View Full Version : Lapel mic sound different when head is turned


Peter Wu
June 19th, 2018, 01:51 AM
I recorded an interview with a cheap lapel mic on the talent. For convenience, I clipped it on one side of her V-neck.

As the talent talked and turned her head from one side to another (facing different interviewers), the sound quality changed slightly - more bassy when the mouth is closer to the side of the lav.

Is the solution to buy lavalier mics that does not have proxmity effect? But how can you tell because that's not always mentioned in the spec?

Or should I clip the lav at the dead center of the clothings?

Andrew Smith
June 19th, 2018, 02:24 AM
Essentially, works as advertised. You will always get a different tonality when the subject is addressing to a different location to where the mic has been placed.

From memory I believe one solution for this (and also mic pops) is to attach the mic facing downward. You will still get some differences in your levels but the tonality will be consistent.

Andrew

Darren Levine
June 19th, 2018, 07:22 AM
With lav mics there's a number of dynamics

first, is it omni or uni directional? if you have a cardiod (unlikely if it's cheap), then you're too directional for lots of head movement,

distance, being closer to the mouth is good for leveling down external noise, but bad for head movement which changes distance and source direction. moving the lav a bit farther down can help, but not too far or it will sound too distant and allow more external noise

orientation, like andrew pointed out, you can point the mic down, but i wouldn't do this with a cardiod, only an omni

position, centered is best if the will be looking fully left to right, or if they're only talking to mostly one side, try to favor that side a bit

Rick Reineke
June 19th, 2018, 09:15 AM
That's why cardioid lavs are usually not recommended. In addition, cardioid lavs are sensitive to air turbulence, (wind and/or plosives) rubbing and cable noise.

Jonathan Levin
June 19th, 2018, 10:24 AM
Probably best to plan in advance which way talent will have head turned and stay with that. Or have boom op that can follow head movement.

Paul R Johnson
June 19th, 2018, 04:28 PM
Lav mics with proximity effect are cardioids, and pretty useless, other than for special circumstances. The entire point with lava is that placement is rarely ideal, so something that needs keeping specific distances away from the mouth simply won't work. I have lots of omni, and two cardioids - and in ten years, I think I have used the cardioids once, when I needed to reduce background noise - and they worked. Just not everyday use. They're also bigger than the typical omni.

Bruce Watson
June 20th, 2018, 09:30 AM
I recorded an interview with a cheap lapel mic on the talent. For convenience, I clipped it on one side of her V-neck.

As the talent talked and turned her head from one side to another (facing different interviewers), the sound quality changed slightly - more bassy when the mouth is closer to the side of the lav.

Is the solution to buy lavalier mics that does not have proxmity effect? But how can you tell because that's not always mentioned in the spec?

Or should I clip the lav at the dead center of the clothings?

Always use omni lavs. I've never run into a reason to use a cardioid or hypercardioid. Ever.

As much as possible, you want a lav right square on the sternum. This is typically a little farther down than newbies think it should be; newbies typically try to get closer to the mouth. But closer isn't always better, and this is one of those times. Why? You want it out of the "chin shadow", and you want to minimize changes in sound quality as the talent moves about. There's a lot of accumulated experience that points to this "center of chest" location.

Given a v-neck sweater, I typically ask the talent to clip it right at the bottom of the vee. I don't do it because I don't want to invade talent's personal space. I do everything I can to make talent sound good and be comfortable doing it; that's the path to good video interviews IMHO. If the talent is uncomfortable for whatever reason, it typically shows through in the resulting video.

Note that if the lav is visible in the shot, viewers can see how talent's head moves with changes in sound quality. That the viewers can "map it" as it happens makes them much more forgiving of sound quality changes.

So... three things: Omnis. Placement. Visibility.

There's a fourth for extra credit. That is, learn to make and use a strain relief loop in the mic cable just below the mic itself (make a simple loop and tape it in place). This will help with cable noise due to talent's movements.

And a fifth, if you have that kind of influence. Restrict talent to natural fibers only, no synthetics. This will markedly help with clothing rustle. Polyesters and Nylon may look good, but they tend to be noisy.

Peter Wu
June 23rd, 2018, 02:15 PM
Asking the talent to clip the lav doesn't work very well for me. The lavs ended up looking sloppily clipped.

So last time, I ended up clipping the mics for everyone even though I had to put my hands inside their blouse/shirt slightly to tuck the cable. Nobody seemed to notice or mind. They're too focused on rehearsing their lines.

However, I don't think I can get away with putting tapes inside their clothing. How do you do that? Is pickpocket skill required?

Fortunately I don't have cable noise to deal with yet.

The lavs I use are indeed omnis.

David Peterson
June 23rd, 2018, 06:31 PM
However, I don't think I can get away with putting tapes inside their clothing. How do you do that?

It is very simple:

1) get tape
2) tear off appropriate length of tape
3) orientate sticky side of tape towards what you want to attach to
4) place tape over cable at desired potion
5) press down firmly so it sticks
6) profit

Ty Ford
June 29th, 2018, 04:18 PM
Asking the talent to clip the lav doesn't work very well for me. The lavs ended up looking sloppily clipped.

So last time, I ended up clipping the mics for everyone even though I had to put my hands inside their blouse/shirt slightly to tuck the cable. Nobody seemed to notice or mind. They're too focused on rehearsing their lines.

However, I don't think I can get away with putting tapes inside their clothing. How do you do that? Is pickpocket skill required?

Fortunately I don't have cable noise to deal with yet.

The lavs I use are indeed omnis.

You can get fall off with an omni lav. With a little planning and help from makeup/wardrobe, you'll be fine.

If the person is in the middle and plans to be head turning, I'll put the mic in their midline. If they are talking to one side, I'll put the mic there.

You can mitigate big changes by placing the lav lower, but eventually, you run into problems there.

Regards,

Ty Ford

Rick Reineke
June 29th, 2018, 06:06 PM
In theater, it's common to mount the mic on the talents head. That pretty much eliminates head turn issues but creates others. Nothing's 100% perfect.

David Peterson
July 1st, 2018, 04:01 AM
You can get fall off with an omni lav. With a little planning and help from makeup/wardrobe, you'll be fine.

If the person is in the middle and plans to be head turning, I'll put the mic in their midline. If they are talking to one side, I'll put the mic there.

You can mitigate big changes by placing the lav lower, but eventually, you run into problems there.


Tony Johnson would place *two* lavs on an actor to get around this issue:

https://zaxcom.com/the-hobbit-a-production-sound-perspective/

Each film created its own set of challenges, but Johnson and his two boom operators, Corrin Ellingford and Steven Harris, consistently took the time to wire all the actors each day. The team used Zaxcom TRX900 transmitters in combination with Countryman B6s, DPA 4063s, and the occasional Sanken COS-11D for lavs depending on the application or actor. For the hobbit Bilbo (Martin Freeman), two lavs were needed at times. “Bilbo had this jacket he wore with lapels on it. What we did was put two wireless lavs, one on each side of his lapels, being Countrymen B6’s. They were placed at identical heights and levels so no matter which way he would swivel his head, the audio would match,” explains Johnson. “It was the first time I used two mics on an actor and it worked very well.”

David Peterson
July 1st, 2018, 04:06 AM
For the fourteen different dwarves, they used little hair clips to hide B6s into their beards. And in the case of Gandalf (Ian McKellen), sound hid a TRX900 with a B6 into the cone of his hat. “That saved so much production sound because it was like having a boom a few inches away from his mouth,” notes Johnson.

I'm very curious as to why he didn't use the same approach with Gandalf and put the B6 in his beard like he did with the dwarves? (also why a B6 if it will be hidden in the hat? As I understand using a B6 for its very small size if hidden in a beard but if the mic is kept under a hat then why not use a bigger/better lav? I suppose for the consistency of using the same mics in the entire scene)

As I shot a few years ago a web series pilot that was a parody spoof of LotR and our "Gandalf" character (who had a looooong beard, but his actual beard was shorter than mine! ha) I found sounded absolutely fantastic when I place a lav under his beard.

I think I should offer to shout Tony a beer or two to pick his brain over this and other questions! As I'd love to know why, I guess it sounds better there in his hat? But my initial first gut guess is that in the beard would sound better?!

Seth Bloombaum
July 1st, 2018, 09:23 AM
I'm very curious as to why he didn't use the same approach with Gandalf and put the B6 in his beard like he did with the dwarves? ...
I’d guess this description is incomplete.

A lav under the brim of a hat can be an excellent placement. I’d also guess that hat-vs-beard-rigging meant that they never had to hide cable for G. It was all built into the hat!

David Peterson
July 1st, 2018, 05:33 PM
Ah yes, of course, that makes waaay more sense!
It was just the description that was incorrect, they meant the brim of the hat as that is indeed a great place. And being in the brim then using a small B6 makes sense.