Audio Workflow for noisy recording

[Michael Gissing]

[Bob Cole] “is there a “frequency analysis” filter which will give me information for EQing?”

Your ears are the best guide. It sounds like you are out of your skill zone here and the best advice I can offer is to send this to an audio pro who not only has better noise reduction but also understands the intricate balance between EQ, editing, mixing, dynamic range control and noise reduction.

STP is a useful tool but if you are already struggling with noise reduction, I don’t think it is going to save you. Multiple applications of noise reduction may help but without hearing the problem, it is hard to say. It is always a better idea to pre EQ.

[Bob Cole]

[Michael Gissing] “It sounds like you are out of your skill zone here and the best advice I can offer is to send this to an audio pro”

Couldn’t agree more, and I’ve broached that topic with the client.

But for my own learning, as well as future projects which may not have the time or budget for outside assistance, I’d appreciate any more guidance. I take your point about EQ before noise reduction, which seems like a blunt instrument in this case.

Specifically: I thought there was a spectrum-analysis tool which essentially could help in the EQ process.

and: I’d be curious what you thought about workflow: whether I should treat the original files, vs. the edited clips, given the fact that there are only five original files vs. dozens of edited clips.

Thanks again for your help.

Bob C

[Michael Gissing]

A spectrum analyser will show you what is there but only with your ears can you tell what is noise and what is good signal, unless you have a very obvious bump like a hum or whistle.

A lot of the skill in reducing background noise elements is editing out noise and applying fill if it is a noise like background kids voices. Also selecting and cross mixing between the two mics will reduce background by just focusing on the correct channel. For these reasons, I would not blanket noise reduce the whole clip, but treat each on its merits.

Also just in case you do need to export an OMF for external audio work, your original clips should remain unprocessed.

[Ty Ford]

1. Noise reduction. When I apply the Noise Filter in Soundtrack Pro, it achieves almost nothing, unless I choose such an extreme setting that an odd, science-fiction type distortion appears. What would you think of applying EQ first? If so, is there a method for analyzing the desired and undesired portions of the clip, to help determine which frequencies to boost, and which to mute? iow, is there a “frequency analysis” filter which will give me information for EQing?

> There is a graphic spectrum analyzer option in STP that can show you where (what continuous frequencies) may be causing problems and a graphical editor to remove them.

Would applying the Noise Filter several times help to prevent that odd distortion problem?

> maybe, maybe not

2. Workflow. Although they’ve been broken up into many clips in the timeline, there are only five original clips for the entire show. So this should be easy. But the background noise does change from time to time, and because sometimes the left channel is better, sometimes the right, the timeline in Final Cut Pro looks quite checker-boarded. And because the edited show is 8 minutes out of a one-hour session, there are minor changes in the noise in the background.

If I send the clips from FCP to STP, each edited clip has to be handled in STP separately. Could/should I just do the EQ/Noise Reduction for the entire original clips? If so, what’s the best way to do that? I’d be a little scared about destroying the originals, of course, so I guess I would make offline copies of them first.

>based on what you say, varying noises, I’d be apt to try each one separately as ling as they weren’t right next to each other on the timeline.

(Thanks for reading this lengthy post. I tried posting in the Soundtrack Pro forum first, but received no replies.)

>We’re always happy to help when we can. I have a VERY similar problem over here right now, Bob.

Regards,

Ty

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