Question: Fixing bad audio/Cleaning up single mic long dialog takes (film sound)?

Question

Hi People,

This is my first post however I've been following up on the forum for a long time now. I'm about to take an editing/restoration work and it seems like it will be quite a bit of a problem.

It's for a short film that will be sent to the Rotterdam film festival. According to the film editor: There are 2 long scenes that needs to be fixed. Long recordings of single mic (possibly shotgun).

I've checked the video exports and:

1) There are quite a lot of mic handling sounds in these recordings. 2 actors speak at the same time, speech levels are hugely different: one of them almost whispers and the other seems to be in normal voice level. On top of that add the background humming noise of lights (fluorescent)..

2) In another long shot I have 3 actors, it's quite dynamic in voice levels which I like since they are all intelligible. The main problem however is the reverb. It's recorded in a empty huge basement sorta place. And although I think it fits to the scene, the director seem to be in favor of having a very dried out sound..

So, I've been asked to remove mic handling noise, balance speech levels (between actors), remove background noise, remove reverb...!!

NOW, from what I've heard it seemed almost impossible to me (since it's single mic take), and if I'm wrong I dunno where to begin.

I was thinking of asking if they have recorded room tones and getting my hands on those first. Then applying some careful gating, and some Izotope RX magic maybe.. but I'm pretty unsure how to go about this.

Would you have any suggestions? Or should I just call the deal off? =)

Answer 1

Hi audiLE,

I have had the same problems in the past where I have been sound editor/designer and not the on set recorder.

What I suggest is you first ask for any room tones they may have recorded. If they are clean and well recorded then you may be able to mask some of the background noise. If they are not usable then its going to be even more difficult for you.

Getting rid of handling noise isn't too much of a problem as long as it doesn't occur during dialogue that is going to be used. You can just cut out the handling noise if its on its own and the room tone should cover the gap (if you have it)

Two actors talking over each other will need to be re-recorded (unless that's the result the director wants.)

Reverb is notoriously difficult to get rid of. Most of the professionals I have heard talk about this have had to either re-record the entire scene which the reverb has ruined or use Foley and sound design techniques. I have had some success in getting rid, or reducing the reverb a little in experiments I have done but I still don't think its good enough yet to be applied to a festival bound film.

The florescent light bulb tend to hum at a specific frequency and stay there whilst they are on. Just use a parametric EQ and sweep across the board (unless your hearings good and you know what frequency it is :D ) to pin point it and then reduce or even cut that frequency out.

For the different levels of the actors voices first thing I would try is normalizing the audio file but this often brings out loud unwanted background hiss. You can get rid of the hiss with extensive E.Q-ing depending on how bad it is. If this is does not work then becasue they are only on one track, ADR will more than likely be needed.

I hope some of this information helped, If you want to talk more about it, or my reverb removing technique (but remember it doesn't always work, that's why I haven't posted it here yet) Add me on Facebook search Blank Canvas Sound Design and I have a black and white picture. I will gladly help out as much as I can.

Also, you might want to read this pos: How To: Minimizing noise and reverb with DIY multi-band expansion.

It may help.

Good Luck,

Scott

Answer 2

Hey! I'm just going through exactly the same problem!

I came up with some simple things who had reduced like 70% of the noise 40-50% of reverb.

The scenario was just the same: 3 people having dialogue, one shotgun terribly placed, an empty bar with no furniture and large windows. Most of the noise came from refrigereting machines.

My advice is as if don't have any access to another takes.

1) Noise: use Wave's X-noise! It is incredibly efficient, quick and simple to use. I had to use two in some moments and I tell you the voice didn't suffer any losses. It's easy to know that since (if you don't know the plug in) you can hear the noise it takes out, adjust threshold and reduction level. About the handling noises, it's harder but include that in the noise you want to cut off in X-noise.

2) Reverb: use Sonnox's expander. I know it is weird but just try it with a medium threshold and it will cut most of the tail. Also, try to find the frequency's room response. If you cut about it 3 to 6 dB you will get a much cleaner voice. I cut it in at 500 Hz which may be problematic in dialogue but the voice got much better.

You may be able to separate even the same voice in pieces and make separate treatment.

I may provide you with some samples if you like. E-mail me if you want at [email protected]

Cheers everyone.

Melissa

http://sounditmelissa.tumblr.com/

Answer 3

This is going to be an issue of managing your client's expectations. Make sure the director is aware of the difficult nature of the work, and WHY it is difficult. Obviously, you have to be careful doing this. Pointing out problems has to be presented in a constructive way. Talk about the possible solutions available and what effect they will have on the audio (both positive and negative). You don't want him or her to be surprised with the result in a negative way.

Some tricks you can try as far as noise reduction (I'll touch on some different ideas than Blank Canvas, who gave you some great information):

It sounds like you have Izotope RX:

-You can use this to deal with mic bumps pretty easily. The bulk of their frequency content tends to be in the very low-end of the spectrum. So even if there are some in concurrence with the dialog, you should be able to pull them down. Cpmpletely remove any fundamental frequencies of the bump that occur below the voice fundamentals, then you can carefully use spectral repair for any lingering remnants that occur higher up in the spectrum (use extreme care when doing this second part though).

-Your background humming/buzzing noises are probably going to be relatively steady in terms of frequency content, so Izotop should be able to handle these relatively easily.

Reverb Problems:

-My go-to trick is multiband expansion. What you're trying to do is create more separation between the direct and reflected sounds, but you still want to have a natural tail out. Gating tends to be too extreme, and will chop off the tail. An expander helps create that separation between the source and the room in those really active frequency bands, and using a multiband version (like Waves C4) lets you really hone in on the trouble/really reverberant spots.

Answer 4

you're going the right away about it already it seems, if it's any help this is what I've done in this situation.

1) ask for alt. takes, you can replace some dialogue and cut it up to match lipsync. Stretching the vowels in words can help you fit them.

20 ask for room tones and ambiences, draw out bumps etc and cover using tone.

3) explain to the director what the effects will be of using noise reduction or not having any room tone/alternative takes and why you may need to even go for ADR if he is not happy.

4) set your levels, set your fades do it manually, i wouldn't use normalize as it consolidates your region and you can't stretch it out if you've cut off the end of an S for example.

5) use WNS noise reduction or izotope (as you have it), set your levels again

I've never dealt with very reverberant rooms and a director wanting you to remove it, explain it could need ADR and that means spending money and he/she will probably soon think that the reverberant room adds character to the scene.

Whatever you do, don't call the deal off, this is a great learning experience!

Answer 5

Thank you SO MUCH guys!

All of your inputs have been very helpful already to get my mind around it! (This is why I love this community!)

I'll try to work step by step as soon as I get my hands on the actual material and possibly make an update on this thread in re to my success level =)

Cheers!