Topic: Best "hiss" reduction? - Help me save this recording!

[Rairun]

I'd try a pass of noise removal on the channel with hiss, and mix it with a duplicate of the good channel instead of boosting the volume all the way up. You will lose some stereo separation, but not all of it, and it might be enough to keep the noise down.

[moondust.and.solitude]

If you have a stereo file that's only going to have an increased noise floor on one side your best bet is to split the file into two mono files and work on them separately - which is why I don't understand why you just wouldn't duplicate your known good channel and use some tricks to get stereo separation perception out of it. But, hey, it's your recording.

I have to agree with this. I have lots of mono recordings from "way back" when buying a stereo recorder wasn't always an option. Lol. In transferring these oldies I have used this VST within Adobe Audition 3 and the results is impressive. It really gives it a stereo feel ...

"SHEPPi" Spatial Enhancer.

http://dallashodgson.info/articles/OpenAmbienceProject/

[fanofjam]

Not to pile on, but I've never had an issue with creating stereo in post either.  I don't really consider that fake stereo any more or less than having my two coincident mics flying in a venue is fake stereo...it's just two mics pointed in different directions.  For what we do, it's not like the right and left mics set up in coincident recording patterns are recording different sound sources.  The positioning of the mics causes the perception of right and left either due to differences in sound pressure or differences in sound timing...both of which can be created in post.  So whether stereo is created in post by futzing with two mono files to create differences in sound pressure and/or differences in timing, or by two mics in the venue, it can end up being really similar sounding. 

(Not to mention that some sound guys don't send stereo mixes to the PAs.)

[Gutbucket]

If the recording is important enough to you to put the post-production work into it, and if the noise isn't audible during most of the musical sections that are more energetic..

1) Duplicate the recording to additional channels in the DAW.  Keep the two copies identical for the time being and automate a cross fade between them just prior to each time the noise becomes objectionable, and back again to the original just after it becomes unnoticeable.  If you were to listen to the output at this point it would sound identical to the raw recording (the cross fades are being made back and forth between identical copies).

^You are now setup to try a few different things to fix the noise problem by applying whatever you do to only the copy that is cross-faded to during the noisy sections. Whatever treatment you apply will only affect the noisy parts of the recording, the parts where the noise is not perceptible will not be effected at all.

2) Try applying noise reduction in Rx.  Tweaking settings for minimal artifacts.  lf it works decently enough you are done.

If not, try instead..
3) Whatever other noise mitigation technique you want  (such as coping over only effected frequency region from the good channel).  If it works you are done.

(with either of the options above, if you can reduce the noise somewhat yet not sufficiently to keep it from being objectionable mostly because it is only on one side, you can try adding a little bit of noise to the clean side.  The noise will then at least sound balanced rather than lopsided.  Like a cassette.  Retro analog.  If acceptable, you are done.)

If not try instead..
4) Monoize to the quieter channel during the noisy sections.  The recording will cross-fade from noise-free mono during the quiet parts to stereo during the louder parts.  If acceptable you are done.

4a) Try applying pseudo-stereo techniques if you like.  The recording will cross-fade from pseudo-stereo during the quiet parts to stereo during the louder parts.  Tweak the pseudo-stereo with an ear toward minimizing the difference in spatial feel during the transition to and from real stereo, rather than seeking the most attractive pseudo-stereo effect on its own.