# Wireless Microphone Problems, with a show approaching.



## TheAngryFedora (Jan 22, 2006)

I'm working on a show that goes up in three weeks. It's my second musical, though I've designed/run other shows, and I'm having difficulty mixing the wireless mic's well. It just sounds really hollow, and it's peaking very easily with the trim pretty far down and the fader at about half volume. I'm thinking that the squelch will need adjusting, but, what might be some possible solutions?

For example, one actress has an amazing, but really high, voice. In one song, she belts out this incredible note, unbelieveable, but the mic just freaks out on me. I know that I've got to cut it back quite a bit, but even when it's practically off, it's going a little crazy. Also, she's singing it right next to the actress who plays her sister (Wonderful Town) and HER mic is up, and picks it up, especially the last note where the first sister is singing right next to her chest.

I'm sure that a lot of this is a mixing issue, I just don't know exactly what sounds good, or how to get things to sound good, especially with our sound system. It sounds so unnatural. I'm thinking of bringing in some sort of compressor, or reverb, or something. I really don't know. Would that help the sound? Would it do anything?

I've set it up so that the two main characters keep their mics for the whole show, and the other three mics are switched minimally, and always to people with a similar voice so that I don't have to do much of anything to the eq (if anything at all.)

And, would adjusting the squelch help the peaking?

Also, a problem that I'm having is that when I try to get some decent volume, the sound distorts. A bit higher and it feeds back, even though it isn't all that loud. I'm very confused. I've been learning a lot, especially from this community, but I'm still a newbie.

Help me, O omniscient Techie community!

Is it the speakers? The mic's? The amps? The signal that's causing it to distort (though the RF meter shows full signal.)

Finally, what exactly IS squelch, and how might it be used to my advantage? 

Thanks,
Ben


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## Radman (Jan 22, 2006)

Well, the first thing I'd look at is the placement of the mic element. It's been a while since I've placed lavs, I forget the tricks of the trade, but I'm sure others here will be able to help guide you in the right direction.


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## TheAngryFedora (Jan 22, 2006)

Right now they're placed on the lapel. I'm hoping to move them to either taped right in front of the ear or on the forehead (ear is preferable.) I just can't find goot tape that will stick well and blend well. The actors are going to sweat, so I need something that will STICK. I posted this on a forum strictly dedicated to recording/sound (the exact same post.... I'm greatly in need of advice) and got some great feedback. I'm hoping for the same here, but, some of what was said was that I might want to get ahold of a couple of 32 band EQ units and bus the male vocals and female vocals into one each to help the general sound. Also, just to make sure that the output level/squelch on the reciever/transmitter are adjusted properly. I was also told that a compressor would not be a bad idea. Realistically, though, we don't have much of a budget for any of this. MAYBE to rent the EQ's. But I don't know. I'd have to check.


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## mbenonis (Jan 22, 2006)

The first thing you should do before anything else is to try putting the mics over the ear or on the forehead. See how this works in rehearsal - you might not need to do much more.

To mount the mics, you can try a number of different methods. On girls, it's easiest to bobbypin the element into their hair. I'm partial to the center of the forehead, but over the ears works as well. For guys, it can be more difficult due to hair length. One common method of mounting is to use florist's wire to create a miniature bracket that fits the ear and attaching the element to that.

Next, you note that at some points the actors are standing face-to-face with both mics on. When this occurs, kill one of the mics - period. You're going to have more trouble with comb filtering* than you will with the actors not being heard.

If these don't work, use a graphic EQ to notch out the frequencies at which the mics feed back the most. I would suggest doing this over just the wirelesses, but if necessary it can be done over the entire mix as well.

If you're still having howling problems after trying all of the above, you may simply be trying to mix them too loud. Try lowering their volume and asking the actors to speak up more.

You shouldn't need to fiddle with the squelch - it determines the point at which a receiver will declare a signal too weak and cut the mic off to avoid radio noise. It won't do you any good to adjust it unless your mics are dropping out.

*Comb filtering is a nasty sounding phenomenon that occurs when the same voice is picked up by two microphones at different distances.


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## TheAngryFedora (Jan 22, 2006)

Thank you very much. I'll try that out tomorrow, see what happens.


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## AVGuyAndy (Jan 22, 2006)

Don't touch the squelch, it has nothing to do with this problem. Squelch is for overcoming noise. (static) A compressor will help knock down the peaks. Try messing with the board EQ first.


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## Foxinabox10 (Jan 22, 2006)

For mounting...clean the area of the face with rubbing alcohol (cleans the surface for the tape) and use medical tape...just standard semi-clear tape. It also allows you to make-up over it.


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## jbeutt (Jan 22, 2006)

What equipment are you using?
When you say it's freaking out on you, do you mean it's clipping? Sounds to me like you have improper gain structure.


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## jbeutt (Jan 22, 2006)

so i read your post on recording.org which answered my question. ew100 transmitters have a gain option in the menu. For lapel placed mics, a good place to start is -20db on the transmitter and 12 o'clock on the receiver gain knob. 

Also, you'll be hard pressed to find a 32 band eq. But the eq is sort of extraneous right now. Your problem definitely sounds like gain structure. Your tinny sound is probably comb filtering, as was mentioned. The eq on mackie is alright, as long as it has a sweepable mid, but if you can get your hands on a couple of parametrics for the leads, that'd be pretty handy.


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## RockLobsterNet (Jan 23, 2006)

What specifically are the mic peices that you are using? Are they the tiny kind like the Countryman B6 or the normal, larger kind? Your problem sound like it is mostly just placement and maybe some EQ. The board EQ should be enough--31 band EQs would be overkill.


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## Mayhem (Jan 23, 2006)

If you have trouble with the tape sticking to the actor's skin, you can use a "barrier wipe". Now I am not sure what name they go by in the US (or other countries for that matter) but a drug store should sell them. 

They look like the little alcohol wipes that are used in hospitals and medical centres but actually make the skin sticky and also protect the skin as well. 

They are mainly produced for use on patients that have colostomy or illiostomy bags to help stick the bag to the skin and also protect the skin form damage.


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## jbeutt (Jan 23, 2006)

if you're having major sweat problems, I hear a bit of mole skin attatched just above the mic element is good because it'll catch and absorb the sweat before it gets down to the mic. Never tried it myself though.


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## TheAngryFedora (Jan 23, 2006)

Also, to protect the transmitter, we're getting unlubricated condoms. They work beautifully.

The problem with the taping of the mics to the faces, on a few of the actors, is that we have two rotating mics. The leads (two girls) and one of the male leads are definitely going to get the tape over the ear type thing treatment/whatever the hell you want to call it. I've been awake for far too long, sorry. History work. Blah. The others, though, will likely be more difficult to deal with. We might be able to rent two new elements and just swap out the transmitter for the mic changes, but, I think that is completely out of the question in terms of practicality and budget. 

Is there any way to QUICKLY (a matter of a page or two of musical dialogue) to swap out a mic and tape it around the ear? Or, do you think that I should have the rotating mic's clipped to the lapel? Those are all guys, so, flapping costumes will not be a real problem. However, placement is an issue.

Rental gear is not an option, aside from another mic if neither of our Shure lav's work. And I doubt that they will. They have really crappy reception in our auditorium.

The elements themselves are Sennheiser. Really quite small. The capsule is about a 1.5 centimeters, or close to 3/4" long, and about as thick as a pencil eraser.

What's wrong with the gain structure? I don't know all that much about it.

And, what's a good level to set the squelch at normally? Because, we do have a bit of a problem with static, and with the sound just being generally distorted, so maybe I'm just confusing the distortion with static and all we have is a gain problem as Jbeutt suggested.

Comb filtering could very well be an issue. Also, the orchestra is going to be upstage of the actors, which will probably be picked up by the mics... which could potentially be very annoying...

So, summary: Squelch- good level to leave it at, and then leave it alone? Gain structure- what do you mean? Most important, mic placement and the convenience of switching mic's that are taped versus those that are pinned.

Thanks!


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## mbenonis (Jan 24, 2006)

As far as the rotating mics go, I think you're going to have to go with lapel unless the wearer has enough hair that the mic can be hidden quickly and easily.

Let's go into some gain structure now.

Your goal in setting gain structure is to keep a consistent level through all of your equipment, with as little amplification as possible. It's not that hard to do, but it can take a bit of time.

The first step is to set the input level on the transmitter itself. On some units this is a continuously adjustable pot; on others, it's a switch with only two or three positions. In either case, you'll want to ask the primary user of the microphone to speak or sing at the loudest level that they will during the show. They shouldn't be shouting, but projecting. Now, with the receiver in plain sight, adjust the control so that the indicator on the receiver shows the audio at around 0 dB. The transmitter is now set properly.

The next step is a matter of personal preference. On most receivers, you have the option of setting the output level to line or mic level. Personally, I prefer to set it to line level so that any noise injected into the cable is negligible. Make your choice and head back to the board. Turn the gain all the way down, and ask the person to start talking/singing again. Hit the PFL/Solo button for that channel, and slowly increase the gain until the bargraph meter indicates that the audio level is around 0 dB. During the next rehearsal, it may be necessary to adjust the gain to get an optimal audio level with the fader set around 0 dB.

By the way, if there is a level control on the receiver, set it to either 0 dB or all the way up, depending on how it's labeled. Usually such a control is designed to turn the level down, not amplify it, and it's counterproductive to turn the level down at the receiver and back up again at the board. Remember, the whole idea here is to avoid extremes - the gain cranked up, the fader all the way down, etc.

If this doesn't work, the next thing I would look at is frequency intermodulation. Intermod, as it's often called, occurs when two frequencies combine to make a third frequency close to one being used. For instance, if I had two mics running at 500 MHz and 501 MHz, two possible intermodulation products would be at 502 MHz, and another at 499 MHz. If you had another mic at either of these frequencies, you might have a problem on your hands. I have a checker program that I can run your frequencies through to see if any of them conflict. It's not particularly easy to use - it's written in C and requires hard coded frequencies - and that's why I'm not really offering to send it to you. If you want it, you can have it, though.

There is another possible, but less likely problem, involving local TV stations. If any of your mics are set to the save frequency that local TV stations use, you can also get interference. However, that's not a huge problem unless you live near a tower.


If you're still having problems, you should try to place the receivers closer to the stage or backstage - this often clears up any problems, even if it's not a permanent fix.

By the way, can you tell us exactly what equipment you have? I saw above that you have Sennheiser EW100's, and you mention some Shure's. It would be very helpful to know what models the Shure's are. By the way, do you use handheld radios or other wireless gadgets or gizmos around the theatre? They might also be causing problems with intermod and pure signal strength.

If none of these suggestions have helped, then it might be time to play with the squelch. You should set it to the point where you just barely don't hear any static. You'll have to experiment with it - it's not something to be done in one minute. Squelch is usually best left to the manufacturer, because it's easy to set it to a level that sounds really bad.

Let me know if you have any more questions - I would be happy to elaborate more on the above.

Mike

PS - I think I'm turning into ship, only with better grammar.


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## jbeutt (Jan 24, 2006)

If you're going to be dealing with mic changes, throw out the taping idea. Your best bet is going to be to build headsets. You can do this using standard wire and rubber tubing. 
It's dificult to give specific instructions, your best bet will be to experiment, but the basic idea is this: The wire acts as a support and boom for the microphone. So your wire should grab one ear (let's say the actor's right) wrap around the back of the neck and grab the other ear. Then you'll want to attatch another bit of wire from the left ear that extends out a bit onto the actor's cheeck. your final step of course is to mount the microphone, which is pretty simple. Just attatch the element to the end of that boom then run the cable along your wire to the back of the neck where it should then drop down under the actor's shirt to the transmitter. 
All your connetions (wire to wire and microphone to wire) should be done with the rubber tubing. You may want to try different types (stretch tubing or shrink tubing). 
Now your mics are mounted fairly securely in the proper place on the actor and they're pretty easy to change out. 
I really hope i made that clear and if I didn't I at least hope I sparked some idea.


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## Foxinabox10 (Jan 24, 2006)

I disagree with the people above that said forget the taping if you're switching microphones. It's not that hard to do and it works a lot better because it is so much more secure than a home-built headset. I always have someone on a headset on each side backstage in case we need to switch mic batteries or something and they tape people up after mic changes occur. It's not that bad to do if you get a little experience taping them.


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## BillESC (Jan 24, 2006)

Here is an excellent tutorial on the use of multiple wireless mics.

http://www.audio-technica.com/cms/site/9d36916b31f998ae/index.html


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## avkid (Jan 24, 2006)

Make sure to even out all the gains on the body packs before you do anything.


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## jbeutt (Jan 24, 2006)

taping or pinning the mic is definitely ideal. Sometimes it's hard, especially at a school, to get reliable people who'll do something consistantly and correctly. If you have those people, go for it, but the homebrew headset is something an actor can easily deal with themselves. Plus it's a little faster than taping if your changes need to be rrrrreally quick.


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## mbenonis (Jan 24, 2006)

avkid said:


> Make sure to even out all the gains on the body packs before you do anything.



This is good advice if all of the people project and sign at the same level. If not, however, this can lead to either really low signals or really hot and distorted signals. That's why I suggested leveling the mics while the actors are actually reading lines earlier. You'll make up for any differences with the board's gain control.


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## Austinro (Feb 5, 2006)

To attach microphones to actors heads that are using the mikes during the entire show, use spirit gum. This is only a good idea to do if the microphone element is large, otherwise bobby pins work. If you are switching mikes during the show, it is best from my experience to just clip them or re bobby pin them. Depending on how well your sound system is set up, most feedback in any one space with similar microphones will be on the same frequencies. On a mackie with a sweepable EQ, you will want to cut out almost everything between the ten o'clock and one o'clock position (I can't remember the frequencies). I happen to use a SR32-4. Anyway, you will want at least a 24 band EQ (unless you already have one) between the main board and the amps. Give yourself some feedback that you normally get, and then try cutting out frequencies on the EQ untill the feedback goes away. Do this as many times as you need. 
If you could take pictures of all your gear and post them, it would allow us better to tell you what you will need to do. If your wireless packs have a screen with a level indicator on them, make sure that that level is not peaking with normal use. If if is, it is a problem with your pack.


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## TheAngryFedora (Feb 13, 2006)

Thanks so much to everybody who helped out here. The show went off spectacularly. I found a two-channel, ten band EQ with broken VU meters that worked very well. The sound wasn't spectacular, but hey, I'm a perfectionist, and it was certainly a major improvement from last year's sound.

Spirit gum- bad idea. I tried that during tech week. I was very careful, but it fell off partway through the show and the actor didn't tell me, he just stuck some more spirit gum on there and stuck the mic down. Now we have one less lav. Goodbye $400 microphone. From top to bottom: cheek bone, spirit gum, molding putty (the stuff used for blocking out facial hair, for creating different facial shapes, etc,) mic, more putty. The mic fell off somehow, and he just put some spirit gum on the putty and put it back. Don't know what happened, but it was nasty, and I now have a fear of spirit gum. So, it probably works fine, but I'd be careful..

Thanks again, and I'm saving this forum for future reference. There's always really great stuff that people throw in here.


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## mbenonis (Feb 13, 2006)

What kind of capsules are you using? $400 seems a bit pricey for capsules used with high school productions - I used $60 WL93's and they sounded fine!


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## TassieBogan (Feb 21, 2006)

OOH!!! Don't i just know the feeling!!!!

we have a production of Back to the 80's going up in 1 1\2 weeks and the Theatre Manager dropped the Multicouplers for our VEGA U2020 radio mics. not we have to way to power the recievers.

ah well, it'll resolve it's self at the last minute.

After all, if it wasn't for the last minute, nothing would get done.


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