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-   -   Hiding Lav Mic (http://www.dvinfo.net/forum/all-things-audio/502462-hiding-lav-mic.html)

Tom Morrow November 8th, 2011 10:00 AM

Hiding Lav Mic
 
After five days of hiding lavs on actors, and trying various approaches to minimizing rustling, I've pretty much settled into the following as best practice:

Wrap the microphone capsule with a bandaid, rolled around the barrell so the bandaid covers all edges but does not block the sound port on the end (Side-ported tram lav mics need not apply).

Then using one or two long pieces of bandage tape (not as stiff as gaffer tape and pulls off less hair), I loosely tape the bandaid-covered capsule to float in the middle between the person's breasts. The tape suspends the capsule forming sort of an isolation mount, and the bandaid blunts any collisions of the capsule into the body while moving. The key is to get it suspended so it's just off the skin, but also away from the shirt fabric.

This method works on men and women... with women I have them run and place the capsule and wire, whereas with men I just reach under their shirt to place it. The big surprise is how much room men have there... athletic buff guys have that part chiseled out, and guys who don't work out have big man-boobs with a nice big valley between. I've heard that some people have more space to hide a mic by their shoulders, but haven't seen it in the wild.

There was a thread in the past on hiding lavaliers and I don't want to rehash all the possibilities in this thread, but any comments are welcome.

Garrett Low November 8th, 2011 10:53 AM

Re: Hiding Lav Mic
 
Don't forget the Broadcast Loop.

BTW - was listening to this weekend's shoot and the sound was quite good considering the surroundings and amount of ambient noise we had to deal with. Good working with you Tom.

-Garrett

Deborah Gallegos November 8th, 2011 12:40 PM

Re: Hiding Lav Mic
 
Quote:

Originally Posted by Garrett Low (Post 1695350)
Don't forget the Broadcast Loop.

???

Deborah

Steve House November 8th, 2011 01:31 PM

Re: Hiding Lav Mic
 
Quote:

Originally Posted by Deborah Gallegos (Post 1695397)
(Broadcast Loop) ???

Deborah

The "Broadcast Loop" is a strain relief loop in the cable of a lav just below the capsule. The cable comes down from the mic head an inch or so, turns and loops up through the hinge at the other end of the clip, then loops over again and is clipped between the mic clip and the inner side of the shirt on the opposite side of the fabric from the mic head. If you just let the wire dangle straight down from the mic it will transmit every tiny vibration right into the mic capsule.

Warren Kawamoto November 8th, 2011 01:35 PM

Re: Hiding Lav Mic
 
How do you prevent picking up a person's heartbeat with this method? When I tried it several years ago, I got a low frequency kathump...kathump...kathump... throughout the entire shoot which can't be heard through headphones, but comes out clearly in post.

Bill Davis November 8th, 2011 02:04 PM

Re: Hiding Lav Mic
 
If you've got too much heartbeat, it likely means that you've rigged the mic in such a way that it's element is obstructed so badly that you're applying way too much gain.

On a properly rigged mic, the signal to noise ratio should be such that any heartbeat will be so far under the signal floor that it won't be a problem

If you're faced with this after the fact because someone didn't notice and fix the problem in the field, a simple high pass filter should clean things up (unless, of course, the person speaking is James Earl Jones and their voice is down there close to the "heartbeat" part of the audio spectrum. ; )

Hope that helps.

Brian P. Reynolds November 9th, 2011 02:54 PM

Re: Hiding Lav Mic
 
Here is a link to more good advice on Lav mics....
Location Sound Corp.

Tom Morrow November 10th, 2011 05:26 AM

Re: Hiding Lav Mic
 
I actually did some experimenting a month or so ago, tugging on mics while listening for rustling. I found that the broadcast loop wasn't really helpful and may even make things worse because on clips that don't have a groove to hold that loop, the tugging just causes more vibrations as the wire slides across the clip. The rubber boot where the cable enters the mic capsule seems better at absorbing wire tug noise.

I've never heard a heartbeat. In fact I can't remember ever hearing anyone's heartbeat even without a microphone unless my ear was on their skin, certainly not when they are talking in a normal voice. I would suspect gain issues.

Steve House November 10th, 2011 06:48 PM

Re: Hiding Lav Mic
 
Quote:

Originally Posted by Tom Morrow (Post 1695959)
I actually did some experimenting a month or so ago, tugging on mics while listening for rustling. I found that the broadcast loop wasn't really helpful and may even make things worse because on clips that don't have a groove to hold that loop, the tugging just causes more vibrations as the wire slides across the clip. The rubber boot where the cable enters the mic capsule seems better at absorbing wire tug noise.
....

If the loop was rubbing where it passe through the hinge end of the clip you didn't have the cable clamped at the mic capsule end of the clip. The mic is on the front of the shirt, pointed up. The loop goes down, looping over and up through the clip by the hinge, then loops over again this time under the shirt, and is clamped to the shirt by the alligator clip. Since the wire is clamped, a tug can't cause the loop to contract.

Tom Morrow November 13th, 2011 12:19 AM

Re: Hiding Lav Mic
 
My experience is that if it's secured then yes that eliminates the sliding noise (although doesn't eliminate tugging noise). What's the point of having that loop if it's in the middle of two secured locations (wire goes out of microphone, loops through the hinged end of the clip, and then the wire is secured at the other end of the clip). It seems to me the loop is more of an aesthetic consideration then, since the secured location absorbs any tugs before they get to the loop.

Steve House November 13th, 2011 09:10 AM

Re: Hiding Lav Mic
 
Quote:

Originally Posted by Tom Morrow (Post 1696672)
My experience is that if it's secured then yes that eliminates the sliding noise (although doesn't eliminate tugging noise). What's the point of having that loop if it's in the middle of two secured locations (wire goes out of microphone, loops through the hinged end of the clip, and then the wire is secured at the other end of the clip). It seems to me the loop is more of an aesthetic consideration then, since the secured location absorbs any tugs before they get to the loop.

If the loop isn't there, the tug gets transmitted directly to the mic capsule instead of the shirt and clip

Tom Morrow November 13th, 2011 11:28 AM

Re: Hiding Lav Mic
 
But if the cable is clipped to the clip, then that clipped connection will transmit a tug through the clip itself, bypassing the loop.

Bill Davis November 13th, 2011 12:11 PM

Re: Hiding Lav Mic
 
Look, this argument is silly.

Those of us who have been doing this a long time do what we do because at some point we discovered that something wasn't working the way we wanted it to. So we changed stuff until it met our expectations and needs.

It doesn't matter AT ALL if you use a loop, a square knot, or personally superglue the cables to the talent's tie. The point is whether or not you solve YOUR problem in a fashion that works to YOUR satisfaction.

If you don't want to learn how other folks do it after their experimentation, fine. Or do it another way. Nobody really cares.

If you think you have an even 'better' way - great. Post it for people to try for themselves.

But to tell people that what they've been doing successfully for decades is somehow "wrong" is kinda insulting. It implies that they've been too dense for their entire careers to understand that they've never solved the real world problem they started doing the thing to solve in the first place.

The other approach is to consider that if something a lot of people are doing that satisfies the problem for them - and you're not getting the same results, it MIGHT just imply that you're implementing the practice improperly.

Or it might be that your equipment is different. Or that you haven't yet encountered the same problems that they have. Or haven't pushed the gain the same way they did - or a THOUSAND other variables.

The only real problem is the feeling that you have to somehow "educate" people that they're wrong to be satisfied with their knowledge. Respectfully, that's ego talking, not the genuine desire to help them learn.

Something to be careful about, IMO.

FWIW.

Steve House November 14th, 2011 03:18 AM

Re: Hiding Lav Mic
 
Quote:

Originally Posted by Tom Morrow (Post 1696778)
But if the cable is clipped to the clip, then that clipped connection will transmit a tug through the clip itself, bypassing the loop.

Yes, true. But a tug on the clip produces far less noise than a tug on the mic capsule itself.

Marcus Martell November 14th, 2011 04:27 PM

Re: Hiding Lav Mic
 
Picture guys!

highly appreciated


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