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Does Solar Power Make Noise?

How To Avoid Bad Acoustics

We Told You So 

Why Acoustical Doors Drive Me Crazy!

Microphones 101

Sound Proofing Home Studios or “What’s That Noise?”

In-Ear Immersive Monitoring

Auditorium Being Renovated? The Most Important Thing To Consider

Help! I Work In The Cafeteria And I’m Going Deaf!

Audience Mics in LARGE Spaces – VIDEO CONFERENCES

Mixing It All From Front of House (FOH)

Selecting a Digital Audio Mixing Console for Musical Theater Production

Auditorium Acoustic Options

Condominium Sound

Do You Hear What I Hear?

LED Conundrum Part 1 – LED Theater Lighting

RDM [Remote Device Management]  – The LED Conundrum Part 2

Video Conferencing – Stay Off The See Saw

Room Acoustics

Sound In Schools – Why It’s So Bad

Sound In Schools [part 2]You Are Part Of The Band

Speech Privacy

Stage Safety Basics For You To Put Into Action Today

Story of Audio … and Taxes

Video Conferencing – Stay Off The SeeSaw 

What’s The Difference Between a Contractor, a Consultant and a Tech?

YOU TUBE – visit our You Tube channel

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solar panel field

Does Solar Power Make Noise?

 

solar panel field

So, let’s talk about solar power. Does solar power make noise, or doesn’t it?

We had someone approach us recently by email saying “Hey, we just need somebody to do a quick noise study. Shouldn’t be any big deal. Hopefully you can knock it off in a day or so.”  My response was “For what?” I quickly learned that it was a solar farm that has 12 gazillion acres of panels going into an area which is rural and has a community noise code. Look at my previous video. This was a noise code that basically says, “make sure nobody is bothered.”

Power Supplies Always Make Noise

I didn’t know a whole lot about solar power, but I do know about electrical devices. I know that dimmers, inverters, and any kind of power supply always makes noise. The bigger the power supply, the bigger the noise. The frequencies are dependent on the voltage at which they operate – what load they’re operating at.

Most things, oddly enough, make more noise at half-load than they do at full load. So, I had to do some research before I even took the project. I went online and found that on YouTube there are some great videos when you search for “solar farm noise.” There are some good ones that were measured very close to, or video shot very close to, some of the solar farm equipment.  The video revealed some really annoying 3 kilohertz and 6 kilohertz buzzing noises that came out of all this equipment. Now, knowing what we were dealing with, it seemed that we should be able to calculate where would be a problem. The town code didn’t really define proximity to the noise.  Was the code referring to where people live or was it about the property lines because the properties people own there are farms and they are huge. Some of this equipment is operating let’s say 300 feet from a property line, but it’s 2000 feet from the nearest house.

For Sure, This Thing Was Going to Buzz

What we were starting with is that we do know is that this thing was going to buzz. We were told that there were a ton of these inverters going in and they also had fans in them so that, so when they start overheating, they would cool. But how do you figure out when this is occurring? Our next move was to contact the manufacturer and we got a number from them that is just a dBA number at a particular distance. Well, that wasn’t helpful.  We needed more data. So, we sent them an email asking for FFT narrow band data and explained that we needed to know how they took levels on the other equipment. We needed measurements on all sides of the inverters to determine which side the noise was coming from. They denied our request.

Thinking that was kind of odd, we then went to their website and found that they have a white paper explaining how they are working to reduce the noise of inverters, which says to me they know they are noisy and that is why they didn’t want to give us the data. We explained to the people we were working for that with just dba we couldn’t know what frequencies are in it. We didn’t know if we were looking at fan noise in their number. Are we looking at fan noise with inverter noise, like buzzing? Are we looking at transformer noise from all the transformers on the site at lower frequencies? We didn’t know what we were looking at.

You want us to sign a what????

We found out that the only way they would provide this is if we signed an NDA, a non-disclosure agreement. What those mean is that any data they give you, you can’t disclose to anybody else.  We couldn’t use it in our measurements, and we couldn’t use it in any of our reports and summaries. In my world, and I know that not everybody agrees with this, this means they are probably hiding something.

So, when people talk about solar power and how wonderful it is, it may be wonderful unless you live next door to it in the wrong orientation. In our final report we basically gave them lots of warnings. We explained frequency content and we gave them links to videos on YouTube where they could hear what we’re talking about. We added that we could not predict when and where it was going to be or at what level because we simply could not obtain that data.  We did have the dBA numbers, though, and even those were higher than they should be at what we considered to be locations of concern.

Now let’s imagine we are talking about a neighborhood, and somebody wants to put a bunch of solar stuff on their roof with a small residential inverter. If they don’t put that inside their house and it ends up outdoors somewhere, we’ve seen some data online of some of the residential inverters where they rate them at say 50 dBA and they’re more like 80 under certain load conditions because of the buzzing noises. Some manufacturers are very good, some are very poor, so it is kind of a buyer beware thing.

Even if you are putting one in your house, if the inverter ends up inside your house and it’s making 3 kilohertz and 6 kilohertz of noises, go watch some of the videos online where they are installing it inside a house someplace. Obviously, the noise only happens when the sun is out.  At night it is not going to be making noise, but during the daytime it can produce a significantly annoying noise if it’s loud relative to what else is going on in your house.

Again, we would say “buyer beware.”  Solar does make noise and whether it’s a problem or not depends on where the equipment is placed, how loud it is, and a large number of other factors that are environmental. Just don’t commit to it without thinking your way through. 

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Copyright AVLDesigns Inc. 2023+

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bad acoustics

How To Avoid Bad Acoustics

When it comes to acoustics, it’s quite common for us to get a phone call when something has gone wrong. It seems like 9 times out of 10 somebody has proceeded on a project, and they have taken a direction — they have “done some things” — and now the end-user is not happy. Whether it is a performing art space, or music space or an industrial application, when the complaints start coming, that’s when we get hired. To be honest, it’s really the wrong way to go about doing things. What should be happening is they should hire an acoustical consultant first, before they design the project.  But in a lot of projects the end-users are not speaking up. They never say, “Oh by the way, I’m really concerned about sound.”  Or “I’m really concerned about this or really concerned about that” so the architects and engineers don’t even think about what the changes of finishes and dimensions may do to the sound in those areas until it is either too late or almost too late.

Let’s talk about one situation that came up very recently.  We got a call from an architectural/engineering firm about an auditorium that they were “renovating” “acoustically.” I put those words in quotes separately because the meaning of each can be obscure, to say the least.  It was a conference call and, during this call, somebody asked if did they did the right things? So, I asked “what is the reason you’re doing this?”  Their answer was “well, the room needed to be updated.”

Next, I asked them “what about the people who use the room? Do they like the way it sounds now?” We had visited it and It’s a nice, kind of average auditorium.  It has absorption on the back of the room, including a cavity that goes out the room to an outer lobby in some locations to provide some added resonance out there.   The sidewalls have some absorptive panels that are on standoffs from the wall to absorb lower frequencies than they would without it.

Listen!  The actual users already liked the way the room sounds!

No one ever asked the end users, do they like the room? Well, it turns out in this case they do. The plans in the works were about to change all that. This is a drywall room with a drywall ceiling, which means low frequencies are being absorbed through the drywall. The music department of this particular school likes the space. The changes that they were about to make are so radical that we were compelled to draw their attention to the drawbacks. We said, “look, you really need to analyze this before proceeding.” We do our analyses by conducting field testing. We take the existing condition, which the end-users like, and we compare that to what the estimate in a model says it will be once the proposed changes are implemented.  I believe, for the sake of everyone concerned, this is the prudent way of going about things. The “look before you leap” method.

Before Making Radical Changes, First Test It Out.

We suggested that we test, report and evaluate just what they would have, if they applied the changes they wanted to make. The plan was to treat the whole back of the room. They were going to take the perforated section that absorbs all sorts of energy, and they were going to make that solid. Next, they were going to curve it. Plus, they were going to cover it in ceramic tile “because it is durable.”

But not everything that seems like a good idea is a good idea. The plan was to have ceramic tile up to about 12 feet off the ground. Then above 12 feet, they were going to place acoustic diffusion using a product that has a relatively non-absorptive characteristic. It is a great diffuser, but diffusers should be placed down low on the wall, where your ears are. Putting 12 feet of ceramic tile below and all this diffusion up above is at an elevation where nobody is going to get the benefit.  It will diffuse some sound and that will then bounce off the ceiling. And all of this is going to make the room far bass heavier than it is now. It’s also going to add strident high frequencies because, believe it or not, drywall still has a small absorption coefficient even up at high frequencies. So suddenly you are going to have this room with a twang to it and diffusion occurs where no one sits. And this giant curve to be added to the back of the room will create a major echo back to the stage. So, we are truly hoping they hire us to solve this problem before it occurs.

Before making decisions, ask the end-users what they hear!

One of our ways of dealing with this is to send the end-users a questionnaire with guided questions to get a sense of what they hear. It is hard when you don’t get to meet with the people and hear a live performance where you all can talk about it and say, “Hey, what are you hearing?” But we do our best. What do you think about this? What do you think about that? And then we’re hopefully going to guide them to make changes that are in line with what the end user wants acoustically the result they’re looking for as opposed to a visual that somebody thought would be cool. Sometime manufacturers reps get involved in this process and they will say, “Hey, here’s a cool looking product.”  And they will make a lot of money if you buy it. And then they will put it all over the room and they don’t think about where it goes. And the inevitable complaints shall come.

The general rule of thumb for auditoriums is “down low” for reflective and diffusive surfaces. Where they get placed depends on more than just the room. It also gets placed based on the sound system and where speakers are bouncing off the walls, things of that nature. Typically, speakers go way up high in a room. If there’s anything up there, it’s absorption. Usually, it is relatively thin absorption to pick up high frequencies before they hit the ceilings and create kind of this weird after-ring-sheen that a lot of rooms have. So that’s kind of a general course, but what we’re hoping we’ll be doing is modeling it, finding a correction before it gets built. But my advice here is if you’re going to change a room, talk to the people who use it. If they say, “look, we want this room to be X” or “we’re happy with this room” you better be sure that what you are doing doesn’t change the way the room sounds. If you want to change it visually, that’s great. A coat of paint can do that. But don’t start putting in materials with an unknown characteristic.

By the way, the YouTube version of this is a fireside chat: How To Avoid Doing Bad Acoustics – A Fireside Chat with Seth Waltz    We have a lot of other videos on various subjects. Please watch and subscribe to get the most current videos.

 

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Copyright AVL Designs Inc. 2023+

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digital lighting board

We Told You So

When I was creating this post and video, it was obvious that only one title would do: “We Told You So!” Please don’t mistake this for arrogance. What you are hearing is frustration. We have been telling people this for a lot of years.

digital lighting board

I had to go out last week on a site visit for a client for whom we designed a variety of systems some 15 years ago. The design included dimming and lighting controls. We did video. We did audio.  We did electronic acoustics. I don’t remember everything we designed for them, but it was a lot.  Absolutely for sure, as we do with all of our clients, we always warned them “You are getting all this new stuff and, if you’re lucky, it may last 10 years.” Sounds dismal, doesn’t it?  They just got new. They haven’t even had time to play with it and now we are giving it an expiration date?  Well, if we are going to do our job right, we have to tell them that! With upgrades, and plain old “wearing out” a day will come when things will begin to fail.

So, as the end user you have to think about a lot of things. Number one, we always tell people when they get an audio console, DSP or a lighting console, which has memory capability, they have to make incremental backups to USB drives. And by “incremental” we mean at least weekly.

So, over 10 years time that will be 520 back ups!  “That’s too much work” you say.  Well, how much will it cost you if you have not backed it up and with time it, most probably, will fail and no longer be usable?  The smart person who follows through and makes the backups will be able take that file and load it into another product of the same type. This will get you up running again.

That best-practice was the good way of looking at things, right up until Covid.  The pandemic added a new urgency to those methods, but we’ll talk about that in a minute.

So anyway, let’s get back to the client I was just telling you about.  First of all, the dimming system we recommended for the job was substituted to save money.

Sadly, they bought a product that we did not want to allow on the project. Unfortunately, New York State’s equal bidding process never takes into account serviceability and long-term reliability of equipment. Experienced consultants know the likely pitfalls and will guide their customers toward better decisions. Nobody asked us when the substitutions were made on this one.

So, as a result, the dimming system they have is now failing. To add to it, all of the lighting in their room is still incandescent because it was installed 15 years ago and LEDs pretty much didn’t exist at the time.  (The ones that did exist were pretty poor.) This is now an auditorium  where at any moment they could have a single-point failure, taking out all the lighting in their room. Any single point failure we mean the dimming rack control modules.

A typical dimming rack has lots of dimming modules and they just do what they are told. They get their signals from a brain ( control module). And if that brain fails, you are toast! All of your lights are nonfunctional.

That is one of those events that we were warning you about. We have always told people to buy the rack and buy a spare control module, as well. There are 96 dimmers in it. The chances of all of those failing simultaneously is relatively slim. The chances of the control module that runs the whole thing failing is a lot higher. So, please, just buy a spare.

At the time the cost of a spare control module was a few thousand dollars  on a multi hundred thousand dollar installation. Seemed like smart move to us. You put it in a box, store it somewhere, have it available for a time,  like now, where bad things are happening all over the world.

Of course, they didn’t do any of that. The other thing they did not do was make any backup to their audio console and, therefore, they weren’t saving backup files of what is in their audio console.

They now have an older digital console that is failing. It’s sad.

And there is the added problem of signal, which is how it gets from point A to point B. We’ll talk about that a little bit more in a minute. To recap, you have these single-point failures: the console dies, audio system is down, dimmer rack, front end dies. All are down.

As well as the digital signal processors that tune their line arrays. Same thing here. Speakers are going to last a long time. Amplifiers are easy to replace, and you don’t have to have the exact same amplifier that you had when you put the system in. The DSP is very specific and requires a file load. If the DSP fails all the precise tuning of the stem is gone.

They didn’t buy a DSP  either because the idea of having backups and support is not something that school districts think about for auditoriums.

 

So, they have this equipment failing and now that it has become a critical situation, so they came to us.

They told us they had a $30,000 budget to do something but, here is a new wrench in the plans, there was Covid. With the supply chain debacle, most of the things that are needed to remedy their situation cannot even be purchased. There was the China problem, the people who went out of business problem, the “you can’t get parts for things” problem. So where it should have been doable, now our clients were faced with only $30,000 they could spend and $200,000 worth of problems.

With all of those obstacles in the way, it was time to figure out workarounds.  And we’ve been figuring out some pretty crazy workarounds for people lately to help them get past some of these things.

Workarounds are nice, if there are any.  Sadly, there will be no way out for a lot of people.

It is time to get back to some of the things we have been telling people for years and, from this point on, everybody should take this advice more seriously.

  • Get backup equipment.  
  • You just have to buy it. 
  • Do not delay.
  • Buy critical components.

Here is a real life scenario: there is an audio console with eight physical inputs on it and digitally up to 164 inputs coming in from stage boxes. I was out at another job site the other day where their stage boxes failed. That means that they have no physical connections at their console. They have stage boxes and they can’t get the stage boxes to talk to their console. (not all stage boxes speak the same digital language )

So those who have depended on only one way to get their system to work truly are in jeopardy. A catastrophe is lurking around the corner.

When the digital revolution began we would tell people “If you’re going to put in a digital console, leave your analog snake somewhere. You might want it.” I think I actually said, “Someday you might want this.”

Well, someday is now. If they listened to the advice, I could have walked in with some old whatever, like a Mackie 1604, and at least have gotten sound out of a system for them. Now they have no way to get signal from the stage to the booth because they wanted their analog snake gone. “It’s old technology. We need to get rid of that.

Enough ranting about that. So when you look at the single point failures in audio systems, you’ve got stage boxes, you’ve got consoles.

Let’s say you own a Behringer wing, which is working at the moment, and I back up files. The question is can I rent or buy a wing if I have to?

So, the first thing you want to think about is using equipment that is available on rental from people nearby who rent equipment. But unfortunately, in the bidding market, they can’t use that as a parameter for why you do or do not accept a substitute product. So, you might end up with, let’s say a lighting console that fails and in the future your files won’t go in any console you can rent. Now, being that things are DMX, in most cases you can usually get things up and running if you happen to be using CAN  that can be a little more difficult if your console doesn’t work well with the version of ACN that somebody may have installed.

But if you don’t have any of those options, you are just out of luck.  You have no lights. So, at that point you’re getting out candles or you’re getting out flashlights, which is lots of fun.

In many cases the average high school we do could have like $1.6 million worth of new equipment going into a project. And the backup equipment they ought to own is let’s say $35 – $40,000 but they don’t buy any of it. And then something like Covid comes along, which no one ever expected.  In this scenario,  manufacturers may or may not even survive.

Now let’s talk about that a little bit because in the middle of Covid (in our world we are still in the middle of it) we have multiple installations going on right now that are stalled waiting for key products to come in that can’t be delivered.

So let’s just say you had a very specific audio console that needed to be this many inputs to work with these kinds of stage boxes and let’s just say the stage boxes showed up but the console didn’t. And the stage boxes are Dante and the console you were going to get was Dante.

But now you can’t get that. So, now you have to buy another console somewhere or get a console that is Dante but maybe you can’t find one. And now you’ve got cat 5 wiring, which is great, but you own a bunch of stage boxes that won’t work with your console.

In the current climate, one of the new things is a new wrinkle beyond just backup. It’s the “which standards am I going to work with?” wrinkle. So if I’m going to work with old school DMX, which to be honest I think in a lot of applications is smart, if you don’t need tons of channels.  You won’t have to worry about a console specific ACN network and whether or not your system will talk to it, you can just hook up DMX and use anybody’s controller to get something to come on.

With audio analog snakes, they’re a great idea. Have analog backups running from your stage to your, your stage rack where, worst case scenario, you patch a bunch of XLR’s together and you can actually get sound out of things.

So, it’s kind of interesting looking back at the many years we’ve told people this and everybody ignored us and now we’re being faced with multiple people contacting us. Very recently it’s been starting to happen with “I got this problem” and  “I’ve got that problem.”

I was just at one the other day, their digital signal processor on their PA system died. They never saved any of the files. So, they don’t know what any of the filters were when it was fine tuned by a bunch of experts years ago and they can’t get the DSP that was in their system anyway. Even if they had saved the files, they are still toast.

So if you own something that is using whatever filters, patching, whatever it might be, here is your homework (due immediately.)  Create Hard copy Excel spreadsheets of settings.  They’re a pain in the  to do.  Most consoles and equipment will not spit them out for you in any fashion. But having that information such as “how is my dimmer rack patched?” in a pinch is pure gold!  How is the DSP set up in my system? Hard copies are paper copies. And I know that’s like it, it’s like, they’re saying this ?  “You must be a dinosaur talking about paper.”

Trust me, it makes sense. I had one of our who clients contacted us where their DSP failed at a site  down in Washington DC.  We had to dig out a Windows 95 laptop to open the files, but we had copies of the files that they didn’t have.  So we were able to send them a hard copy spreadsheet of all the parametric EQ settings, delay settings, all the, all the tricks that were used to tune their sound system so they could get a new DSP and get it up and running again.

Time to Be The Champion

Please, I cannot stress this enough. Be the champion. Backup, backup, backup. Back up equipment, data hard copies, these are the things that save you and get your venue running when everybody else is scrambling.

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Copyright AVLDesignsInc 2023+

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Why Acoustical Doors Drive Me Crazy

 

So today we’re going to talk about a subject that kind of drives us crazy:  acoustical doors.

In our experience over the years, we’ve designed a lot of projects. We’ve worked on many projects that called for the use of acoustical doors. Quite often, acoustical doors don’t work properly in the field. The ones that we specify are magnetically sealed, and they tend to work quite well. The ones that are compression sealed, however, do not.  

Most recently I was asked by an architect to do some testing on a project that we did not design. There was a compression sealed door substituted for a magnetically sealed door. It was testing at NIC 38 but it was supposed to be a NIC 50. Why was that? Well, the door simply could not get enough compression to seal the seals.

The results in this instance were so poor because they were using a card swipe access system that would not allow that amount of compression. So, the customer was paying for 50 and getting 38, which is a dramatic loss. 10 Points is twice as loud……

And in this particular example, it was a vocal isolation booth in broadcast, so it was a big deal. What they needed to do was change the seals out to magnetic, which can be done in the field. It is an added cost and obviously contractors would be involved.  Since it was not our project, we have no idea what they finally decided to do about it.

Why Mag Sealed Doors?

So, what I want to talk about is why magnetically sealed doors are used.

Our first example is your refrigerator. Your refrigerator has a mag sealed door on it because you want to keep the cold in and keep the heat out.  Acoustics are the same thing. A magnetic sealed doorframe, like a refrigerator door, reaches out and grabs and the refrigerator frame, and that keeps the door closed.

In the case of a door that is used by the public, it must meet ADA* requirements. The door must have the proper opening effort to meet ADA. There are some magnetically sealed acoustical doors that do and there are some that do not.  *ADA: Americans with Disabilities Act of 1990

When you get beyond about STC 45, you must go to a double magnetic seal. Most of those will not meet ADA requirements and would then require something like a motorized operator to open the door to meet ADA.  If you want high performance doors, you are going to be using double or triple magnetic seal doors and they are not going to meet ADA. Good as they may be acoustically, they are not always usable.

We’ve had some clients who have chosen to go with compression seals because of the opening force, but they are often 10 dB or more lower than their rating because they don’t compress.

We show you something in this video (starting at about 3:00 on the meter) as we look at a door online and kind of walk through how it is assembled and the type of performance that you can expect out of it, if it is properly installed.

 

 

Our base spec is always centered around IAC Acoustics because of our experience with them in the past. (A picture is worth 1000 words, right? Well, In the video above you will see this and other examples and we explain them.)  This door is an STC 43 but we have had field performance from this door closer to 47. Now they won’t rate it that way because they are very conservative, but we have had many of these in the field for quite a while and that has been what we have observed. Not only have these acoustic doors performed higher than the official rating, but they have also continued to perform that way as time goes on.  

So, why do they perform so well?  First of all, they are built completely assembled with hardware delivered. So, the contractor can simply set the door in place to the threshold and the walls and it is done. No one has to put assemble  hardware in the field.

This door also uses a cam-lift hinge system. So, the door rises up in the air as it is opened so that it lets a yield pad compression seal at the bottom expand and then it compresses as it drops. You’ve got the magnetic seal around the perimeter which really is a very high performing seal.

Double Magnetic Seal Doors

Now let’s talk about situations where you need something beyond. In these cases you will be getting into a double magnetic seal door.

Again, it is kind of like your refrigerator. When you go to pull it open with a single magnetic seal, most people can open it, no problem.

If you had a double magnetic seal, and then added to that a cam lift hinge raising and lowering the door, you might not be able to get your refrigerator open. You have probably seen small children who cannot open the refrigerator, even with a single magnetic seal.

Double or even triple magnetic seal doors are used in higher performance music spaces such as recording studios giving them up to way beyond 51 with a triple magnetic seal. The doors also weight 300 Lbs Plus.

Now, the reason I think they go with the double seals is when you get into these thicker heavy doors, you’ve got issues with potentially leaks around the seals themselves, possibly due to the doors. The second seal would be there to close that up. I am not really sure why they cannot do that with a single seal with a really heavy door, but everything above 51 tends to be double magnetic seal. Then the really high-performance doors tend to be triples.

A word to the wise, if you really want a compression seal door to work, be prepared to have to lean on it with your body weight to close it. (also not ADA compliant)  And then all of the tension when you do that is at the latch set. If your latch is the tension point for the door, it’s not holding it evenly around the perimeter. So you’re not necessarily going to get a compression seal that holds at the perimeter when all of your tension is at a latch set, which is where the mag seals come into place. The door is not being pressured to make it work.

In our opinion, mag seals are the only thing you can trust. Everything else we’ve tested has been sketchy at best. We have tested many doors over the years, we’ve only had one or two with compression seals that came anywhere close to their spec. It just happened to be a very perfect, pristine installation and there is no guarantee that they’re going to stay that way. 

Do take a couple of minutes to watch our video.  It includes further explanation concerning the compression vs. mag sealed door decision and you will see why acoustic doors DRIVE ME CRAZY!  

We hope this post and video help you avoid a disappointing result (and the frustrating and often costly need to make corrections after) as you create a sound-isolated space.

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Copyright AVL Designs Inc 2022+

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Microphones 101

Let’s talk about microphone techniques.  I work with a lot of singers. When I work with them, I am always surprised the little they seem to know about how microphones work or that they have a part in getting a successful sound in a live environment.

So, I made a video called Microphones 101 to teach how the new (and not-so-new) microphones work and how to get the best sound in a live venue.  *Watch the full video here:

https://www.youtube.com/watch?v=UCFeVznYFNE&t=15s

The first mic we will look at is a kind of beat up Sennheiser wireless. It’s a G1 series wireless with a condenser head. This mic has its own particular group of things that go on with it.

So, this mic has some good and bad characteristics depending on what you’re looking for. When you have no EQ applied to it, you’ll notice there’s some serious sibilance* in this microphone and a fair amount of low frequency handling noise.

DEFINITION: sibilance = a hissing sound

  1. The first thing a singer should be aware of is whether the mic they are using is making noise when they move it around.
  1. And the second thing the need to know is where do they hold the mic when they are singing.

This seems to be a problem for some singers. One of the events that I work at regularly involves 8 singers, all of whom are quite animated on stage. They move around a lot. They do a lot of things and, as a result, the positioning of their microphones is very inconsistent. Microphones are designed to be used at about a two to four inch working distance in front of the capsule. (i.e. their mouths should be no more than 4 inches away from the mic.)

If you take that mic and tilt it, as some people do, to a 90-degree angle, you’ll find that there is a relatively large shift in the response of the mic. Some wind noises change frequency to very low frequencies.

This image shows frequency spectrum where you can see the different frequencies being affected with lows and highs. If you don’t know that, then you are probably not a sound guy, you are probably a singer. The important thing to remember is that the position of the mic is a big deal.

The other thing with the microphone is that gain is related to the position. So, if I hold the mic just 2 inches from my mouth and then I double that working distance, I just went from 2 inches to 4 inches. That movement will cause a huge drop in level, with an attendant change in frequency response. This is what is known as “proximity effect.”

Proximity Effect

Most microphones exhibit proximity effect to some degree, some more than others. Condensers like the 865 head have a lot of proximity. And if you get really close to the capsule, it gets really kind of crazy. Then, if you get extra close to the capsule along with moving it at funny angles, it gets even weirder.

So, when mixing one of the first things we do with condensers is we typically roll off the really low frequencies by putting a low-cut filter on them. And then, once that is done, we start looking at other things as getting rid of sibilance that is on the microphone. Now the singer has a microphone that is a little more neutral, but if they back off the mic, they are gone. In actuality, when the gain drops down to 20 DB below everybody else, it’s a problem.

What I like to do, and not everybody agrees with this, is make it where if they get too far away from the mic, it turns them off. In other words, the gate just turned them off.

Why?  Well, when you have 8 singers on stage and you are trying to blend their voices (I deal with this regularly) they are getting so far away from the mic that effectively their voices disappear. You would think that the fact that they no longer hear themselves in the monitors would signal to them that something is wrong. But typically, they ignore it. So, the sound engineer has a singer who is not cognizant of what is going on. At that point, I would rather have their mic off, than having it pick up random noise from other things on stage. It is a matter of preserving the overall good of the audience’ experience.

To recap:  working distance is very important and performers need to be aware that, if the working distance is not reasonable, they will not only have tone problems, they will have an, “I left the mix” problem.

Working distance is the first thing to look at. The second is a consistent use of the microphone. One of the more fashionable mic handling styles with some singers, first popularized by rap stars, is cupping the hand over the microphone.

Cupping your hand over a microphone does a number of things.

  1. It changes the frequency response.
  2. It changes the gain.
  3. It changes a lot of things.

As you watch the video, you will notice the big boost around a hundred, two hundred, 1K 2K, and  that it gets kind of nasally sounding. Part of that depends on how far you cup your hand. This technique can go from several stages of partial covering till the mic is almost completely covered.

If I wanted to fix these things, I could. If the singer wanted to use the mic the same way all night, I could kick in a compressor to level out the gain problems I’m running into because of all of this. But if that singer suddenly decides to go back to holding the mic normally again, everything changes. Those abrupt changes just do not work well for those of us who care about the overall mix. This is just one example of the problems that happen with singers on stage who inconsistently handle the microphone, not to mention handling noise that also goes on. Add to it that you have eight singers all doing this, you have a lot of unpredictable modifications in the mix.

So avoid the gain changes that occur with microphone working distance. If you are going to be moving around a lot, learn to move your body with your head, which means you cannot have your head going in different directions than your microphone.

Handling a microphone is like playing an instrument.

It is kind of like playing an instrument. If you’re a guitar player, your fingers are supposed to be on the strings when you are playing chords. So you really have to work on this. Many singers seem to, at least the ones I get to work with, ignore all of this. And then they wonder why there are no altos. There are no tenors. There’s no, this there’s no that. The other ones that I really don’t like for other reasons, when I turn this compress around, before I do, this are the ones who eat the microphone.

Now in this particular situation, the gain of the mic is already too high to get away with this. So, I’m clipping the input. Now I’m just backing off that. And then I’m using the compressor and I’ll have to use some makeup gain to get back the gain I’m reducing. But when you get really, really close to one of these microphones, I will have to turn the EQ back on to try to fix the stuff that’s happening by being really, really close to this microphone.

So, there’s a lot that goes on with the 865 p microphone when you get really close to it. So, you end up with a curve that looks pretty bizarre when you get really up there. That sibilance peak, while it’s still there it is less prevalent, and you get all of this low, mid frequency energy going on. The way you fix it is that is you use the mic properly.

So, this is one style of microphone. Let’s talk about one that is radically different. And if you have singers who, for example, like to cup their hands over the mic, is a better choice.

It is a Beyer TCX 58, which is their kind of version of an SM 58. This mic with EQ off is very neutral sounding. Now, if I were to cup my hand over the microphone, there is nowhere near the dramatic effect you get with the condensers, which is one of my contentions. A lot of times people will walk in and they’re used to doing something with the mic they used to use. Then the sound company shows up with a different kind of microphone and hands it to the same artist and they decide to do what they always do. And they don’t realize that they’ve gone from that to this.

And this is now a significant problem. Now you’ll notice also that this Beyer TCX 58 mic, although it has a lot of proximity effect when you get really close to it, it doesn’t have nearly as much. So, the shift with gain is not as hard to manage. If you wanted to work it out with a compressor, you can actually get the compressor to manage the gain a lot better with this microphone.

So you get on this mic and then when you back away from it, it turns you back up. So you can get some things that aren’t nearly as dramatic as you get with proximity effect on a different microphone. The other thing with this one is if you do wanna put in a low cut filter, it solves the low frequency problem pretty much entirely.

Singers => Learn Your Hardware

So, I guess what was trying to get across in this short video is that singers really need to learn their hardware.

They need to learn what works, what doesn’t work. They need to learn how to follow themselves around. And if they’re really singing, dancing type folks, they either have to go to a headset or they have to do something else. But when you’re dealing with handheld microphones, you have a responsibility to make sure you’re rendering properly. And, if you don’t, the sound guy can’t deal with that with eight people.

Hey, where did I go?

So wondering why you disappear in the mix is something you shouldn’t be doing, which is why I do this thing where, if you get away too far, in my world I just turn you off. And when you have a bunch of singers on stage and you’re gating them all heavily like that, there is obviously band noise on stage, You have to gate it within that realm to get that to work. But what turning some voices off prevents is picking up a lot of distant noise that you really don’t want in your mix.

So, gating is one good way to solve that problem. And I’ve noticed the singers, at least the ones that I have worked with, they often don’t even know that they left the mix, which shows that they’re really not paying attention …but that’s a whole nother story. And we can talk about that, maybe, some other time.

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