Need recommendations on lavalier mic use

smhontz wrote on 1/24/2005, 3:18 PM
Based on recommendations on this forum, I purchased the Audio Technica U100 series wireless microphone system from B & H. It came with the AT831cT5 cardioid mic and I also picked up the AT899cT5 omnidirectional mic. I could use some advice on picking the proper mic and accessories for the type of shooting I do. I am shooting public speakers; sometimes they are on a stage, roaming freely back and forth, and sometimes they are in a classroom, where they may be near a laptop/video projector with the associated fan noise.

Questions:
1. Is there any reason I would favor using the 831 cardioid mic vs the 899 omni? Would I be less likely to pick up fan noise if I use the cardioid, or is the 899 a better mic to use regardless? If I use the cardioid mic, will the levels drop when the speaker turns their head?

2. Both mics come with the foam windscreens; should I always use them, or only if I'm outdoors?

3. The 899 also came with 2 "element covers". Are those just protective devices that I should always have on, or is there a specific acoustic purpose for them?

4. I notice in watching some news shows that it looks like when someone is wearing a t-shirt type collar, they kind of loop the mic at the collar so it points somewhat down at a 45-degree angle. Is that a mistake or does that have a purpose?

5. The 899 also comes with the "viper" base (stick pin holder) and a magnetic base. Are there circumstances where these bases are better to use than just the "alligator clip" type bases that you normally see used?

Comments

farss wrote on 1/24/2005, 4:30 PM
I can't answer all of these questions however yes there is a trend to pointing lav mics down, I think the reasoning is to reduce the proximity effect.

As to what difference using a omni Vs a cardiod will make, I suspect if the wearer turns his head they'll perform much the same, with either of them you will get not only a shift in level but a dropoff at the bottom end. What I'd be using the omni for is at say wedding where you only mic the groom but want to pickup the bride and celebrant.
As to protective covers, the big problem with lavs is clothing noise, anyone wearing low neck clothing can have another problem. Make certain the clip isn't touching their skin, the sound of someone scratching at the mic is not nice, been there, had that happen to me.

With all these things, TEST it yourself.
Can I just add one thing, we're exclusively Sennheiser so I don't know how this translates into what you're using. Most UHF mics are FM and use a compander system. You have to get the right level into the transmitter, this is critical, I mean critical BIG time! If you overload the front end in the transmitter your audio is USELESS, I don't know exactly what goes on there but after hours with Clipped Peak Restoration I've not been able to pull back audio thats suffered this fate. I suspect the problem was compounded by the guy realising the levels were too hot and turning down the reciever, all that gave me to work with was low level distorted audio!
So if your transmitter has an input attentuation setting you need to get this just right, too much attenuation and you'll get less tha ideal S/N, too little and you'll distort, the former is preferable to the latter.
In the instance I'm talking about it did take a pretty full on SPL to get into this situation, the guy was standing in front of the PA speakers at one point and not at others!
Bob.
FuTz wrote on 1/24/2005, 5:11 PM
1-don't know much about the cardioid mic, lavallier type... Most of the kits I’ve worked with here usually have omni mics mounted and I guess it's for one reason: the point you mention about subjects turning their heads. I don't know how much directional these mics are (cardioid) but if it's too much, you amplify the problem (proximity effect). The best way to know is plug and compare on yourself, turning your head. Don't fix the mic too much under the chin; 3"- 6" down on the chest and you reduce this proximity effect. It's a question a evaluating and re-placing if needed. Beware of chains with medals some wear under their shirt : click-a-tick / zzrrr-zzrrrh sounds when they start gesticulating. If not simply banging on the mic at occasions during their speach... ouch.
2-If I were you, I'd particularly put them since these people are probably gonna watch their laptops, which means if they talk while their heads are down to look at their screen or keyboard, you risk getting these pop/flufff sounds when they pronounce their "p"/"f"/"b"/etc. They have to breathe too and most of the times, when you ommit putting these foams, it's like all of a sudden the only way they can breathe is in the mic. Musphy's law stuff...
3-I watched their site and I take for granted it's these caps that seem to go on the capsule itself? I'd put those. Probably good for very mild wind and humidity or even a drop of liquid. These probably don't affect the sound. My question, in fact, is: how come they don't put those on the mics from the start? Maybe to let people choose colors combinations? Really, I'm guessing here. And I'm even not sure it's these small caps with the membrane on the top (?)
4-It's "linked" to question 1and 2 : these are omni mics so most of the audio guys don't mind about putting these upside down since there’s no big difference in sound. But there is kind of a “hot spot” on the mic, still: the capsule (where the small holes are).
If they are fixed this this way, it might also be to avoid these pop sounds by getting the capsule itself out of the way from the direction of the source/compressed air (mouth). The wire too (if you have a “rumble-like” problem); you want it to hang softly, make a loop at some place on the way down (+-8") and tape wire over and under this loop to create an "articulation” on your line. Some wires, if you snap them with a finger, you get a "tack" sound. So try to "isolate" the line (wire). Usually, let it hang in a loose way with no tension on it. This last point is not so much critical (the “loop trick”) but if you have people that move a lot, it might be usefull to know.
There IS, actually, some clips that allow to choose the angle at which you want to have the mic. Maybe in your kit?
5-It's really just to give you different ways to fix it all. The magnetic base, for example, I would never use it with a baskeball player: the two parts could separate under shock and I'd be cooked. On the other way, I might find it's usefull for a robe with turtle neck or something like that. I'm trying to figure out but can't find a good example for the magnet right now. In fact, I think I used it once or twice in my life.
But, really, there's no rigid rule because each situation is different.
FuTz wrote on 1/24/2005, 5:17 PM
Holy, It was a long way. Farss had time to give advice while I typed this stuff.
Yes, he's very right also about rubbing the mics.
Different fabrics, different issues. No leather jacket if possible (but is that a concern now?).
And "brief" your subjects: thell them they must have in mind there is a "hot, invisible bubble" that they C.a.n. N.o.t. touch around their mic. A "bubble", yes. Funny, but that helps, sometimes, to give people such an "illustrated" advice.
Well, sometimes.
But not always.
ibliss wrote on 1/24/2005, 5:26 PM
The two post above cover it all really well.

I'd add that sometimes the caps have an influence on the sound - I know sennheiser supply slightly different caps with their MKE2 mics, which I think change the HF response slightly - but I might be wrong!

One thing to add - try and minimise the time that the radio mics are out of your hands. Particularly after being used, they often get taken of in a hurry and left lying around with no thought to the well being of the pack or mic head. I once found that an actor had left the mic head dangling in a cup of coffee (thankfully empty enough that it wasn't submerged).

Those little foam covers, mic clips and caps all have a habit of dissapearing when the wearer isn't careful removing them - they just ping of onto the floor etc.

If you or someone working with you can be there to supervise removal (and of course fitting too) it makes life much easier. Getting the mics back before the talent has gotten into a deep discussion with the public/family is generally a good thing.



farss wrote on 1/24/2005, 5:52 PM
Very good point, the 'broadcast' mics we bought as part of the new kits were very expensive and very tiny. Small <> cheap!
If you have to deal with females try to have a female PA on hand to help with the fitting/removal. I know that sounds so bleeding obvious but I've had so many things go pear shaped cause I'd taken great care of all the complicated stuff and forgot the basics like bringing my glasses!
Bob.
Spot|DSE wrote on 1/24/2005, 6:25 PM
Keep a piece of genuine black silk around, this makes a significant difference. Wrap it around the windscreen, use a BLAX rubber band to secure it. It won't make any noise if it's real silk.
If the mic is to be attached to clothing in an indoor setting, most times you are better off having no windscreen.
FuTz wrote on 1/24/2005, 8:11 PM
"Getting the mics back before the talent has gotten into a deep discussion with the public/family is generally a good thing"

Good advice!
Learned the hard way.
One day one guy disapeared so fast from the set I didn't have time to realize he was... gone.
Rigged the kit, turned on receivers and took the elevator down so I can get out on the street as fast as I can . I knew they were going for lunch but downtown, I tell you, finding a restaurant is NOT a problem. You get the picture.
So I'm there on the street with this "strange huge walkman" panning like crazy left and right so I can get a signal.
And I GET ONE ! The guys are talking:

"So , how about italian?"
-"Yeah, that'd be great. You know this place over there?"

(WHICH place NOW ? Looking left-right-left-right....)

"What place, this one?"

(Whaaaaat one ???)

-"The place with the big tomato"

(a BIG TOMATO, yesssss!!!)

I then spot the so-said "big tamato" which is a 3' sign in the air about one block away. Run over there, still listening in case they change their mind...
Get in the crowded restaurant, find the guys and now, as soon as they see me, they really have fun, clearly realizing what the hell I'm doing in that restaurant wearing all that equipment, phones on the head.

I got the mic back.
I got on time for lunch too.
And I got a cold one in a frozen bock when I got home by the evening.

Holy sheet...
Coursedesign wrote on 1/24/2005, 8:24 PM
...at least the guy didn't go pee while hooked up to the house system like happened at a seminar I was at...

I don't understand all these event managers who think they don't need a sound guy on the board at all times...

P.S. The basic rule is to never use cardioid lavs, just a lot of trouble.
Very few exceptions.
FuTz wrote on 1/25/2005, 3:19 AM

Good one Coursedesign!
In the late 80's/early 90's, I also heard more than one people actually go to WC, and not to pee...
I'm still asking myself what was that tac-a-tac-a-tac then that loooong "mini-hoover" sound...
And curiously, the subject would come back on set with, hum, lots of energy.
More curiously, a lot of them don't work that much anymore.
FuTz wrote on 1/25/2005, 3:25 AM

In fact, what's really funny with wireless mics is that people forget about them real quick...
That's where ethics enter the subject : what's in the phones STAYS in the phones.
I even heard a "friend" say not-so-nice things about...me one day on a set, hahaha !
Instructive.
rs170a wrote on 1/25/2005, 5:40 AM
There's an article titled Selection and Use of Lavalier Microphones that you might be interested in reading.
The site has several other articles as well dealing with a wide range of field audio issues. Well worth the time.

Mike
FuTz wrote on 1/25/2005, 1:54 PM
This place isn't bad either... pLaCE
In fact, they got a whole "tech tips" page on their site.