tufunuf wrote:
The hum is not a problem with converting the cassette tapes he is now doing. My question is related to how to remove the hum that is on the recording he has already done.I am not needing to know how to keep the hum out in the future...only removing it from the existing recordings. And...it's not a matter of if he is "tufunuf" to show up here;since that would do little towards him being able to fix the problem. We simply need to know how to remove the hum from the completed recordings.
...thanks in advance 
If the hum is not a problem with converting the cassette tapes he is now doing, why cannot he use the "humless" technique that he is now using to rework those cassette tapes so that there is no hum problem? It is far better to get it right in the first place (i.e., to avoid introducing hum where no hum belongs) than it is to use a faulty setup, introduce hum into the file, and then try to get it out! The major problem with attempting to wipe out hum from a sound file is that the hum spectrum will almost certainly be vying with the wanted frequencies within the same spectral region. Therefore, filtering out hum frequencies will invariably remove some of the wanted frequency content. And guess what? If you don't put those unwanted hum frequencies into the file, then you will not be faced with removing some of the wanted frequencies when you remove some of the unwanted frequency content. :-)
This being said, there is no absolutely sure-fire method for eliminating hum once you have been infected with the HumBug. In order to attack this Bug with any reasonable degree of success, it is necessary first to determine the frequency content of the hum. This determination requires something which is called a "spectral analysis." It is discussed in the WavePad Help file, under the title "Discrete Fast Fourier Transform" or "Temporal Fast Fourier Transform." The difference between these two methods is that the former is a spectral snapshot at one particular point in time, whereas the latter is a spectral analysis covering a certain time span. You may find the tools for performing these analyses in the (where else?) Tools menu.
After you find out what your ailment is (the analog of a medical diagnosis), you can then set about designing a frequency filter in an attempt to remove the offending frequencies. This is also discussed in the Help File.
Read the discussions in the Help file (both as they relate to Fast Fourier Transform analysis and to filtering out unwanted frequencies) to find out how to proceed to solve your problem. Alternatively, go back to square one, dig up those original cassettes and rework those conversions. This will avoid having to dig into the Fast Fourier Transform procedures. In other words, you may wish to rethink your approach to this hum-elimination problem which, when it "works," will most likely only remove some of the hum, however "hum" may be defined. One has to be careful in defining this fuzzy word in any particular case.
Welcome to Fast Fourier Transforms!! :-)
Happy adventuring.
gooroo
