refrigerator's motors

G

Garinion

Active member
I'm going to shoot a movie and I have some internal shots in a hairdresser.. but next to it there is a butchery with these big outside refrigerator's motors
One way is to film only the time the motor is off .. but this is very time-consuming

I thought something else .. If I record only the motor .. could I put this sample to a program with filters to ban motor's frequency's from my captures ??

I'll use an HVX200 and a Rode Videomic as a BOMM

Thanks ...
 
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You mean to invert the solo recording of the motors and cancel it out from your video. It's very unlikely to work, because
1. The sound will change, even slighlty, and cause the cancellation to sound very "phasey".
2. The difference in distance will have the same effect as #1.

The main problem is that when the compressors are off, it will sound totally different, so make sure to get room-tone of just the compressors running without any other noises, in the same setup as your scene. (not a recording outside, record from the inside) That way, if you need to lay it under the scenes when the compressors are off, you can match it.

Those compressors are in a bad frequency range because there's a lot that will cover your dialog. I would suggest this-

- Try and get lots of heavy furniture pads either around the compressors (not to close so that they can't breathe), or, the place where the sound is leaking in the most.( doors, windows, wall?)
-Boom as close as you can to your actors, and make sure they say their line loud and clear as possible for the scene.
-Plan for some BG sound like a radio playing in the shop. Sound masking is your friend!
- In post, you can use a noise gate, which cuts out all the "in-betweens" of your dialog tracks and you can replace the BG with city traffic/ birds/ radio/ music/ rain.


Another option is to write the compressor into the scene. Maybe someone goes out there for a smoke, so we see and hear where the noise is coming from and it won't be as much of a distraction from then on.

Good luck.
 
Well your best bet is to record the audio of the refrigerators running for the length of the scene by itself, if that is possible. If you can't do that find another location to do that scene in.
 
I think Cedric is on the right track, especially if you combine it with Yeehaa's idea of writing it into the scene. The Hollywood adage of if you see it you should hear it works the other way around as well. Make sure we see the compressors at the start of the scene - perhaps the characters walk by them entering the scene and they start up as they walk past - in order to establish for the audience what the source of the noise is. Make sure you get some clean recording of the sound from the location where the dialog is taking place. Then lay it in under the scene where it's missing as part of the general ambience in order to avoid the unnatural sound of some lines having noise in the background while others don't. In other words, instead of a vain attempt to make it go away completely, make sure it's always there.
 
inverting phase to remove something pretty much never works especially if it's not a simultaneous recording. However you could in theory use the compressor noise as a noiseprint and remove it that way. But you will run up against the problem pointed out above, it's got a lot of overlap with voice frequencies. You can probably notch out a bit with a hum remover at the right freq. but the above suggestions are probably your best bet. I would avoid ADR if poss, it's a lot of work/money to get it right and anything less is VERY distracting for the audience. I would write it in and make it an artisic choice rather than a problem.
 
Peabody said:
Izotope RX is the solution when there is no other.
You can download a trial version.
Click to expand...

The trial version doesn't allow you to save the session but at least you would be able to tell if it can help or not before you purchase. I played with it on some tracks that I recorded near a large fountain in a park. I had a good ratio of dialogue to background sound but wanted to see if I could get rid of most of the water noise. Using the slow render working off of a noise print it did an amazing job of eliminating most of the water. This was without any prior eq and I did extreme noise reduction. The dialogue did have some artifacts so if I were to go less extreme on the processing it probably would have not affected the voice as much.
That being said, all of the other advice you've already gotten is better than relying on software to clean up your tracks. In your situation it may or may not help enough without damaging your tracks. One other thing you might do if the piece is scripted and the actors are consistent with their delivery is get the lines wild when the motors aren't running. The best time to do this would be after you've gotten the on camera takes you are happy with and before anything is wrapped. That way you could loop in and replace lines that have noise problems.
Regards,
Bernie
 
I don't like fixing in post either but recently a client wanted a shoot with roundtable interviews done in a courtyard. It was ringed by howling air conditioning motors and Izotope RX was the solution. Absolute magic IMHO!
 
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