Fan Noise?

David G. Smith

David G. Smith

Steak Knife Member
I just shot a thing and ended up with a loud fan noise, from a refrigerated beverage case, on my main sound track. It was totally my fault as I OKed very poor mic placement. Live and learn on that for future reference, but what are my options now? Would I be able to at least minimize the fan noise by limiting specific frequencies? It seems to me that the fan noise falls in the frequency range of the human voice so I am a little skeptical about that. Any other suggestions? Would the Bias product "Sound Soap" (LE) be able to help in a situation like this? Any help will be greatly appreciated. Thank you.
 
We are limited to response in broad (and practically useless) generalities without hearing a sample.

If the noise is concentrated in one or two discrete frequencies (as a small DC fan) then you may be able to "notch" it out (depending on what affect that has on the dialog).
But broadband noise is practically impossible without expensive software in the hands of experts.
 
In post, try isolating a short section of just fan noise. Extend or loop it on a separate track, then put that out of phase with the original track.

Give that a shot it might be acceptable, especially on a deadline.

Cheers.
 
Richard Crowley said:
We are limited to response in broad (and practically useless) generalities without hearing a sample.

If the noise is concentrated in one or two discrete frequencies (as a small DC fan) then you may be able to "notch" it out (depending on what affect that has on the dialog).
But broadband noise is practically impossible without expensive software in the hands of experts.
Click to expand...

I will work on getting a sample together for posting.

Allan Black said:
In post, try isolating a short section of just fan noise. Extend or loop it on a separate track, then put that out of phase with the original track.

Give that a shot it might be acceptable, especially on a deadline.

Cheers.
Click to expand...

Yeah, deadline is not really an issue. The project is a longitudinal documentary where I am covering the creative dynamics of the development of a play that will not be fully produced until next July. The event that I just shot is the first pubic performance, done as a public space play reading. The whole thing is a no money run and gun deal and the audio is going to be a big challenge.
 
Just shot a short on the BM Pocket in a gas station, where they had a gazzillion of fridges with different hum, and we where not allowed to turn them off.

http://www.youtube.com/watch?v=v5gAq_eN1ks

Drove me nuts, when mixing the audio, since I would be okay with hum, when you have a huge fridge in the image, but at every cut we had a different hum that really sucks.

I was able to clean it up to some degree with an Isotope plugin, but a guy from UK (DuckSound) jumped in and really cleaned up the mess for me, without hurting dialog.

So yeah, it's doable, but you need the right tools and a ton of experience.
 
The only reasonably affordable tool that has much of a chance is Rx by iZotope. Cedar and TC Electronics have tools but they are $$$ to $$$$$$$$$.

Not sure about TC but Cedar is excelent, but not many on this list are ready to drop $5,000 to $15,000 on a noise reduction tool.

By far the cheapest option is to pay someone who has the tools and knows how to use them.

Sound Soap is probably not going to be great for this nut? Give it a try who knows. Still the low priced version is $99 and you might well find someone willing to run your files for less (depending on how much running time we are talking).

And be prepared to still have some there. If it's steady and the perspective doesn't change AND it's not hitting the vocal range too much then maybe you really can get it pretty clean. generally though it's hard to get it all out with out having a hard hit on the dialog.

I just did this for a friend and I did multiple versions so they could choose the one they thought was the best trade off between no humm and un affected dialog.
 
GaryNattrass said:
We had a sunlight laundry next door to one of our street sets for a soap I did in the 90's called family affairs and we used the TC Elctronics TC6000 with backdrop to do this sort of filtering: http://www.tcelectronic.com/backdrop-system-6000/
Click to expand...

Noiz2 said:
The only reasonably affordable tool that has much of a chance is Rx by iZotope. Cedar and TC Electronics have tools but they are $$$ to $$$$$$$$$.

Not sure about TC but Cedar is excelent, but not many on this list are ready to drop $5,000 to $15,000 on a noise reduction tool.

By far the cheapest option is to pay someone who has the tools and knows how to use them.

Sound Soap is probably not going to be great for this nut? Give it a try who knows. Still the low priced version is $99 and you might well find someone willing to run your files for less (depending on how much running time we are talking).

And be prepared to still have some there. If it's steady and the perspective doesn't change AND it's not hitting the vocal range too much then maybe you really can get it pretty clean. generally though it's hard to get it all out with out having a hard hit on the dialog.

I just did this for a friend and I did multiple versions so they could choose the one they thought was the best trade off between no humm and un affected dialog.
Click to expand...

Yikes, yeah the professional tools for this are expensive. Looks like I am going to be looking for a good sound post house.
 
I had SoundSoap LE and it was pretty much useless. I tried it on a fridge in a scene and it just destroyed the dialogue. My personal experience is the Cedar stuff is what really works, but I've never used the Izotope stuff.
 
Sound Soap is OK on hiss/hum and has some de clicking that works OK. Things like refrigerators are VERY hard because they are so complex and often changing. iZotope is on a par or better than the Waves denoiser. And a small fraction of the cost. Cedar is great but you have to have some pretty serious need to justify the cost.

The most cost effective and best solution is to listen when you shoot and not have to try and "fix it in the mix" in the first place.
 
Allan Black said:
Try that first, cheap and quick.

Cheers.
Click to expand...

This has close to zero chance of helping but it is quick and cheap. Just don't get discouraged if it doesn't really do anything or gives you strange "space" sounding effects.

BTW the reason this is so unlikely to work is that for it to work you would have to have a sound that never changed perspective or speed or tone. Then you would have to phase in the sample (for each cut). then you could invert it. Anything else and your hitting and missing the sound you want to remove and you will get phasey artifacts.

Most noise reduction plugins work a bit like this (they use a "noise print" to create a bank of expanders to subtract the noise print from the original) and have been tuned to help avoid the artifacts, so you are much better off just going to the right tool.
 
Get a free copy of Audacity. It does for sound what Neat Video does for images.

You select an area that has the noise, it samples it, then gets rid of the noise in that pattern. Sometimes you need to select smaller areas for a second pass. It's saved me a couple of times.

http://audacity.sourceforge.net/download/
 
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