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Old February 11th, 2006, 11:50 AM   #1
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How much can I do in post

Hi Guys,

Okay I'm just wondering if any of you more experienced sound guys can tell me how much I can do in post with regard to fitering out unwanted background doise and and what I can do with effects. I've just done another test with one of my g2 evolution wireless setups and the mics are picking up a fair bit of ambient noise. I'm not sure if I'm useing them to there optimum capacity. I think I may have them running too sensitively? However, I have the sensitivity on the transmitter set to -30db which is the lowest for that unit I believe. I have the reciever on camera going into one of the XLR inputs. I have the camera set to auto level. I could turn it down in manual mode but it then sounds to soft comapared to the amount of ambient sound that it cuts out. I also have the Me2 mics with this set which I think is the less directional of the two options that come with this kit, the other being the Me4. Maybe I need a better or different mic. Finally, if I can't get another mic I'm just wondering how much I can do with these issues in post with (a) a standard NLE like pp1.5 and (b) with other seperate sound packages like Pro Tools, Adobe Audition or Sonic Foundary (Ithink that's the sony one but I could be wrong). My main concern is that for my upcoming project I will be out on location and I'm now wondering if I'm goinjg to pick up the voices of passers by with this kit whilst I'm trying to record actors dialogue. Sorry it's such a long post but I would greatly appretiate any input.

Regards Greg C

P.S. Ty Ford, I had a look on your site earlier. In the past I've had trouble viewing stuff but it seemed to work okay today. Just wanted to say that's a great sight with some really interesting stuff (that's for if you've read this of course)

Thanks again Guys
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Old February 11th, 2006, 01:00 PM   #2
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The ME2 is an omni-directional mic which means it picks up equally well all around. The ME4 is cardioid, which means it rejects sound coming from behind where it's pointed. Depending on how you position it, the ME4 is likely to give better rejection of unwanted ambient noises. Your user manual recommends the ME2 for presentations and other low ambient noise environments (TV studio for instance) and the ME4 for ENG and other noisy situations.

Automatic control on the level in camera is a bad idea. When your talent isn't speaking, the camera will boost the gain looking for sound that isn't there, making any background sounds, hiss, etc louder in the process. Then when your talent does speak, it'll start very loud, perhaps even overloading, and then fade as the camera turns the volume back down again to normal levels.

Put the mic on the talent and do a sound check. Adjust the transmitter sensitivity so its meter peaks on the very loudest sounds and then back it off a hair. Set the camera to manual control and set the knob to about 60% full up. Adjust the receiver output to the camera so you are getting about -12 dbfs indicated level on the camera meter with normal level sounds in the mic. That should put you in the ball-park for optimum settings.
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Old February 11th, 2006, 02:09 PM   #3
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Quote:
Originally Posted by Steve House
Automatic control on the level in camera is a bad idea.
I agree with Steve. It is extremely important to use manual mode. Automatic gain control will ruin your audio and make your editing in post a nightmare. Just turn it off and forget itís there.

Quote:
Originally Posted by Steve House
Adjust the transmitter sensitivity so its meter peaks on the very loudest sounds and then back it off a hair.
Maybe even two hairs. The key here is that itís much easier to normalize weak audio and make something good of it, then to try and restore distorted audio that is overdriven. Always err on the side of too low. You can always raise it in post and use noise reduction to get rid of ambient noise that gets raised along with it. There is very little you can do with clipped audio that is too loud. (i.e., you can lower it all you want, the clipping distortion will still be there)

One habit to get into if you are only using a single mono mic is to record it into both channels of your camera simultaneously but keep one channel volume lower than the other. Then if one channel does distort, you can always use the other channel for that passage.

As for filtering out unwanted noise in post, Sony Noise Reduction is excellent for this. BIAS Sound Soap 2 is also very good and simple to use. These are both plug-ins that will support any DirectX host. Sound Soap also supports VST hosts. As long as you have a few seconds of just the ambient noise for them to sample, they will do a good job of removing it. Always use it several times with small amounts of removal rather that trying to remove all the noise at once.

~jr
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Old February 11th, 2006, 08:25 PM   #4
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I second the advice given so far.

I also highly recommend the Sony Noise Reduction 2.0. However, road noise is very hard to eliminate.

In any case, it takes some skill and practice to use Noise Reduction 2.0 to eliminate noise.
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Old February 12th, 2006, 08:28 AM   #5
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many thanks

Thanks Guys,

as usual some really great info there. I'm a bit dissapointed as I explained what I wanted to do with the mics to the dealer and he said me2. I now wish I'd gone with my instinct and got the me4. Do any of you guys know how forgiving the me4 or cardiod in general might be of head turns though.
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Old February 12th, 2006, 09:14 AM   #6
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I recommend that you run another test.

Set the camera on manual.

Ensure that the ME2 is close to the sound source.

Set the sensitivity in the Sennheiser G2 to various levels for your test.

I don't know how noisy of a situation you will be in, but the ME2, placed close to the source should generally work. I recommend that you give the ME2 another try before buying the ME4 or other microphone.

Generally the ME2 is a good overall choice.
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Old February 12th, 2006, 12:23 PM   #7
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Muchos Gracias

Thanks Dan,

That's really what I wanted know. i.e. that if I stick with this set up I should eventually get something half usable. It's difficult when your testing stuff like this as a bit of a newbie as I've got no other experience with wireless set ups to measure against. I'm gonna take the tips posted on this thread and try some more tests.

Thanks again Greg C
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