gravehill said:
SouthSIDE Glen - Just out of general interest, how do you do the restauration job manually?
I was afriad somebody might ask me that.
It's hard to give a general recipe, because the order of operation, and exactly *which* operations constantly changes, depending on the exact nature of the source.
Last month I was given the task of removing ambient noise and computer fan noise from a meditation tape. This was not long afer I worked on restoration of a recording from vinyl from somebody else. The way I wound up going about both of those was entirely different.
The vinyl restoration I passed through Clean once very lightly; after that it was mostly just going after the transient pops and clicks one at a time by zooming in tight on the timeline on each major one (in Sound Forge) and just supressing it by highlighting the individual offending peak (or dip) and either hitting it with negative volume or smoothing it with the "Smooth/Enhance" control...or somtimes both if it's a particularly nasty peak. (Note: you have to make sure when using that method that the ends of your highlights are at zero crossings in the waveforms or you could be creating almost as much noise ad you are getting rid of.) Once all the main noise is supressed, then there a bit of general cleanup and cosmetics that could include muting between songs, applying severl layers of light fades in and out to ease the transition from the muted area to the begining of the track and vice versa, etc. Then, once it's fairly clean, I run it througfh a basic re-mastering with volume, sometimes a *little* EQ and sometimes a little dynamic expansion or compression.
The getting rid of the noise from the meditition tape (I was actually sent the original master WAV file) was actually a bit tougher and more interesting of a project. It was more delicate in some ways. That one I used no NR or restroation plugs at all, they simply either didn't do the job cleanly enough or to get them to remove the noise they had to corrupt the signal too much. So I did it all manually. It took 6 seperate and complete passes to get that one down, using different tools each time. I gated out most of the noise during the silent passages (in a slow, calming meditation narritive there's a lot of silent passages
), smoothed the transition between the gate and the waveform, attacked a few glottal clicks from the speaker herself in the same method that I attacked the transients as described above, applied some dynamic expansion to the low-level hi freq stuff during the talking (kind of synthing my own "dbx-style" NR methodology), added some light reverb at the transition from talking back to the gated areas to smooth the transition to the gate and added some air back to the whole mix as a final master step. I think there may be a trick or two that I had to perform that I forget now (my engineering notes are on a different computer right now), but I think you get the general gist of it.*
I'm going to meet up with one of my bands that's playing tomorrow (Saturday) night. Their not "mine", just friends of mine who I do occasional work for and who I make it a point never to miss when they're playing because I love their stuff
. Anyway, the band leader leader (bass player) might be giving me some CD copies of old casette tapes of some of his old performances in the past that he want's me to work on to restore and re-master for him. (I'm not sure only because we have all been known to forget to bring stuff like that to live gigs before, you know how that goes
If/when he tasks me with this stuff, I'd be happy to share progress and notes on that job with anybody willing to read my pedantic ramblings
G.
*Additional note added in after the original post: I think I also did some tight parametric notching of particularly offending fundamentals coming from the computer fan, but I don't recall the specifics offhand.
