BLOG

Condominium Sound


In the past few years, we have noticed an upswing in the construction of higher-end condominiums. The people who move into these spaces are typically downsizing.

These people are moving from single-family homes into spaces that have residential layouts but are actually single-story dwellings stacked in multi-story buildings.

Many people that have moved into these spaces complain about noise. They are troubled by noise from hallways, from adjacencies, from outdoors as well as from overlying and underlying tenants.

These buildings generally have been designed to typical IBC Based state building code, which requires an STC of 50 (airborne noise control) and an IIC of 50 (Impact Noise Control i.e. Floors).

So, the question that frequently comes up from the architects we work with is “why, since we designed to the standard, are we getting complaints?”

Why the complaints?

In examining the problem, one missing element in these newer builds is the lack of what we in the acoustical industry call “masking” noise.

Masking noise is background noise such as traffic, HVAC, appliance noise, neighborhood noise. Masking helps your ears not notice outside noise sources. Bottomline, these new condos are just too quiet inside.

The quietness is primarily due to more recent energy codes.  Older apartment buildings and older houses had windows that would leak heat. Where heat leaks, so does noise. New high R buildings do not leak heat and were by default, better at keeping out noise from outdoors.  

Appliances have become significantly quieter. HVAC systems, dishwashers, refrigerators, and other household appliances are now close to silent.  In the past, they offered a good level of masking noise in a residential environment. Not so, anymore.

In older buildings, noise from outdoors would mask other sounds, i.e. you didn’t hear the neighbors so much. People also accepted outside noise as “where I chose to live” noise. Not so much in a luxury condo. People want it to feel like they don’t live so close by others.

Standards are out of date.

It is our belief that the standards are out of date. Privacy is determined by a sum of the STC or IIC of physical separations added to background noise. If background noise goes down, construction quality must go up and, yet, this relationship is not addressed anywhere in the code. Background noise is not considered as a factor.

In our opinion, the current standards are off by approximately 10 points when it comes to owner satisfaction. This has been proven in buildings that we have tested. In the ones that were designed at least 10 points above standard, the residents are not complaining. When it comes to the ones that are built at the code standard? People are complaining about the noise.

Beyond STC/IIC

STC and IIC standards do not include low frequency noise, for reasons that will be the subject of another article.  

A major complaint we are seeing in a lot of the newer, higher-end condominiums are “elephant noise footfall” complaints, and TV action movie noise when the neighbors have home theater systems.

All of these low frequency sounds fall below the STC and IIC standard.  To the chagrin of tenants, a space can test to “spec” and still have these low frequency issues. If you have active people moving around upstairs it can sound like a herd of elephants, which can be considerably troubling.

*Design to control low frequencies is challenging but can be achieved, when done with care.

MINIMUMS

State building  code standards are the minimum requirements. The STC and IIC values the codes  reference are residential multifamily minimum, which may be acceptable for a  college apartment or short term lease , but not a condo high end condo.  And the codes are based on an expectation that a wall or floor structure in the field actually performs like the lab test, which isn’t a realistic expectation.

In the lab an assembly is 100% airtight, There are no electrical outlets, recessed lights, ductwork penetrations etc.  In the real world, performance is at least 6dB, often 10 dB lower. (To your ear, half as good.)

Solutions

There are solutions but they are not the common methods. Floors have to be stiffened up beyond required structural norms, resilient materials added and, in some cases, low level electronic sound masking added.

TV’s cannot be attached to demising walls, or demising walls have to be isolated from vibration.  

Some hard floors have to be swapped out for softer options.

Penetrations and methods need to be changed and treated to be air tight, recessed lighting, HVAC, ducting, bathroom exhausts and other systems need to be built differently than the norm.

These are just a few of the issues. The truth is that all solutions to noise problems will raise costs.

Before you move, ask questions and get guarantees about acoustical  performance.

Read More

Room Acoustics – Are You Sure That Your Acoustics Are Really Bad?

Room Acoustics

When we get involved in projects to renovate auditoriums lecture halls or classrooms, one of the common complaints we hear from people is “we have bad acoustics.”

Guitar band

Now that statement can have a whole plethora of meanings. So, we start probing. “What exactly do you mean by ‘bad acoustics?’”

As you can imagine, the answers we get back are all over the place. Some people think their room is too live. Some people think their room is too dead. Same room! Some people think that the room has zero sound quality. There is no consistency in what people call “bad acoustics.”

There are rooms that in our expert opinion sound quite good while, in the client’s opinion, the sound quality is bad. There also are rooms that we think sound absolutely awful, but people love them.

Here is a good example: We visited a church that has an exceptionally long reverb time in the main sanctuary – way too long for the spoken word, way too long for any kind of contemporary music – yet, the members just love their acoustics. Reverb time in that room was two and a half seconds in the mid-band, which is really excessive.

The reason they love the acoustics is that they have a choral group and a big pipe organ. For that purpose, the room sounds surprisingly good with a big full sound.

It was just that the listeners were not be able to distinguish the words that the choral group was singing. That, apparently, was not a priority for them. They were happy with it just the way it was.

They wanted better spoken word, but they would not sacrifice any reverberation to obtain it. They wanted a sound system to fix it all.

We have been in other venues where the clients say they “like the acoustics,” yet the room is dead as a door-nail. Often, in those cases, the reason that they like the acoustics is that the primary use for the room is for something like lectures.

However, when they stage a musical event in that same room, it is dull sounding. That is why, when people first say they “like” their acoustics, we ask more questions. Until we know more, we cannot really trust that we know what they really mean.

So, the concept of “good” acoustics is not a standard. There are a lot of standards in the acoustical industry defining what appropriate acoustics are, but for specific uses. A room with good metrics may not be perceived as “good” at all. This is especially true when you get into multipurpose rooms that have more than one function. When the rock band gets booked into the opera house, bad things follow.

Whose Fault Is It, Anyway?

Another real misplacement of blame happens when people add to their “bad acoustics” complaints a discussion about their sound engineer. What they are really talking about is the person running it. But the problem may not be the sound engineer at all. It just could be the performance of the sound system. Or, it could even be both. Obviously, the sound engineer is the final determiner of outcome in any space where sound is being mixed but the outcome will only be as good as the design of the system, and how it works with the room acoustics.

Sound engineer operating a sound board.

Sound systems must be designed to work with the room acoustics, not against them. Over the years we have seen many sound systems that seem to have been designed completely ignoring basic physics, the layout of the room, the reverb time of the room, the reflections and echoes in the room. Hate to say it but they “slapped something in there” with little thought.

Is the only “good seat” where the sound guy sits?

Sometimes the “good seat” is where the sound guy sits. So, you have a sound guy who is sitting in a location mixing and he thinks he is doing a good job, but the sound he hears is completely different than the sound in the rest of the room.

So, back to the initial complaint, there are a number of things people are not understanding.

  1. The sound engineer needs to be located where he/she actually can hear an average (ideally) of what everybody else is hearing. Or they have to learn how to translate what they hear where they are.
  2. The sound system has to be designed to work with the room’s acoustics.*

*Some sound system companies, the ones that just put in speakers and install equipment without doing any kind of analysis, are not skilled enough at placing loudspeakers and tuning a sound system to get it to work well. In these situations, the sound engineer may not be the one at fault.

So, after speaking for a while with our clients about the difficulty they are having, we arrive to an understanding that…

  1. There is no one room condition that is going to make them happy.
  2. There is not a different sound system that is necessarily going to make them happy.
  3. It is not all the sound engineer’s fault.

…now we can talk about some real solutions.

How do we make a bad sound situation better?

When we design physical acoustics using diffusors, absorbers, reflectors, and various types of structures to guide the way that sound behaves in the room, there are limits to what can be done.

Often, there are budgetary restrictions to what can be done.

Some of the things that might work really well acoustically could be extremely costly. The cheaper ways of adjusting a room acoustically can be kind of ugly. They can look more like you have just randomly attached a bunch of things to surfaces instead of designing a space when you are doing a renovation.

STEREO

So, it can be challenging. First, you must decide what the goal is. What is the room designed for? Speech? Choral? Orchestra? Contemporary music? When you do adjust physical acoustics, you end up with one condition and that condition is the way everything renders in the room. Remember that rock band in the opera hall? …… Not a good option. Better to find some middle ground.

When it comes to the sound system, there are similar decisions to be made. Certain aspects of sound systems design conflict with others.

The idea of left and right is wonderful if you are sitting in the center of the room. Anybody sitting in any seat other than the center line will only hear some of what is on a side of the stereo pair if the sound is panned left or panned right.

If you go with a center cluster, it can be very intelligible and sound great for speech, just as long as it covers all the seats.

There are a couple of problems with using center clusters, however. One is that they are mono and one dimensional, lacking any sense of breadth. Ears hear energy from both sides of the head and the way that energy arrives to your ears gives a sense of warmth, a sense of being enveloped by the sound, which is an important part of the experience. Center clusters tend to be dry sounding. They can be very intelligible but not very musical.

Then you move up to left – center – right, which is a commonly talked about concept that most people do not really understand. In a left – center – right with stereo capability you have to maintain panning consistency so that when something is panned to the left, the entire room still hears the sound and it is perceived as coming from the left.

If your room is wide enough, which most are, there is a time delay problem with trying to send sound from the far left side of the room to the far right side of the room when the far right side of the room has loudspeakers arriving much earlier. So, the way you manage this is your center system ends up having multiple elements and becomes part of the left and part of the right with time delays applied to correct for offsets distances.

In some rooms this arrangement can work fairly well, but the setup and tuning of a system that is true left – center – right with stereo capability is not only complex but more expensive because you practically triple the number of elements required to accomplish the goal. Consequently, what most people tend to do, at least for sound systems in multipurpose rooms is a left – right system that is actually mixed as dual mono.

Comb Filtering and the Haas Effect

Most of the time you never really pan anything full left or full right, correct? You have to have both systems creating the same signal which, inevitably, will cause some phase problems. Depending on where you are sitting you will be hearing both sides of the system somewhat out of phase with each other. The effect that occurs is called “comb filtering.” When that happens, if it is done poorly the room can sound muddy.

So, it requires a lot of skill in placement of those loudspeakers. You must look at time delays to various seats in the room while trying to maintain something known as the “Haas Effect.

The Haas Effect has to do with the arrival time of energy from two locations to a particular seat. If you are within the Haas Effect, (which various people disagree about whether it is 30 milliseconds or 50 milliseconds) the sound can still be good, even though it is coming from two locations from the same sound source. Once you get outside of the Haas Effect timing, a lot of destructive things happen, quite audibly.

This is all a simplified explanation there is a lot more going on……

So, this is the first segment regarding the basics of room acoustics/ sound systems.

Copyright AVLDesignsInc 2020

Want some supplemental reading? Go to => Auditorium Acoustic Options

Part 2? Coming soon!

Read More

RDM – Remote Device Management

RDM – The LED Conundrum Part 2

Let’s talk a little bit about RDM. RDM (remote device management or remote duck management) is a way to remotely change settings on DMX/RDM lighting fixtures. 

In case you missed the first installment of this series : The LED Conundrum Part 1

What you are supposed to be able to do is to plug a lighting fixture into a DMX/RDM certified network and have the lighting console identify “Oh, that’s this kind of lighting fixture. It requires this many DMX channels and is currently addressed to this DMX starting address.”  You then would be able to remotely change that and other information. 

You are supposed to be able to remotely change the mode the fixture is running in, so if it was running in RGBW and you want it to be running in some other mode,  you should be able to remotely change that. You are supposed to be able to remotely change the DMX starting address. (Can you tell that this “supposed to” treatise is leading somewhere…..) 

Yes, you are supposed to be able to remotely change other factors, too, like special effects and things within the fixture. 

When you take a company that is, let’s say, probably the largest console manufacturer in the world in the lighting industry and their DMX implementation is reportedly compliant to the standard, and you hook the fixture up to the system,  it is supposed to respond with  “Hey, hi there fixture. What are you, what are your parameters? I want to change your starting address. Let me do that.”   

That superb console manufacturer is what we use as a standards reference.  We find that some manufacturers’ fixtures just don’t show up or if they do show up, they don’t show up with all the correct information or they show up with some of the information but don’t let you change it. 

So, here are just a couple of examples of what we ran into when we hooked up a fixture to one of these consoles. 

The fixtures shows up and it says to the console “Oh, that’s an LED fixture. It’s operating in 16 bit mode, starting on address 10 and it requires 17 channels, whatever it was.”  What kind of fixture? “Unknown.” It really didn’t work properly. 

So, I went into my console library and found the fixture since I actually knew what it was and the system wasn’t telling me. It said, “it is a fixture that does this stuff” and once I pulled down its profile, it worked fine. However, it would not allow me to change it. Can’t change start address, I can’t change it from 16 bit mode to 8 bit mode, et cetera. 

With other fixtures  that I’ve tried from various manufacturers, some of the data did not show up at all. Some of them show up with random issues when you try to RDM search or flash them on a network, all kinds of problems. (Let’s not even talk about house lighting manufacturers where you put everything on a network and nothing works. Talk about a disappointment.) 

So RDM is an interesting theory, if the devices out there were truly compliant.  So RDM obviously can send the data back and forth. The problem is that a lot of people are not fully implementing it and are not sure why. 

We don’t have access to every console on the market so there always is the possibility, since I’m not a real like digital protocol wizard, that some manufacturers have certain data packets that they have designed to only send to their own stuff.  If that were the case it would seem to be a very shortsighted way of doing things. 

If there is anybody out there who knows more about this, I’d be curious to hear your take on it. I have had many  talks with that really big lighting manufacturer to find out if they have any ideas, too. In the past when I have talked to them about it they’ve said, “Nope, we’re not trying to block out anybody else’s stuff. Their product just doesn’t work properly.” 

Bottomline, for someone who needs to use RDM, it can be a nightmare. Let me give you a picture of what you could run into. 

HOUSELIGHTS

Let’s just say you put up a new building and there are a hundred house lights and they are all DMX/RDM (supposedly). And the electrical contractor you hired didn’t check the firmware version, didn’t test the fixtures, didn’t do anything which he was required to do under the specifications before he put the fixtures in the ceiling. You come in and try to find the fixtures using RDM and you find that, let’s say 50% of them don’t respond. 

So the question becomes, are 50% of them defective or are they just not set up properly? Now you have to battle through that. Sometimes you have to crawl into the ceiling, which can be fun if the ceiling isn’t something you’re able to crawl into, and manually find a way to address these fixtures.   

This usually means taking them off the network and using a handheld controller, which often with a single fixture, when that controller is available from the manufacturer, will let you address their fixture. 

Sorry to say it but that is what you may have to do. Maybe their fixture isn’t even designed to work with the world of entertainment lighting and is only designed to work with their handheld plugin. Not such a good thing. Our recommendation for house lighting is to make everybody address every single fixture and test it before it ever goes into the ceiling. It is extra work for the electrical contractor, but you can see that the alternative can be a nightmare. Testing first is much less work than taking the ceiling apart later. 

THEATER FIXTURES 

Now, let’s just say, on that same system, you’ve got say a hundred theater lights form  three manufacturers and they’re all supposed to be RDM/DMX. Now, when you plug them all into your data network and you start looking for them, only some of them show up telling you what they are and how they’re addressed.  Hopefully, some of those you can actually remotely fix. Wonderful. But then you discover that a lot of the other ones, which are from different manufacturers, tell you nothing at all.   

Now you will have to manually address those, physically get to the fixture, get to the menu, set it up and address it. Then find a library profile for it to work. 

That gets you going but in  the future, if somebody wanted to remotely change the setup because of the way they want to run a show, it is not possible. You are stuck. 

One of the key things to know is that if someone’s going to end up with a system where they cannot remotely address certain fixtures, they must be made aware of that in advance. 

One thing we recommend highly, (even though in the professional world this would seem odd), is to physically mark the original DMX address and DMX universe on every single fixture. Labeling them will tell the user that, “Oh, this fixture was on universe one channel 250 when it was originally installed, which means if I just plugged it into universe 2 it is not going to work. 

If I plug it into universe 1 and I’m trying to call it up on channel 300,  that also is not going to work.” And they’re going to have to manually readdress that fixture. Also mark on the fixture “does not RDM” so they know to set it first before use. 

Sometimes you just have to mix products and, unfortunately, the end user is left dealing with the problem, but they need to be made aware. In the public bid market, there is often the “or equal” clause. 

So when a fixture says on paper that it is RDM, you are expected to believe that. Sadly, there are times that it turns out to be completely not true. At other times, it turns out to be partially true. Some of those problems are really hard to address because they are not consistent. 

My advice: buyer beware. Test before you buy. 

We do. 

Copyright AVLDesignsInc 2020

Read More

Video Conferencing

Video Conferencing – STAY OFF THE SEESAW

At a time where video conferencing is way up, awareness of the need for technical quality in those online meetings has also increased.

Given a choice, many people would rather not meet online. But when there is no choice, why not reduce frustration and make it a more enjoyable experience?

Today, I simply want to address how to make online meetings sound better.

Video conferencing tips to help your online meetings sound great!

This afternoon I was sitting through yet another online conference and listening to relatively horrible audio. 

The primary factor causing the audio to be so irritating was a lack of understanding on the part of participants.  They just didn’t get how the audio component in video conferencing software actually works. When you think about it, why should they?

Here is a brief explanation of how things work in the app-based “Video Conference World” that should help. 

“One at a time?”

Video conferencing software is set up for one person to talk at a time. It is not a party line situation, like it would be in a real conference room where anyone can talk at the same time and still hear others who are talking.  

These online systems are set up to feature just one person talking at a time. 

And, of course, that is a problem. When you are in a video conference room, the tell-signs of who is about to say something are just not there.

Get off the seesaw.

Video conferencing kind of works like a seesaw. Only one person can be at the top. The other person must be at the bottom.  One person talks, the others listen.

Going back to our video meeting scenario, something happens at the in-between as the next person speaks up. At that in-between moment, each person is reduced in volume for the system to transfer from one to the other.

Video conferencing from home has its challenges. Barking dogs, background noises, doorbell unexpectedly ringing... things happen! This little dog wants to get in on the show!

To add to it, even if only one person is talking, should an unplanned noise occur in the room – rustling papers, dogs barking, etc. – the software will think someone is talking and will take the volume from the true orator and try to give it to Fido. 

Background noise is certainly one of the reasons they added a mute button to the software in the first place.  When people leave their microphones un-muted, any little noise, whether it is their own breathing, the whir of an air conditioner, or a knock at the door, makes the system think that you are taking over. The featured person who was talking suddenly is reduced in volume while the system tries to decide if you are going to continue or if you are going to stop.  

If the noise interference ceases, the software raises the level back up so that the person who was really talking can be heard again.  How often have you been in an online meeting when sound interference occurred? That is when people in the meeting will chime in “Can’t hear. Will you say that again?” We have all been there, haven’t we?

Push to Talk

The solution to this audio problem is to use your mute button a lot.  Most conferencing software has a “push to talk” mute capability built in. In the better systems, if you mute your microphone with your mouse, the space bar of your computer then becomes a push to talk button.  

When you press the space bar, it will temporarily unmute you while you talk. As soon as you let the space bar up, it will mute your microphone again. So, for the sake of all of us out here, please use the bar and mute your microphones when you are not talking. 

Friendly note to the conference administrators: each time you start a new meeting, remind the participants to mute themselves and that they can “push to talk” when they want to speak. Your meetings will flow more smoothly.

 Why is there an Echo?

Why do we hear an echo? An echo is the result of someone talking, then the sound goes to the far end (delayed) and is played back through a speaker. The speaker output at that end gets picked up by the microphone on the other end and is repeated back and forth. It is audio ping-pong. So, how do we get it to stop?

Echo cancellation software is in the app and it makes a one-on-one situation work well, but if everyone has their mics open and speaker volumes turned up loud, there are just too many sound sources for the app to always fix.

When your mic is muted you will eliminate echoing because echoes do not occur when just one person is talking.  In other words, if every meeting participant remembers to mute their mic, using the bar when it is time to speak, echoes will be almost non-existent.  

But what if you cannot unmute? If muting is not possible then reduce the volume of the loudspeaker on your device or use headphones so that extraneous sound will not be produced and picked up by the speakers.

The bottom-line is that each video conferencing system, be it Zoom, WebEx, StarLeaf, Google Meet and the like, has varying degrees of audio quality but none of them can fix errors that are created by the users.

Only you can prevent bad conferencing!

AVL Designs Inc. =>> Video Conferencing Services

Copyright AVLDesignsInc 2020

Read More

Stage Safety Basics For You To Put Into Action Today

Let’s have a little talk about stage safety, specifically in relation to use of any kind of stage rigging, lighting or other equipment in a theater.

Note * This is not an exhaustive study but simply a “basics list.” We find most schools don’t even have the basic level of safety procedures in place.

Stage safety basics for all theaters including high school auditoriums. #tips

When no one is monitoring the stage systems, accidents could easily happen and most of them are avoidable. As we visit schools to review their systems, we often discover unsafe conditions which have not been addressed and that no documentation has been created to let anyone using the stage know that a dangerous situation exists. That is never a good idea.

Start With Stage Changeovers

There should be procedures in place, with sign-offs, indicating that people have checked the status of their contribution to the stage before a show starts. People should not be randomly building sets, attaching lights, adding microphone cables, lighting cables and the like without certifying that they have first done a proper, coordinated safety check. That check needs to indicate nothing is snagging, everything is attached with proper load-rated hardware and that everything is in balance. This must be a written document, accessible to all on stage. It is imperative that anyone using the stage review this safety checklist first, prior to use.

Failing to maintain this documentation is like loaning a car to someone without telling them the brakes don’t really work so don’t stop suddenly. “Oh, and the gas gauge is broken and I’m pretty sure that the headlights don’t work.”

Stage Checklist

There should also be a form that gets logged and signed off at the end of a performance or rehearsal that indicates the condition of all stage systems.

A sample basic checklist:

  1. All rope locks are engaged.
  2. All of the battens are properly counterbalanced.
  3. All battens are free from any tangled wiring or items that could impact adjacent battens.
  4. All lighting circuits are plugged and checked.
  5. All fixtures that are assigned to the show plot still work.
  6. All fixtures have safety cables.
  7. No defective wiring was found.
  8. There are no stage weights or anything in the locking rail that could cause problems.
  9. There are no trip hazards on stage
  10. Etc…… There are a multitude of things that should be on a sign off sheet depending on the show, venue, and special conditions. 

Where a checklist alone does not suffice to indicate a safety hazard, you may also need to rope off, lock, or mark safety hazards that can’t be corrected immediately.

Safety Procedural Manual

There should be a Safety Procedural Manual for every stage. Some really good ones are available online for review. Maintaining stage safety protocols is not just a matter of making a checklist of two or three things. There are pages of checklists items that should be followed every time you change anything for show, or plan and build a show.

Define Your Team

You should also make a list of authorized personnel. Not just anybody should be able to go up on stage and perform work or run rigging systems.

If you can’t do the math to figure out the load on a batten, then you shouldn’t be allowed to touch it.

If you can’t walk up to an arbor and by a quick visual and manual inspection of the operating lines determine whether the set is in-balance or out of balance, then you shouldn’t be opening a rope lock at all.

These procedures should be in the training manual. People who have been trained should be certified by the school.  Letting just anybody do anything on a stage is a recipe for trouble.


Let’s look at  an example of what can happen.

You walk in and need a curtain that is flown out  to be  moved down towards the stage. The person who used the stage last, for some bizarre reason removed a bunch of counterweights from the curtain set arbor after it was up. That arbor is light and the curtain is heavy. You don’t know enough to recognize what has happened, so you go ahead and release the rope lock causing the curtain to come crashing down towards the stage.

There are a couple of possible outcomes this un-safe scenario may produce. In the case of a stage curtain, when some of the weight of the curtain  lands on the stage, it slows down. If you’re  lucky it stops before the batten it’s attached to  hits anybody in the head.  But, sadly, things could go the another way and it will injure somebody.

Lack of safety procedures and not insisting upon sign-offs puts people in physical jeopardy. Sign-offs basically say “Hey, show’s over. I checked all of the sets, everything’s in balance [i.e. safe] so that when you release the rope lock, nothing will start moving much by itself.” Insisting on official sign-offs makes it safer for non-skilled people to use the stage.

It is still not a good idea to have non-skilled people working the stage but, at least, it is safer with a checklist.

What if there is an electric cable that is frayed, a light was flickering, or the sound system was making a humming noise that it never made before?  Log It. There must be a reporting procedure so that when anything like that is found, it will be logged and communicated in writing to someone who can check into maintenance.

Note: Procedural manuals are also needed but that is another topic. How sets are  built, use of paints, special effects, power tools, fall protection, use of ladders, electrical safety, issues with strobes, lasers, etc…. will need to be in your procedural  manual.

Here is a well-thought-out manual by Southern Oregon University, available for you to read (not plagiarize): Sample Stage Safety Manual

Stage Rigging Inspections

You must have inspections on a regular basis by qualified professionals. These inspections will identify where there are issues and other problems that a general checklist cannot address. ESTA and ANSI standards require inspections of counterweight manual and motorized rigging that need to be performed annually and or biannually. On motorized rigging and stage lifts, the inspectors have to be versed in the specific system, general knowledge does not suffice.

If these inspections are not being done, you’ve now left your people “using a car with bad brakes.”


Copyright AVLDesignsInc 2020

Read More

Auditorium Acoustic Options

In the past, auditoriums were generally purpose-built. Opera houses were designed for opera. Orchestras often share the opera house by adding a stage shell that would aid the orchestra acoustically.  

photo courtesy of Pixabay

Lecture halls were designed for speech. Movie theaters were designed for sound reinforced by audio from loudspeakers.  

Churches were designed for various styles of music and use. Some spaces were built around the required characteristics of a large pipe organ.  As liturgical spaces are being repurposed for contemporary music and changing congregations, the results are often not very good.

Multipurpose auditoriums were never really multipurpose.

They were a middle of the road compromise.

When preparing to design a space from an acoustical point of view, the first question that has to be answered is:

What type of performances and uses should it accommodate?

Next Question:

Can I target a style or do I need variable acoustics?

Generalized Examples:

  • Unaided speech requires a quiet room, lower reverberation time and strong early reflections.
  • Orchestral requires a  longer reverb time, extended bass response, and a diffuse room response.
  • Contemporary music driven by sound reinforcement requires a completely different room character. In order to allow the sound system to control the experience, the room has to be subdued.

Personal Experience:

Dead Room

Live music can be disappointing in the wrong environment. I remember once I was working with a jazz artist and the auditorium we were booked in was entirely covered in thick fiberglass wall panels. It was dead as a doornail acoustically.

Even when using reverb effects, the room still sounded wrong. The reverb was coming from the PA and the stage monitors, not the room. The side and rear walls were absorbing everything, not adding anything to the sound. Not a great experience.

Overly Live Room

I also remember hearing a favorite artist (Jazz/Bluegrass) in an opera hall. The room was so live it was totally muddled. The sound system could not correct for the overly reverberant room.

How About a Variable Room?

If you build a room with no acoustic variability, as and audience member or performer you are stuck with what you have.

Acoustical Variability to some degree can be accomplished with wall covering drop curtains, rotating walls with various materials, and other options. Physical options can be costly and they can take significant manpower to change for each event type.

Electronic Acoustic Architecture

Most people are familiar with movie theater surround sound. THX, Dolby, Dolby Atmos etc…. These systems create spatial locations for sound sources using a multitude of speakers, each receiving specific information to simulate where the sound would be coming from, or to extend the “feel” of an environment.

While these systems are great for movies, they aren’t deigned to work  with a live musical source.

Fortunately recent advances in technology have made it possible to go beyond surround sound into fully simulated live acoustic environments. Imagine you are performing in a relatively plain room with a medium reverberation time and not a lot of lateral energy. Walking the seating area, you find that there are dead spots and changes in frequency balance. Your ensemble sounds a bit thin and lifeless.

Like A Concert Hall

What you want for your ensemble is a much larger room with elegantly tailored wood and brick surfaces, diffusive in nature like a concert hall. Features like these are what makes concert halls concert halls.

Imagine, now, an electronic acoustic system that can create the sound of the room that you are not in.

This Is How Electronic Enhancement Works:

  • A series of prearranged microphones pick up the natural sound of the ensemble, organ etc… from a suitable distance so the sound is well mixed. This sound is then processed by a complex computer algorithm that simulates how the sound would behave if it was occurring in a simulated room. This sound is then precisely distributed and tuned to small loudspeakers located to simulate the room you want to mimic.
  • Room tunings and character can be changed at will. To the audience, it is entirely natural.  It just sounds as if they are in a different room.
  • When the orchestra takes the stage, the room gets larger and has added bass extension. The choral group gets a longer reverb time with added midrange clarity.  For speech, the system switches to a voice lift mode and can improve intelligibility.
  • All of this is controlled by  simple presets: Choral, Organ, Speech etc…

In order for electronic acoustics to work, the ROOM itself needs to be designed carefully from an ACOUSTIC standpoint, but in a different fashion.

Discrete echo has to be controlled. The enhancement system works with the room acoustics, but cannot cancel out physical acoustic defects.

Successful implementation of electronic acoustics requires coordination of the system elements with lighting, ceilings, walls, HVAC, plumbing and other elements throughout the design process. HVAC noise has to be very carefully controlled.  Led lighting (much of which is now fan cooled) has to be chosen and placed very carefully relative to microphone locations.

The Physical acoustic conditions have to be designed to work with the system. This is not a sound system, it is an acoustic system and placement of all elements are critical relative to the room in which it is employed.

The results are well worth the effort. Performances are enhanced and audiences experience an enveloping detailed sound quality in auditoriums that were previously not.

Copyright AVLDesignsInc 2020

Read More