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Problems With Sound Recorded With Lapel Mic

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Shitij Kohli
Problems With Sound Recorded With Lapel Mic
on Aug 4, 2013 at 2:42:25 pm

Hello,

I have recently filmed an interview and used my Sennheiser Lapel Mics (EW-112 P G3)...Used Zoom H4n as mixer.

The mics generally records amazing quality voice and has never given me trouble..however this time i observe that the voice quality is not that crisp...I am not sure how to explain this in professional terms (as i am not a sound guy but a Director, Editor).

The interviews were done in office and we there wasnt any sound in the room to cause noise.

On the day of interview when we had experimented with some settings of Lapel Mics...Please if anyone can throw some light as to what we did wrong.

Please kindly help me...This is a very important interview and i am feeling distressed.

PS:

I edit on FCP 7 and generally i used to take my wav files, make it +12 DB or +8 DB or +5 DB etc in FCP and i never used to hear noise in the background...but this time its giving noise...the voice recorded is not clear...I am not able t point in technical terms as to what seems to be the issue.

This file i have attached is 0 Db Into 3 Layers i.e. 3 layers of 0 Db sound -> Produced into wav.

Here is the file:

6367_soundsampleclip.wav.zip


Regards,
Shitij


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Richard Crowley
Re: Problems With Sound Recorded With Lapel Mic
on Aug 4, 2013 at 5:25:31 pm

I hear ambient noise, air handler rumbling, talking in the next room, traffic noise, not great signal-to-noise ratio (of indeterminate cause), and perhaps mic placement that causes a loss of high-frequencies ("chin shading", etc.) Impossible to really say as we don't know what microphone you are using or where you put it.

If you are boosting the level of the dialog track during editing, perhaps your recording level is too low. Especially if you said you were changing the settings on the transmitter(?) and/or receiver(?).

Sorry I don't know what you mean by "0 Db Into 3 Layers i.e. 3 layers of 0 Db sound". What exactly are you saying is "0dB"? What do you mean by "3 layers"? I hear only one person speaking. What other "layers" could there be?


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Shitij Kohli
Re: Problems With Sound Recorded With Lapel Mic
on Aug 5, 2013 at 5:16:03 am

Hello Richard,

Thanks for the reply.
I never knew the recorded voice had so many issues :-(

The settings in the transmitter were changed or tampered (and now no one remembers what)...Zoom H4n recording level for Mic was 75 (out of 100)....And we were into 4 channel mode of Zoom H4n.

In the 4 channel mode of Zoom H4n we record two layers of audio...First from MIC layer and the other from INPUT layer....We use the input layer in post-production, as that comes from the lapel mic receiver.

The MIC layer is recorded by Zoom H4n box...and generally this sound has lot of ambience noise, so we just keep it as a backup (in case something goes wrong)....For this, we keep the Zoom H4n box close to the interviewee as well.

The microphones used are called "ME2 lavalier"...they come with my Sennheiser Lapel Mics (EW-112 P G3).

http://www.bhphotovideo.com/c/product/618739-REG/Sennheiser_EW_112P_G3_A_EW...

The microphone (attached to transmitter) was placed on the neck tie of the interviewee, generally we place it on the shirt, but this time we placed it on the neck tie (just below the knot)...Is that Chin Shading???

I have also attached a snapshot of my FCP screen - here u'll get an idea of what i mean by 3 layers of 0 Db sound....that means i repeat the same layer of audio three times in FCP.

Could you kindly let me know what am i doing wrong and what points i need to take care in future....I would be really obliged.

I use ordinary headphones to monitor voice during shoots (and unable to spot the issue)...I know i would require high quality headphones, kindly let me know which headphones should be used.

Also for the current issue i went into soundtrack pro (Mac Software)...and reduced the background noise by first selecting an area where i could clearly hear the noise (Setting this as NOISE POINT) and then reducing that in the entire audio.

6368_audiovideofcpsettings.jpg.zip

Regards,
Shitij


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Richard Crowley
Re: Problems With Sound Recorded With Lapel Mic
on Aug 5, 2013 at 6:31:01 am

"The settings in the transmitter were changed or tampered (and now no one remembers what)."
Then first you must go back through the setup procedure and adjust both the transmitter and the receiver for proper levels.

"Zoom H4n recording level for Mic was 75 (out of 100)"
The setting of the control is not nearly as important as the indication of the RECORD LEVEL on the recorder.

"And we were into 4 channel mode of Zoom H4n."
I don't know what that means? There is only one channel coming out of the wireless receiver. What is being recorded on the other three channels?

"we record two layers of audio"
Sorry, I still don't know what "layers of audio" means?

"First from MIC layer and the other from INPUT layer"
Sorry, that doesn't make any sense. The MIC is an INPUT.

"We use the input layer in post-production, as that comes from the lapel mic receiver"
I don't know what that means, either. If you are recording the wireless receiver to channel 4 of the recorder, then you should be using only channel 4 for post-production. We still don't know what could be on the other three channels?

"The microphones used are called "ME2 lavalier"...they come with my Sennheiser Lapel Mics (EW-112 P G3)."
That is the microphone that comes with the transmitter/receiver. It is not noted for being high quality. It is adequeate and it gets you up and running, but you can replace it with almost any lav for better performance.

" this time we placed it on the neck tie (just below the knot)...Is that Chin Shading???"
Yes. "Chin shading" means that there is SOMETHING (usually the chin) between the mouth and the microphone. That significantly cuts down on high frequencies and makes the voice sound less distinct. Many lav microphones have rising high frequency response to compensate for chin-shading.

"i repeat the same layer of audio three times in FCP"
WHY? That doesn't make any sense. Your whole description of recording channels and editing "layers" is not the typical way we record and edit. You are doing many strange things and they may be contributing to your poor results.

Unless you have good quality headphones which block ambient sounds, you really don't know what you are recording. It would be like framing and focusing without looking at the viewfinder. However, DO NOT use "noise-cancelling" headphones because they will disguise the noise you are recording!

"selecting an area where i could clearly hear the noise (Setting this as NOISE POINT) and then reducing that in the entire audio"
That is only something you should use if nothing else works. It typically causes bad distortion to your audio and it should be avoided if at all possible. I would use that method only as a last resort.


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Shitij Kohli
Re: Problems With Sound Recorded With Lapel Mic
on Aug 6, 2013 at 6:19:22 am

Thank You Richard for your timely help...I have hired an Audio Engineer to help me out of this.
I will definitely improve my knowledge in this field.

Regards,
Shitij


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