Air Conditioning in bar scene is killing me!!

Richard J. Johnson

Richard J. Johnson

Joystick Member
We shot two long bar scenes in a very nice bar and the AC kicks on and off throuhout the takes. Since we were getting the place for free and they were about to open in a few hours I could not ask them to shut it off.
MY QUESTION: is there any way to eliminate this in post. Could I use a notch filter and try to EQ the noise out? and if I do, will that cause the dialog to be different from take to take. Or should I just add room tone and put the AC noise throughout the entire scene? I have music in Background and the AC noise is not too loud. but it is distracting.
:furious3:
 
What was it you shot if you dont mind me asking? I had a similar situation recently - shooting part of a doc in a cafe that was actually operating and the AC was noisy. Im lucky insofar as only a small amount of those shots will get into the final cut, soundtrack pro noise filter was able to bring it down a bit and its expected to be a little noisy in the shot anyway.
 
Yup, this has happened to me before.

I would not want to add or fill more AC noise as roomtone as that creates more noise, which was the first thing you wanted to eliminate. Go ahead and try notch filtering the sound to see what kind of effect you get, most often it'll cut off certain speech fundamentals. You'll either end up with the dialogue sounding a little thin or with the entire scene filled with constant AC noise. The most appropriate action to take is to re-shoot that specific scene without any air conditioning on. Since you've already recorded the dialogues, I suggest you to take a look at when the AC is turned on (e.g. in between talking heads, occurs within the first or last few words of a line). This way you can just re-record those few words without going through the entire take.

Another approach would be to take a few samples of the AC noise all by itself and invert it out of phase, the more audio samples you have the better. Once it's inverted, place them back into the track where the AC noise occurs. Hopefully this will solve most or at least half of the problem. One very important factor to look out for is comb filtering. AC noise is not like a constant sine wave where both the troughs and the crest are uniform with each other, thus canceling each other very well.
 
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I might just be stuck with it. I will go back in and see if I have the coverage to get around it in editing. I will also try inverting the noise to see if cancellation occurs. Re-shooting is not an option at this point, and I 'm really trying to stay away from ADR. I have Nuendo with 100's of plug ins on a different computer I will take the audio there and tinker with it. I don't have soundtrack or audition and I don't want to risk adding a new program in the middle of a project. thanks for the advice. It helps tremendously
 
After you have edited the scene, you might find that your noisy lines or words can be replaced with sections from quieter takes. Also, it may turn out that you only need to ADR a few words or lines.

Who knows, maybe you will get lucky and discover that your best audio performances were in quiet takes and you would have wanted to substitute them anyway into your best visual takes.

FYI, don't worry too much about absolutely perfect lip sync. Make it work.
 
Best is to room tone the place you record at without the AC sound and with.
Then locate the annoying frequency and cut it with a parametric eq.
Most AC sounds are between 50 and 60hz and their multiple frequencies above.
So start cutting at 55hz (Hi pass or shelving EQ) and 110hz
Above you will be in the voice range and remove some needed speech frequencies.

My 2 cents,

Martin
 
Overlook said:
After you have edited the scene, you might find that your noisy lines or words can be replaced with sections from quieter takes. Also, it may turn out that you only need to ADR a few words or lines.

Who knows, maybe you will get lucky and discover that your best audio performances were in quiet takes and you would have wanted to substitute them anyway into your best visual takes.

FYI, don't worry too much about absolutely perfect lip sync. Make it work.
Click to expand...

I will re-cut the scene today and see what I've got. thanks
 
Absolutsound said:
Best is to room tone the place you record at without the AC sound and with.
Then locate the annoying frequency and cut it with a parametric eq.
Most AC sounds are between 50 and 60hz and their multiple frequencies above.
So start cutting at 55hz (Hi pass or shelving EQ) and 110hz
Above you will be in the voice range and remove some needed speech frequencies.

My 2 cents,

Martin
Click to expand...

I needed that 2 cents. I have room tone with the AC off and on. I can't wait to get home and mess with it. This scene has been killing me all day.
 
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