Help with a Buzzing

A

ASchear

Well-known member
Hey guys,

Wondering if you've ever dealt with anything like this -

I am working on audio on my film that I shot with my 35mm adapter. It's a spinning glass model, so there is a motor inside that made a buzzing noise. My sound guy decided to use my Sennheiser ME66 with a cardioid instead of the ME67 true shotgun, so now the buzzing is all over the film, and it wasn't noticeable until we imported into Protools.

We've tried removing it by frequency, but cannot do it to any considerable amount without losing voice tone (especially on the young actress). We even had a sound engineer look at it and he told us we could not take it out by EQ.

I was wondering if there is a way to put a threshold on what sound we hear, such as - anything BELOW X dB is silent. The buzzing is much softer than the voices, but I honestly think it can be eliminated with the right know how.

I was able to achieve a little success by lowering the dB level in the mixer to -30 in Media Composer and then layering the track 10x to increase the volume. This helped considerably in my opinion, but did not eliminate the buzzing completely. If anyone wants to do tests, I can e-mail a sound file, just PM me for it.

Thank you for any help you can offer! ADR is an option, but I'd rather not if we don't have to.

-Andrew
 
Seriously, if the buzzing was so loud it was being picked up by the mic boomed over the talent, the difference between using a ME66 and an ME67 would have been minimal. What the sound guy shoudl have done was say the sound was going to be crap until the adapter was repaired (I've been on several shoots with these adapters and they were never loud enough to bleed into the audio). Unless your camera was on top of the talent, a properly operating adapter should be nearly inaudible a few feet away.

My tool of choice for this kind of surgery is Izotope RX. It takes some practice and time but is pretty dang effective at cleaning up things like this.

Have you fixed your 35mm adapter?

ASchear said:
Hey guys,

Wondering if you've ever dealt with anything like this -

I am working on audio on my film that I shot with my 35mm adapter. It's a spinning glass model, so there is a motor inside that made a buzzing noise. My sound guy decided to use my Sennheiser ME66 with a cardioid instead of the ME67 true shotgun, so now the buzzing is all over the film, and it wasn't noticeable until we imported into Protools.

We've tried removing it by frequency, but cannot do it to any considerable amount without losing voice tone (especially on the young actress). We even had a sound engineer look at it and he told us we could not take it out by EQ.

I was wondering if there is a way to put a threshold on what sound we hear, such as - anything BELOW X dB is silent. The buzzing is much softer than the voices, but I honestly think it can be eliminated with the right know how.

I was able to achieve a little success by lowering the dB level in the mixer to -30 in Media Composer and then layering the track 10x to increase the volume. This helped considerably in my opinion, but did not eliminate the buzzing completely. If anyone wants to do tests, I can e-mail a sound file, just PM me for it.

Thank you for any help you can offer! ADR is an option, but I'd rather not if we don't have to.

-Andrew
Click to expand...
 
If you can hear the buzzing during the actual dialogue, it could be more of a distraction to get rid of it between lines than to just leave it alone. There is an Izotope plug-in (someone help me out on the name of it here) that supposedly does a good job of getting rid of noise, but I haven't used it, so I can't comment on how well it works. Worst case scenario is you'll need to ADR the dialogue.

EDIT: gpforet posted before me. Izotope RX is what I was thinking of.

Was anyone monitoring the audio during the shoot?
 
Wasn't the sound guy monitoring the audio while you were shooting? Recording audio without monitoring on good, isolation headphones is exactly like framing and focusing without looking at the viewfinder! If the sound guy heard the equipment noise, why didn't he speak up at the time? If the sound guy heard the equipment noise, why didn't he consider using a more directional microphone or a different microphone position etc, etc. If the sound guy didn't hear the noise during production, then he wasn't doing his job.

I'm not really buying the excuse that it "wasn't noticeable" until imported into Protools. You need more proficient help recording sound. It was the sound guy's primary job to STOP the production if this kind of a problem was happening. There could have been several different reasons why you would think it "wasn't noticeable", but they are all under the purview of the sound guy to fix on the spot, or else stop the production until they can be remedied.

As far as remedial help after the fact, I can typically significantly reduce that kind of noise in Adobe Audition with the Noise Filter which takes a "clean sample" of the noise and then mathematically removes it from the recording. Note that this is NEVER perfect and is never a proper substitute for recording the sound right in the first place.

Hopefully, this will be a good learning opportunity for the importance of sound on your next production.
 
Yep, the sound guy needs to be tethered to the camera, if recording sound into the cam. And the sound guy takes precedence over the director if a split or IFB is not available. I hated having the director grab my cans and say "I will monitor the sound". Told him, if he really wanted to do that, I would let him run the audio too. Cans given back.
 
Wow, thank you guys for all your posts. It was a problem with the monitoring during production because we had such a small crew and a lot of times I was stuck operating camera and monitoring because we literally had no one else to boom.

It's been a great learning experience toward how important sound is to the film, and next time I think I'll find someone who can really be dedicated to it for the entire shoot. My lens adapter is custom made, and the motor is just loud - so I do believe the microphone could have made a difference. And in reference to the Media Composer versus Pro Tools deal - my ears really are a witness to it. I can put my computer speakers as loud as they'll go in MC5 and it's fine. But in the sound lab where these guys are working on Pro Tools, there is a major difference. Even on shots where I could not hear any buzzing whatsoever, it's audible there.

As for the lens adapter, I'm going to probably cover the inside of it with some type of carpet or other insulation. I'll also insulate the motor more because, a major factor I felt was the motor vibrating against the metal of the adapter. I dampened this with some tissue paper, but I think I could do it a lot more. After all this, I'll also consider wrapping it in a blanket on my next shoot and replacing a motor that is more powerful so it doesn't need to run at full capacity to work and thus will be quieter.

Again, thank you guys so much, and if there's anything else, still let me know! I'll be testing these solutions.
 
This makes a little more sense now. You were using a home-made, knowingly loud adapter. Here are the two polar patterns for the ME-66 vs. the ME-67. The 66 is on the left, the 67 on the right. If anything, the ME-67 shows less rejection for sound from the rear, so, in effect, the ME-67 would have made things worse, not better. This is typical of shotgun microphones. Looks like your sound guy made the right choice but simply could not overcome the noise coming from your adapter. It comes as a surprise to many that in some cases, a shot shotgun is the better choice than a long shotgun.

ME66_polar.jpg
ME67_polar.jpg


ASchear said:
Wow, thank you guys for all your posts. It was a problem with the monitoring during production because we had such a small crew and a lot of times I was stuck operating camera and monitoring because we literally had no one else to boom.

It's been a great learning experience toward how important sound is to the film, and next time I think I'll find someone who can really be dedicated to it for the entire shoot. My lens adapter is custom made, and the motor is just loud - so I do believe the microphone could have made a difference. And in reference to the Media Composer versus Pro Tools deal - my ears really are a witness to it. I can put my computer speakers as loud as they'll go in MC5 and it's fine. But in the sound lab where these guys are working on Pro Tools, there is a major difference. Even on shots where I could not hear any buzzing whatsoever, it's audible there.

As for the lens adapter, I'm going to probably cover the inside of it with some type of carpet or other insulation. I'll also insulate the motor more because, a major factor I felt was the motor vibrating against the metal of the adapter. I dampened this with some tissue paper, but I think I could do it a lot more. After all this, I'll also consider wrapping it in a blanket on my next shoot and replacing a motor that is more powerful so it doesn't need to run at full capacity to work and thus will be quieter.

Again, thank you guys so much, and if there's anything else, still let me know! I'll be testing these solutions.
Click to expand...
 
I can typically significantly reduce that kind of noise in Adobe Audition with the Noise Filter which takes a "clean sample" of the noise and then mathematically removes it from the recording.
Click to expand...

I've grown very fond of Audition's NR tool. At least in certain situations. It doesn't always work depending on the type of noise you're trying to remove, but it's pretty darn good. Having said that, it's hard to beat a Cedar NR system, but they're way over-priced.
 
gpforet said:
This makes a little more sense now. You were using a home-made, knowingly loud adapter. Here are the two polar patterns for the ME-66 vs. the ME-67. The 66 is on the left, the 67 on the right. If anything, the ME-67 shows less rejection for sound from the rear, so, in effect, the ME-67 would have made things worse, not better. This is typical of shotgun microphones. Looks like your sound guy made the right choice but simply could not overcome the noise coming from your adapter. It comes as a surprise to many that in some cases, a shot shotgun is the better choice than a long shotgun.

ME66_polar.jpg
ME67_polar.jpg
Click to expand...

Great insight - I've never seen these patterns but have always wondered. I do wonder though, whether the extra space near 90 degrees on the 66 diagram would be what caused the problem. If I'm reading them right, microphone pointed up parallel to the page, anything in the rear wouldn't have mattered as much as anything at 90 or 270, since we were booming from above with the camera in front. I do understand, though, how the extra pattern at 180 can help offset what's being picked up on the side. If only we could combine the two!

It being the right choice, though, I think was completely chance. Him not switching microphones I think was more because of laziness.

Do you have any other suggestions for the adapter and muffling it? They would probably be extremely helpful, I'm no sound expert.

On a brighter note, although I did kind of compromise sound here, both the sound engineer we showed it to and one of the guys who helped with building the sound for outdoor scenes thought we shot on film. :)
 
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ASchear said:
...And in reference to the Media Composer versus Pro Tools deal - my ears really are a witness to it. I can put my computer speakers as loud as they'll go in MC5 and it's fine. But in the sound lab where these guys are working on Pro Tools, there is a major difference. Even on shots where I could not hear any buzzing whatsoever, it's audible there.
...
Click to expand...

I think that is more a testament to the importance of proper monitor speakers in your edit/mix room than it is a difference in the software. I'll wager the ProTools facility has proper studio monitors and it wouldn't be surprising that you can hear things in the tracks there that are inaudible on computer "multimedia" speakers no matter how good they claim to be.
 
Good point about the 90 degree rejection. If this was boomed outdoors or in a large indoor space with high ceilings and low reflectivity then I, too, would be more prone to grabbing a mic with a tight pattern and long interference tube. If the shot was indoors with a low ceiling and close sidewalls, I'd grab a mic that either doesn't use interference tubes or the shortest intereference tube in the kit. Of course, if the boom op is not monitoring the sound, then whi;e experience may help with mic selection, aiming a mic without headphones is just like framing a shot without a viewfinder. You'll get close but not optimal.

As far as how to quite down your adapter, I have no idea. As a sound guy, I cring when being called for a red shoot because of how noisy the fan is.

ASchear said:
Great insight - I've never seen these patterns but have always wondered. I do wonder though, whether the extra space near 90 degrees on the 66 diagram would be what caused the problem. If I'm reading them right, microphone pointed up parallel to the page, anything in the rear wouldn't have mattered as much as anything at 90 or 270, since we were booming from above with the camera in front. I do understand, though, how the extra pattern at 180 can help offset what's being picked up on the side. If only we could combine the two!

It being the right choice, though, I think was completely chance. Him not switching microphones I think was more because of laziness.

Do you have any other suggestions for the adapter and muffling it? They would probably be extremely helpful, I'm no sound expert.

On a brighter note, although I did kind of compromise sound here, both the sound engineer we showed it to and one of the guys who helped with building the sound for outdoor scenes thought we shot on film. :)
Click to expand...
 
Steve House said:
I think that is more a testament to the importance of proper monitor speakers in your edit/mix room than it is a difference in the software. I'll wager the ProTools facility has proper studio monitors and it wouldn't be surprising that you can hear things in the tracks there that are inaudible on computer "multimedia" speakers no matter how good they claim to be.
Click to expand...

*buys Studiophile monitors*

I've actually been wanting to for a while and it would be a very interesting test. I'll probably invest with my tax return coming.
 
To anyone that was interested, I finally ran a trial of Adobe Audition tonight to see what I could get. Having no really audio knowledge and a limited understanding of the program, I applied a couple of filters and fiddled with a couple of settings until I found something I was happy with. I was extremely surprised at how easy it was to do, especially after all the people at school who told me my only option was to dub everything. A testament to Adobe Audition! Seems like a solid program.

Here are the before and after files, for anyone who is interested. I cannot thank you guys enough for your help with this issue. There will be a special place in the credits and in my heart for y'all.

Here's the files: http://www.mediafire.com/?b24hmfwn4w5xzgf

Let me know what you think! My opinion is that the buzz is still a tiny bit there, but unless you're listening for it, it won't affect the piece.
 
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