The audio files on this page accompany the 'Clean Up Your Act' article on noise reduction that appeared in SOS January 2012.
As described in the main article, I used various processes together to 'clean up' a bass part that had ben recorded as part of a demo, and which suffered from several different problems, including 50Hz mains hum, some buzzing and higher frequency noise.
The examples are as follows:
This is an excerpt from the original recording of the bass part.
This is the result of applying a bhum filter and some high-pass filtering with Tone Boosters' TB_Hum plug-in.
After the hum removal plug-in, I inserted an instance of TC Electronic's Denoise and started with the strong noise removal preset before refining the process via the plug-in's draw mode.
Just to tidy up a few remaining high-frequency noises, I applied a low-pass filter using DDMF's LP10.
This is the original part run through a compressor (TC's 24/7 plug-in). the settings have not been massively refined, but this shows how the noise becomes even worse when treating the part to typical mix processing.
This is the part with all the various noise-removal processes applied, and then run into the same compressor as for file 5. Again, the settings haven't been refined very much, but you can hear a massive difference. Although there are a few audible artifacts remaining, the part is now usable, and in the context of the mix this eventually appeared in the remaining problems were masked by other elements.