my name is Bernard and I´m restoring old sound recordings (mostly ‘spoken letters’ sent over the iron curtain between Poland and Germany on compact cassettes in the 1970’s and 80’s). I have some experience in doing this, including mechanical and chemical work on the rotten tapes and tricks like playing deteriorated tapes with their backsides in contact to the playback heads to avoid the iron layer being planed off, or coating brittle tape in laquer, “baking” tape in the oven a.s.o.
I prefer doing software restorations by hand rather than using automated tools. My favourite method is viewing at the spectrograms and deleting resonances or imperfections by attenuating or amplifying selected portions of the spectrogram. Once you’ve got a trained eye, you can identify the spectral patterns of recording room resonances, jump to the harmonics of the room´s fundamental frequencies and attenuate them.
In my old version of Audacity on my 2007 iMac, I could apply the ‘attenuate/amplify’ filter and modify the selected spectrogram regions by a desired number of dB.
I paused the job for a year or so, but now, with my rather new Macbook and Audacity 2.1.1., the attenuation filter always applies to the whole spectrum. Even worse, the “spectral delete” - effect seems to have disappeared!
I am angry as f… about myself being too stupid to find the missing filters and settings. Could you please tell me if I´m already suffering from dementia, or if those useful features have been secretly removed from Audacity?
Best regards from Germany