a negative value in the compression ratio, say -0.3 ]

Thanks you very much, will try it when i get home!