Microphones and face shields

Sarabande11

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I’m also currently involved in prepping for a summer teen production with body mics and masks (and hopefully a lot of social distancing on stage and in the audience). We’ve done some trials so far, and much of it has to do with where you plan on mounting the element. No matter what, you will be dealing with some amount of noise from the mask, rustling as well as the likelihood of the element and the mask connecting and making noises unpredictably.

On top of that, obviously, the mask is going to restrict/muffle the sound the actor produces. Having the mic near the ear or further back on the cheek with less available headroom opens you up to more likelihood of feedback, among other things. Using a boom or getting the mic on top of the mask somehow, and therefore moving it closer to the person’s mouth, is what we’ve been toying with. We’re actually having the kids use mic clips to secure it to the edge of their masks on the exterior so the element is actually right near the edge of their mouths inside the mask. Putting it inside the mask exposes the element to too much possible contact noise between face and mask.

We’re also making them exclusively handle their mics themselves as much as possible, to limit our mic technician’s exposure as much as possible - luckily the way we are doing this production is allowing for this.

I hope some of this gives you some good ideas. Keep safe and good luck!
 

jkowtko

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Redwood City, CA
Sounds like forehead mounting is out ... I imagine that would sound literally like they have a helmet on. Since B3s are omni, my first inclination is to get them as close to the mouth as possible for best GBF, use the shield to your advantage if possible for mounting the mic in front of the mouth, keep the mic element as far away from the reflective surface of the shield as possible, maybe add a bit of sound damping (cloth) between the mic element and the shield.

Unless someone has done this before and knows what sounds best, I suggest spending a bit of time having the actor hold the mic head in various places under the shield and sound check until you find the *right* spot for your equipment. You might have to do this for each actor as well.

On the mic channel EQ I imagine you're going to have to attenuate the low end quite a bit.

Good luck, and let us know what you find!
 
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macsound

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Depending on your ultimate placement, you're kind of putting the mic into a tunnel between the body and the mask. So your EQ will need to include actor plus face shield resonance/ reflection in whatever position you put it.

Also thinking about the curvature of the face shield kind of like a football sideline parabolic reflector, you'll probably gain some gain. Careful with that.

Hopefully the resonant frequency of the lav facing into the face shield is consistent from actor to actor, something like the frequency you EQ out for people who like to cup a 58.
So you could send all the Lavs to one group to do EQ instead of dealing with it on every single input.

And yes, please do share what works. I'm sure we will all end up doing this at some point.
Also if you figure out how to not get the lighting to cast a glare off the face shields, feel free to share that too. I'm sure also something we will all have to deal with. :D
 

What Rigger?

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I am reluctantly running audio for a school musical in early August. Actors will have B3 microphones, and the director is requiring them to wear face shields. What kind of issues will I have with the microphones and face shields, besides the obvious? 😕
I'm gonna go ahead and say the obvious: stay super on top of what the school/district is really going to do. It seems like everyday more districts are putting the kibosh on everything in-person. In light of what could be a human cost, the frustration of doing a whole lot of work for nothing pales in comparison...but save whatever brain cells you can by keeping an eye on the administration.
 

FMEng

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I hate to rain on the parade, but face shields have been proven ineffective by themselves because they do noting to suppress the aerosol cloud. Masks are more effective, but doing a play now is stupid, even if some "authority" allows it. If it were me, I wouldn't participate.
 

TimMc

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Arrrgg. These are the kind of things that give me heartburn. Not so much the audio side but the director thinking he/she/they is an infection control expert.

I'll deal with audio... The semi-enclosed space between the shield and face will have it's own resonant frequency that will exacerbate some frequencies and attenuate others (comb filtering). As for mic placement - none will negate the resonance but some may be more forgiving than others. One thing I might be inclined to try is to mount the mic element to the inside of the shield, off center, and use the combination as a kind of "PZM". It's still gonna sound weird.

Coronavirus - I think the director is ill-advised to attempt a musical right now, especially if he/she/they consider a face shield to be an effective means of infection control. Shields, masks, hygienic practices, distancing, etc are all part of a "system" of transmission control. Individually they are not fully effective but when combined, present a more efficacious package. If I were the principal or headmaster of this school, I'd want some review from a Local Authority assessing the risk to actors, crew, and audience.... students, teachers, parents and adult volunteers... presented by various interactions, distances and exposure times. And how are multi-touch items like mics & transmitter packs going to be hygienically swapped? How will they be cleaned before and after each use, and how will that be tracked? Who will do it and what legal liability do they incur?
 

JD

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North Wales PA
As Tim pointed out, mount the mic to the inside of the face shield. You will have a resonance problem no matter what, but you should be able to minimize that with EQ.

Also pointed out was that masks are ineffective and that school districts (as well as anybody trying to put any event together) can turn on a dime and cancel the whole thing, so I would not invest time outside of planing out what you would do.

I am looking at an outdoor choir rehearsal this next week and mic'ing the director. I believe this will be a mask event although I know they also have a supply of face shields they bought before the reports came out. Plan is to spread the choir members out 6 feet and with masks on a parking lot. The idea is to simply see if this low a density can function as a choir, or if the distance and masks kill the ability of anyone to actually hear anything.
 

BCAP

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Ohio
Face shields? Plastic face shields?

This is just my opinion. I could be wrong so feel free to disagree...

I personally think you are gonna get comb filtering effects with an omnidirectional lav mic like the B3 placed inside a face shield. The end result might sound thin, phas-ey, or unusual. There might be lack of low end. It could also sound "boxy" or "tinny" depending on the filtration effect. I doubt this will be avoidable if you cannot move away from face shields.

If you've ever tried to mic someone wearing a motorcycle helmet when the microphone cannot be right next to the lips... same thing. The microphone will pick up a variety of different reflections off different surfaces inside that cavity between the face and helmet and the signal at the microphone represents the sum of different direct and reflected paths of the signal back to the microphone - some versions of the signal with various very tiny delays. This will result in frequency cancelations (and resonances) when all the acoustic signals are combined at the microphone diaphragm. Whether they are severe enough to count for you or not - and what the specific character of impact on the sound is hard to tell. I think it would depend on experimentation.

You might be able to combat resonance issues with EQ, but I'm not so sure it would be easy to identify the cancelations or do anything about those.

I wish you best of luck.
 
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BCAP

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And how are multi-touch items like mics & transmitter packs going to be hygienically swapped? How will they be cleaned before and after each use, and how will that be tracked? Who will do it and what legal liability do they incur?
I asked the same question of some colleagues and someone suggested UV light as one way to sanitize certain items - at the least, headworn mics. I think it's a good idea but certain plastics - urethanes, foams, etc. break down in UV light.
 

BCAP

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I'm sure I'm not putting forth anything someone else hasn't already thought of here, but there are a number of different ideas I've heard tossed around about safely doing musical productions in COVID-19. Some of them are pretty interesting but most of them involve offline-recording or videotaping (or both) a certain amount of content for the show. Maybe they record the pit orchestra offline and everyone sings to the recorded track. In some cases it's been suggested the chorus could also be recorded individually (audio) one at a time onto those tracks - leaving only the leads to speak and sing their parts live, etc. Other times what was suggested was an onstage video projection screen available for the production to cut down on the number of chorus singing onstage. Seems unusual at first... but maybe those ideas are something to consider.

One positive - video and audio technology is quite advanced now and conveniently available. If all of this had happened several decades earlier it would be a different story.

Instead of a 100% live production, perhaps your school might be convinced to consider a hybrid recorded/live solution?
 

JimOC_1

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Why contribute to putting people in danger?

Fwiw. My situation is different because I’m a volunteer. I do a significant amount of the advertising for the fundraising events put on by the different organizations at my Church. I was stunned to hear talk of continuing with the normal Oktoberfest, BBQ, Christmas Bazaar, and more. So last week I sent around an email pulling my participation in all of that until we are all vaccinated (November 2021?). Essentially taking away my basketball and going home, not a popular move. People are just too valuable to put at risk.

And No, 6 ft is not adequate for people projecting voices or exercising.

getting down off the soap box now
 

TimMc

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I asked the same question of some colleagues and someone suggested UV light as one way to sanitize certain items - at the least, headworn mics. I think it's a good idea but certain plastics - urethanes, foams, etc. break down in UV light.
Yeah, and when Shure, Sennheiser, DPA, PointSource Audio and Countryman can tell me how much UV-C I can expose their products to, and how many times before durability or performance is compromised, I might try it. There are a couple of shops doing it now but without guidance from manufacturers and those shops are big enough that if a bunch of SM58s get damaged it's not the end of the world.

The main issue here, as I see it, is people not qualified to be giving advice are doing so. My personal issue with UV-C: how do you know it did its job? With quarternary ammoniums, phenyl phenols, isopropyl alcohol, hydrogen peroxide (even soap and water) - known products using testable concentrations and verified contact (wet) time will yield known results. Some products cannot be easily or safely cleaned with liquids or certain cleansers and for those, perhaps UV-C is a suitable decontaminate but before I use it I want the device or gear manufacturer to tell me I can safely do.

I'm on a panel that is proposed for the AES Convention's live audio track and our focus is 'coping with covid' and what getting back to work in live audio is likely to entail. Cleaning of multi-touch items like microphones of all types, belt pack transmitters and IEM receivers, intercom headsets, handsets and belt packs, stands, mixing consoles, down to how infection control impacts how we handle equipment, direct crew, and interface with talent. I suspect by the time the convention comes around a good bit of the materials and practices stuff will be more common knowledge. Right now the plan is for each panelist to give a 5 minutes presentation on an aspect of the pandemic and how we audio professionals might deal with the issues presented.
 
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What Rigger?

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BCAP

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The main issue here, as I see it, is people not qualified to be giving advice are doing so. My personal issue with UV-C: how do you know it did its job? With quarternary ammoniums, phenyl phenols, isopropyl alcohol, hydrogen peroxide (even soap and water) - known products using testable concentrations and verified contact (wet) time will yield known results. Some products cannot be easily or safely cleaned with liquids or certain cleansers and for those, perhaps UV-C is a suitable decontaminate but before I use it I want the device or gear manufacturer to tell me I can safely do.

I think that's wise. I plan to do the same. BTW I am not qualified to be giving advice on sanitization of equipment, my primary reason in bringing up UV light was to explain that someone had suggested it to me but I had some concern with it. Hoping nobody takes my comment as a recommendation. :). I look forward to the AES panel.
 

TimMc

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I think that's wise. I plan to do the same. BTW I am not qualified to be giving advice on sanitization of equipment, my primary reason in bringing up UV light was to explain that someone had suggested it to me but I had some concern with it. Hoping nobody takes my comment as a recommendation. :). I look forward to the AES panel.
Note that I'm not being critical of you or your post, but of the suggestions you were given by well intentioned, but uninformed people.

{personal soapbox} I suspect a great deal of cleanliness and sanitation are conflated, confused, and presumed to be difficult (biologically) and requiring esoteric, high tech solutions. Pfft. Balderdash, Bah Humbug, etc. Common, food-grade sanitizers are likely adequate when used according to directions. For example I have some Kirkland (Costco) brand sanitizing wipes. They use a double-quat ammonium (0.28% by weight) as the chemical basis and the package instructions for *cleaning* require a wet surface for at least 15 seconds. For *sanitation* the instructions call for a 3 minute, continuously wet application. Which is good enough? Ask a public health person... Is it safe for the equipment or device being cleaned/sanitized? Ask the manufacturer. Bonus give-away: *many* equipment manufacturers are liking 70% isopropyl as being least-injurious to their equipment when used as indicated in guidance.

My point is that for *most* objects used by audio people, casts, crews, and pit musicians... cleaning does not require spending money on equipment and materials of unusual natures or technologies. The chemicals needed are likely already in use in the school or theater so there is little re-training, no new MSD sheets to issue to workers or volunteers, no new storage or handling requirements...
{/personal soapbox}
 

teqniqal

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The point many 'amateur virologists' miss is that a virus is NOT a germ. A virus has a fatty lipid shell protecting it. You need SOAP to break down that shell to kill a virus, NOT hand sanitizer. Use the right tool for the job! Surgeons don't scrub for a surgery with hand sanitizer -- they scrub with soap.
 
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