Seeking advice for improving sound on a shoot that just happened

A

ARRIguy

Member
As I expected we got lousy sound.

After reverb and russhshsh of the air conditioning some speech was barely intelligible through the headphones. (By ear going without going through the camera mic the sound was OK). Someone else was in charge and time was very limited so I couldn’t suggest improvements. But if I’m in charge of shooting a similar situation I want to do better. Tell me what you would do.

The location and constraints:
A carpeted room about 30 feet square, white board for the lecturer on two sides of the room and plaster on the other sides. Drop ceiling about 10 feet high with six 2 1/2 foot diameter air-conditioning vents and about as many fluorescent light fixtures with large removable acoustic panels. One PD 150 was shooting 20 student/participants were arranged behind 4 long desk/counters that filled 2/3 of the room. A second PD 150 was in a back corner shooting the lecturer who was alternating between the two walls of white board.

The lecturer was not a problem as the producer stuck a radio lapel mic on him. The students were recorded from static position from a front corner of the room (a constraint) with the supplied on camera (PD 150) mic. The client was very conscious about not disturbing the student/participants so no boom micing of them would be permitted. Other than putting a mic in front of every participant and having a separate sound person (no budget for these) what would work better for recording the questions from students .

Assume the producer could afford an extra a.) $50 a day or b.) $100 a day to rent additional equipment to improve sound.

Suggestions???
 
Awareness is the 1st tool for good sound, without it good electronic tools can't get decent results.

Reverb & air conditioning can be overcome. Turn off AC, either dampen the room with Sound absorbing material and carefully aim microphones toward the source or simply move the mic as close as possible.

Most audio problems can be solved by properly getting the mic to a distance that overcomes reflections ( that often means close). There is no such thing as a zoom mic so if the students need to be heard then there must be a mic within close speaking distance or you'll end up recording as much reflected sound as originating source.

Settings: use the Goldielocks Principle: not too soft, not too loud, set it in the middle, ahhh that's just right.

Testing, is the other forgotten Secret Veapon hidden from the world in Der Furher's bunker. Test until you find the outcome you're looking for.
 
For good sound, you really need to get your mic as close to the source as possible. But the right type of mic will also help you.

The mic on the PD150 is probably omni directional, which will pick up everything in the room. If you had a shotgun mic (super cardioid) on the camera, it would help filter out noise from the side. Better yet, you can mount it on a boom at the camera location just to get a little closer to the speakers. Another solution would be to put an omni mic on each table to get closer to the speakers.

You can also filter out the air conditioning noise in post.
 
I'm with sumfun on this one... on-camera mic will never produce the quality of audio that you'll desire, and will always have too much background/ambient noise. I would suggest either planted lav's on the table, or perhaps a boundary mic (the kind they use for conference calls). Get the mic close to the source and you'll have a much better signal-to-noise ratio.

As far as A/C filtering in post, a lot can be done with that, so your audio may not end up as bad as it seems now. With equalization you can pull out notches of sound, and drop off the low end and probably reduce the A/C noise quite a bit. There's also programs like Sony Sound Forge Noise Reduction, although I don't think I've been able to get a fully "natural" sounding soundtrack with that tool yet... someone who knows how to use it may do better!
 
Barry, Sound Forge probably has the best noise reductions software out there. With Waves and then SoundSoap pro following it. I often rue the day I became a Mac Addict simply because of Sony's Noise Reduction!

Why do you think it doesn't sound natural? Are you pulling so much out that you're changing how the dialog is produced or is it "too clean"? Have you tried adding in controlled room tone after cleaning?
 
These audio Noise reduction tools can work if the freqs are a distance from the source you want to preserve, otherwise they start to seriuosly disturb the naturalness of the recording. It's best to always get good sound 1st. That means turn off or dampen the AC.

Recording studios and sound stages are constructed to create environments where good sound is possible. The walls cost a lot of money for good reason.
 
As 10s says, the dialogue can start to get quite "robotic". It's infinitely better to get it right when recording. We always turn the AC off whenever possible, although of course that's not always possible.
 
Even the best noise reduction tools do not eliminate noise that shares the same frequency and time as the speaker; it just hides it so your ears focus more on the voice then the noise behind it.

Important to know this if you are thinking of "fixing it post". If there is not a high enough ratio of noise to dialog then nothing (using today's technology) is going to make it useable. So it becomes very important if you can't eliminate a noise source that you get your mic as close as possible to the speaker in these circumstances.

A camera mounted mic parked several feet away will not work in this case.

In the future you might try and use some PZM mics. If the students are doing a Q&A (as opposed to group dicussions)you could use a wireless handheld mic that is passed to whoever wants to ask a quesion (ala daytime talk shows). This can kill some spontaneity but sacrifices must be made when you are under hard budget constraints.

Best o luck
 
Barry,

Don't get me wrong, I don't think Sony's Noise Reduction could fix ARRIguy's problem, but as far as noise reduction software goes, I think Sony's is top notch. Maybe I'm just used to working on better audio, so I'm not really trying to "fix" things as much as sweeten them. Although I did do a short for someone who had more noise than he should have (albiet low) and I was able to use Waves plugs (along with directly modifying the waveform) to get rid of it and still keep the audio sounding natural.

10s, I've worked and recorded in some very nice studios, so I know what the walls are worth :thumbsup: and I full appreciate the importance of capturing good audio. I was just surprised that Barry didn't think Sony's noise reduction was very good. I assume he captures excellent audio and only needs to do a bit of cleaning here or there and for that I think Sony's noise reduction is superb.

Also, it's important to try and capture the noise itself without dialog. This way the software can best analyze what it needs to remove. Oh, and I don't find it works well to try and remove the noise in one pass, but rather it works better to go back a few times getting more and more in each go. This will help to prevent some of that robot sound you're getting.

Matt
 
I have students in my audio classes take mini disc recorders and go out to a busy interestion in a city and record a given script. They then bring the track back into Adobe Audition, we isolated the noise, create a wave profile and then extract the profile from the track so it's completely elminated. What is left is often a very nice sounding conversation without the sound of trucks & cars going by, it's pretty amazing! but this is a trial by error situation. Because the freqs are so different than the human voice there isn't any freq reduction of the voices, only the traffic. Therefore, testing prior to production efforts is key.

20 years ago we dreamed of this suff..now everyone has it. So I suspect that oneday HD cameras will come as an accessory with Barbie dolls at Toys R Us. :)
 
Hold on, I think Sony's noise reduction plug-in is amazing. I just haven't been able to get it to work the miracles that I wish it was capable of.
 
Barry_Green said:
Hold on, I think Sony's noise reduction plug-in is amazing. I just haven't been able to get it to work the miracles that I wish it was capable of.
Click to expand...

Sorry Barry, I don't understand your post. Would you please explain? What noise reduction plug in? Would it work to take out the terrible reverb and the AC rushsshsh recorded on the tape?

PS I would have taken it as a joke if you included a smiley but since you didn't...
 
10s said:
Awareness is the 1st tool for good sound, without it good electronic tools can't get decent results.

Reverb & air conditioning can be overcome. Turn off AC, either dampen the room with Sound absorbing material and carefully aim microphones toward the source or simply move the mic as close as possible.

Most audio problems can be solved by properly getting the mic to a distance that overcomes reflections ( that often means close). There is no such thing as a zoom mic so if the students need to be heard then there must be a mic within close speaking distance or you'll end up recording as much reflected sound as originating source.

Settings: use the Goldielocks Principle: not too soft, not too loud, set it in the middle, ahhh that's just right.

Testing, is the other forgotten Secret Veapon hidden from the world in Der Furher's bunker. Test until you find the outcome you're looking for.
Click to expand...

I agree with all that you've said 10s. I'm going to be offering my own solution to the problem we had for criticism in another post. It will include some of the points you made here plus some others. Thanks for your response.
 
Sonic Foundry offered an amazing plug-in for Sound Forge called Noise Reduction. Basically it let you sample background noise (such as the rumble of an air conditioner), and then it would go through and try to eliminate that noise pattern throughout your audio. And it works. But I always found that the resulting audio, while de-noised, made voices sound robotic and unnatural.

No plug-in can reduce echo/reverb. And you can probably get rid of a lot of the air conditioner noise with notch filters in your EQ. The noise reduction filter may help, but I've never been able to get it to work without side effects.
 
You might take a look at the Waves plug-ins Restoration Bundle for very positive results in removing unwanted pops, clicks, clothing rustles, shirt noise, etc.

Downside is the same thing as Barry mentioned--they can make voices sound very bizarre in certain circumstances--but it is possible to fix many things with very acceptable results.

Maybe you could find a young, budding sound editor to help out with some of this at reduced rate. Locally there are a few small rock-band-type recording studios that also have them--so maybe you could find a small project studio looking to get into films.

brian wells
 
10s said:
I have students in my audio classes take mini disc recorders and go out to a busy interestion in a city and record a given script. They then bring the track back into Adobe Audition, we isolated the noise, create a wave profile and then extract the profile from the track so it's completely elminated. What is left is often a very nice sounding conversation without the sound of trucks & cars going by, it's pretty amazing! but this is a trial by error situation. Because the freqs are so different than the human voice there isn't any freq reduction of the voices, only the traffic. Therefore, testing prior to production efforts is key.
Click to expand...

Hey 10s, I use Adobe Audition, too, and that noise reduction filter really does come in handy sometimes. But I've never been able to reduce the noise completely and still have nice sounding conversations. If I reduce the noise completely, then the voices sound electronic and I usually get a reverb. So usually I just reduce noise by 30-50%. I've tried boosting the noise reduction at <100Hz and >10kHz, but this only has a minor effect. Traffic noise seems to cover a wide frequency range and it varies over time, so it's difficult to completely get rid of it.

Could you give me some pointers as to what you're doing? I know it's trial and error, but it would be a good starting point.
 
Thanks for feedback Barry and thisiswells.

The editor for this piece will be someone who uses FCP and Premier on a Mac. Will these plug ins work with either of these platforms?
 
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