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Why don't we have noise reduction built into our field mixers by now?


Chris R

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Since noise reduction plugins are becoming more and more common in post production software programs and also easier and easier to use these days why don't we have this available yet in our field mixers/recorders?

 

Is anyone working on something like that?

 

Of course you wouldn't use it 100% of the time but in the right situations I think it would be invaluable.  Even at the very very least if we are in a bad envronment we could test it, and let the client know if they will be ok or not. Situations where we currently have to guess.

 

Doing it in post is always going to be better (at this point), but as I'm sure most of you deal with, not every single thing goes through separate audio post. Being that cameras are turing into mini computers, shouldn't sound products start pushing those same boundries?

 

Would be interested to hear what you guys think either way.

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1) We would be doing critical listening in an environment not conducive to critical listening and to do a proper job would require good rehearsals which we often don't get any more.

2) Therefore, a compromised end product in respect to a correct work flow.

3) Even if the results were marginally acceptable it would contribute to putting more post folks out of work.

Sounds like a triple play to me.

BY FAR the best noise reduction that can be accomplished on set is to eliminate as many noises as possible where they originate. The time spent tweaking a software NR system is time better spent doing our main job and dealing with the noises in the first place.

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If you wanted to try live NR on your mix track, esp in that there is a good possibility that that mix will only be used for monitoring, dailies, editorial but not for the eventual mix, why not?  I used to use an expander on location as a way of suppressing HVAC and film camera noise, but I was rolling a 2 channel Nagra so I could give them a clean track too.  As long as your isos are still unprocessed then you could give it a try (unless your client is for sure going to use your mix).  An issue I have with this is that of distraction from the other tasks of production sound, and the fact that you may be masking a problem you could more elegantly fix by other means (ie the old-fashioned way).  I know that live TV mixers sometimes use realtime NR (Cedar etc).  The monitoring evironment isn't ideal and you have no idea how the scene will be cut or how it will sit in the eventual mix--these are why you would have to provide an unprocessed version of whatever you do.  I will say that with how massively improved audio post sound repair has become, I'm never tempted to do this kind of thing on location anymore (in the old days many productions had very limited or non-existant audio post, so we had to do what could be done in the field).

 

p

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1) We would be doing critical listening in an environment not conducive to critical listening and to do a proper job would require good rehearsals which we often don't get any more.

2) Therefore, a compromised end product in respect to a correct work flow.

3) Even if the results were marginally acceptable it would contribute to putting more post folks out of work.

Sounds like a triple play to me.

BY FAR the best noise reduction that can be accomplished on set is to eliminate as many noises as possible where they originate. The time spent tweaking a software NR system is time better spent doing our main job and dealing with the noises in the first place.

 

While I agree with what you're saying it's pretty easy to see the opposite side to the arguments.

1. A huge % of sound recordings out there are talking head interviews. HVAC systems (that can't be shut down) and a 100 other

consistant style BG sounds. No rehearsal needed.

 

2. I just don't see that being 100% correct. 10 years ago sure.. but the NR plugs are getting ridiculously good

and easy to use. The algorithms on all the plug ins out there (LA2A's to SSL channel strips) while in the past were good, but not

quite there are getting extremely good and only getting better.

 

3. Speaking for at least myself I would never use a NR plug in the field if I knew it was going to proper post.

Sad reality is, a LOT of things out there never reach a separate audio post guy/room. Whether its a corporate shoot,

or a news gig etc. As far as putting post out of work, while I respect you for having posts back times are changing, and in defense

to post there is a bit more too it than NR. If all post did was slap a NR plug in on the mix his job isn't exactly stable to begin with.

 

Once again, I totally see what you're saying I just feel there is more situations than you might be thinking.

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It will come, and you can do it now if you can either run a computer or rack unit as a processor. There's a lot of good reasons not to do it, but there are a few good reasons to do so.

The interesting thing is I bet it comes to consumer products (cameras, recorders) before we get it in pro gear.

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I sort of feel like I have enough on my plate while on set. Especially since I am seeing less and less occasions to have a boom op or A2. If the client wants to be cheap and skip post, they need to be happy with what I give them. If they give me noisy conditions to record, thats what they get recorded. In the end it is their project, and although I want to do my best and be proud of my work, I dont see why my duties and expenses should increase just so they can cut more corners. In my mind I shouldnt be enabling that sort of behavior.

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I can say, that in my days having worked post, if I got tracks that had any processing on them besides mild eq (and even then I didn't want that) I would not be happy. I always wanted what was coming from set to be what was coming from set. Processing is a destructive process if you do it while recording. There is no going back. What if in your headphones it sounds fine, but on the dub stage or edit room it is littered with artifacts? Also, this is not something I'd want to be responsible for when working on production. There is enough going on. 

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Dual output channels on the Super CMIT, noise reduction processed, or not, post can choose.

By being at the point of capture with live sound, and processing differences of sound arrival timing with two capsules it's achieving noise reduction in 3D that can't be replicated by noise reduction from a mono track, effectively in 2D.

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As an example, some surf competition stuff I do, I work on content teams where we go and shoot interviews on the beach, and after we wrap the interview, a PA runs the card to a trailer where it goes to broadcast in 20 minutes or less. On one hand it would be nice for the cutters to have the time to do it, but reality is that they don't and they just aren't those type of guys even if they did have the time. On everything else, agree that ISO tracks should remain unprocessed, but why not mix a process track too? If an AC unit can be "fixed in post" might be handy to demonstrate that in the field, showing how effective NR is on broadband like background sounds, but also demonstrate how it's not going to work on a motor with mechanical clatter for example.

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Some post effects are light computationally (like eq and some compression for example) ... effects as meta data.? Nothing destructive and completely ignorable?

 

Just a thought from a picture person.. I say this because I def feel that there should be a meta data gain option built into broadcast wav files. At the moment finding 12db+ of gain is not completely simple in some picture editors.

 

Neverclip from Zaxcom pretty much needs post user understanding which is a little fanciful... (Love the idea myself)

 

I belive Gain, compression and eq are all computationally lighter than a high precision 3d LUT on a big picture file... So maybe a Audio decision list with look up table is the way forward...?

 

Just a thought (apart from the gain part which should already be in place)

 

Michael

Edited by Michael Lindsay
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Some post effects are light computationally (like eq and some compression for example) ... effects as meta data.? Nothing destructive and completely ignorable?

Just a thought from a picture person.. I say this because I def feel that there should be a meta data gain option built into broadcast wav files. At the moment finding 12db+ of gain is not completely simple in some picture editors.

Neverclip from Zaxcom pretty much needs user understanding which is a little fanciful... (Love the idea myself)

I belive Gain, compression and eq are all computationally lighter than a high precision 3d LUT on a big picture file... So maybe a Audio decision list with look up table is the way forward...?

Just a thought (apart from the gain part which should already be in place)

Michael

A very interesting idea Michael, it takes a while for camera ideas to filter through to audio, like user assignable hardware buttons (there's now one on the Zaxcom FP8 for example), but slowly they might. There's arguably been a bigger revolution in picture acquisition than in audio. So audio RAW with a LUT is not going to happen anytime soon but could indeed happen some time in the future?

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Some post effects are light computationally (like eq and some compression for example) ... effects as meta data.? Nothing destructive and completely ignorable?

Just a thought from a picture person.. I say this because I def feel that there should be a meta data gain option built into broadcast wav files. At the moment finding 12db+ of gain is not completely simple in some picture editors.

Neverclip from Zaxcom pretty much needs user understanding which is a little fanciful... (Love the idea myself)

I belive Gain, compression and eq are all computationally lighter than a high precision 3d LUT on a big picture file... So maybe a Audio decision list with look up table is the way forward...?

Just a thought (apart from the gain part which should already be in place)

Michael

 

Are you shooting with already 3D LUT in your file? No.

 

You are in the wrong direction.

 

The revolution will be in transistors: No noise

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 If an AC unit can be "fixed in post" might be handy to demonstrate that in the field, 

 

Many AC units can be fixed in post. Some can't. The ones that can, require at least a few minutes tuning the NR and making compromises... and in most cases, have had some sharp dipping or filtering applied first. And all of this on speakers that match the viewing environment, in a room with acoustic treatment. Do you really want to take the time to try this (and commit to those decisions) during production?

 

In the case of run-and-gun news that'll never get post, how about some simple-to-use NR that can be applied during ingest and trimming? Even a simplified UI for the pix editor would have advantages over NR during production, in that there could be multiple presets... or a chance to choose a best sample for setting band thresholds... or UNDO! 

 

News: it's already been applied to low-cost cameras. Sony had a godawful gate built into the PD-150, close to 15 years ago. It was to cut noise from their own lousy mic preamp circuits, but it also functioned as environmental NR. 

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I think the idea is interesting, but, as many have commented now, it should not be done in the field, or if it is done, there should still be untouched iso tracks or an alternative mix track.

Now, how about taking it a step further with a recorder that can load VST (or AAX, etc.) plugins? That would open up so many possibilities! Not at all only good oned...

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Collecting good sound is a busy enough job.

 

Perhaps noise reduction would help and you would have time to adjust and monitor on a stage

but in the field it's hard enough to do your job, follow what's going on,keep a log, catch up with the

next slate number etc.

 

Then when a scene is cut together is this application of noise reduction going to give a coherent result???

 

mike

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The Nomad channels have a notch filter which might have its uses in very specific conditions, but I'm not sure I'll ever be using even that. Apart from your usual hi-pass filter, applying something destructive to the signal on the field is a scary thought. 

 

And I'm strongly of the opinion that if a production company isn't budgeting post, then... they get what they pay for.

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  • 11 months later...

I personally won't be buy another mixer past my 664 until I see built in DSP (EQ, Comp and NR atleast availible on the master track).  I would never touch ISOs but I would bet that a shocking percentage of most of our work never sees any post.  And no I don't want to pay $3500 for the (admittedly great sounding) Cedar NR box.  The 688 and 788 already have auto mixing built in, it won't be long before all of this is available.  In the mean time I'll be buying wide band lectro SRCs!

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