Blog Index >>>

Auditorium Acoustic Options

Condominium Sound

LED Conundrum Part 1 – LED Theater Lighting

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

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?

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What is The Difference Between a Consultant, a Contractor and a Tech?

The best way to define what a consultant is is to begin with defining what it is NOT.

Over the years, I have functioned in all three positions – consultant, contractor and tech – so, from experience, I am able to describe the differences for you.  (Currently, by the way, I am a consultant.) First, let’s look at what a theater technician does …

Theater technician


A theater tech is skilled in operating a particular aspect of a production. The areas of specialization include: sound engineer, sound designer, lighting tech, lighting designer, scene designer, software programmer, etc.

Typically, as a theater technician, you are in control of your environment.  That means that you take care of emergencies yourself. You can plan the show the way you or your theatrical director want it to be and you get blamed for anything that goes wrong. You are usually using equipment that you have asked for or, in some instances, what the venue supplies. In the latter case, the theater tech assesses and determines whether that existing setup is adequate to do the job.

If the system is a permanently installed system, as the theater technician you will customize it for yourself. You are responsible for labeling, groupings, storage, and locations for gear. You determine stock levels for spare cables, parts, and accessories. It all falls on you.


A contractor is someone who either designs and builds their own work or they submit a bid to complete work that has been designed by others.

When you are a contractor, you are limited to the product lines that your firm is authorized to purchase.  In some cases, there are manufacturers that give you special deals, such as extra discounts, or where they give you incentives such as “free stuff for buying other stuff.” There are also minimum purchases you are expected to make each year from each manufacturer to keep your franchise. Being eligible to receive perks can influence what the contractor offers on a project.

On “design-and-build” work, the contractor has to decide how much time to spend on the “design” aspect. Will they spend time building CAD models, testing products they have not used, arranging demos, learning software and so forth?  The best contractors are thorough, and they charge for it in their price.  Some, on the other hand, let the manufacturers do the design work for them. Hmmm, I wonder what products that manufacturer will use ……?

Most contractors have product lines that will fill many needs, but they may not have the best solution for a specific project or task. On each job, they must decide whether to shoehorn in what they have on hand (or need to use to meet quota) or get what they need from a secondary source.

Many contracting firms have personnel who are installers, not technicians. They are good at running wires. They are good at hanging things. They are good at connecting things, but they are not skilled theater technicians. They are not the people you want doing final setup or training on systems, which takes specialized know-how.

The better contractors have system finishers and trainers on staff but, first and foremost, know that contractors are about getting work done.

It is hard for them to justify freeing their people up to learn new skills or learn a specific console or device, etc. The best contractors realize that, to assure excellent results, training is a must. Many contracting firms do not take the time to do it.


Consulting is a hard concept for some people to understand.

The end user says to himself: “I want new gear, right ?  I saw this list on the internet. I just need to buy the stuff. Why should I pay someone for help when they don’t sell anything?” 

The architect or engineer may say – “Why should I pay a consultant when a vendor* will write me a free spec and one of our drafters can do rough drawings? Free is good, right?”

*The vendor (who is not being paid) creates a bill of materials, possibly a sketch, and hands it over to the engineering firm. They do not spend much time on it because it is FREE. The engineering firm does not necessarily understand what they are looking at and cannot tell if they are the correct selections for this specific job. With no real way to evaluate them, they still go ahead and transfer it to drawings. Oddly enough, the engineers get paid for the work even though they did not do it.  FYI same thing happened with lighting, kitchen equipment and other aspects of projects …….

When I worked in contracting, we provided free specs for engineering firms but when the project bid,  (we were not always low-bid) we lost about 75% of the jobs that we specified.  When other contractors won the work that we designed, we were never asked by the architect or engineer about the qualifications of the low bidder, or substitutes they offered. They typically just accepted substitutes. At that time we stopped doing vendor specs which, from a business point of view, made no sense as it was unpaid work. To this day I do not understand why some contractors continue this practice.

In public bids, whoever wins the bid gets the job based on price alone. If there is any other arrangement between the vendor and the design firm to get a vendor the job, it is known as “collusion” which is illegal in most states.

There are a couple of problems we have found with vendor-based specifications. In most states, if the vendor who wrote the specs also bids the job they cannot have been paid for their input. Knowing that, the vendor’s input is minimal.

When the job goes to bid and someone other than the vendor is the low bidder, the engineering firm that had the vendor’s work on their drawings must determine whether to accept substitutes. The vendor, having lost the job, now has extraordinarily little interest in spending time reviewing substitutes.  They will usually just say, “oh no, that’s not equal”. Or they may just say nothing at all. It is a flawed process.

And who decides if the final install is done properly? The unpaid vendor reviewing the work of the people to whom he lost the job? Certainly, that will go well.


Most consultants have knowledge that goes way beyond the list on the internet.

Things like:

  • How it all works as a system
  • Whose equipment is reliable
  • Which manufacturers have good tech support and backup  
  • And the integration required to get the tech into an actual facility

The consultant takes a wish list from an owner and turns it into design criteria. They plan a budget early on to see if the budget assigned supports the vision.  If it does not, the consultant helps to adjust the vision, balancing the needs and wants to the money available. If you don’t follow this process and find out after bid that the money wasn’t there, the bid will get tossed.

During the bid phase, contractors may make site visits and questions arise. The consultant is involved in the entire project and can resolve issues that come up during bid and during construction.

And if the  consultants do not know something, they are paid to find out. Research is part of the work.


The consultant should be multi-discipline and therefore  able to take on all of the conflicting requirements for each system and come up with resolutions during design. Many things like to occupy the same spaces : Lights, Speakers, Stage Rigging, HVAC, AV, Screens, etc…… The consultant ensures that placement of specific items is coordinated to accommodate the technical systems and their requirements. 

Consultants also provide electrical, thermal, EMF, structural loading, and other information to the other designers on the team. The consultant must flesh out the systems and coordinate with all other design team members – architect, engineers, etc. The consultant makes assessments about ergonomic issues, operational issues, and discusses the owner’s specific requirements in light of their experience.

Professional consultants must take all that knowledge and put it in a form that can be bid by a contractor.

In public bids, the contractors that bid may or may not have all the skill sets required to fully implement the designed work. In these cases, it is important that consultants create specs and drawings that spell out the work in a way that requires the bidder to procure outside people with those qualifications.

This necessitates that the consultant set the parameters for what is to be used, where it goes, how it is to be installed, how it is to be set up, how it will be programmed, and how the owner will be trained on the equipment. The consultant also must review any substitutes a contractor may offer up, to determine if the change will compromise the design.

It’s kind of like teaching someone how to play an instrument by remote control. To do that, you have to know how to play the instrument in the first place. Some consultants allow manufacturers to do the design work for them. In other words, they are allowing salespeople to determine outcome, which seldom leads to a win for the owner.  

The best consultants take the time to research and even try out all of the technology they are going to use for their design. They do not leave the decisions to others who may have bottom-line as the defining factor.

Consultants take responsibility for the entire design and outcome. They are worth the investment if you get a good one.


Copyright 2021+ AVL DESIGNS INC.

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A Story of Audio … and Taxes

So, let’s talk about audio and taxes. It doesn’t seem like they go together, does it?  Hang in there with us and you will soon see what me mean.

We specify a variety of audio consoles for  theaters in, high schools, and colleges.  Without dispute, the single biggest mistakes we come across after these consoles have been in place for months is that there still is no content.  

No Content. That Is A Problem.

There are no templates. There are no libraries saved . (If you are drawing a blank on what those are we will explain.)  This scenario is all too familiar. Your typical digital console has an input channel and there are all sorts of  things you can do to it. You can turn gates on and off. You can turn compressors on and off. You can play with EQ’s. Yes, there is all kinds of nice stuff you can do with it. And that is the rub. What should you be DOING with it?


So, let’s get back to this “taxes” thing.   When you think about your console, you have a lot of different things you do with it in a year. 

You do theatrical productions.

You do lectures.

You do concerts.

You host lectures.

And every time you do one, you have two choices. You can have settings saved to start your event out with, or you can start from scratch again and again.

Save The File. Do It Now.

Now, here is the income tax analogy. Every year you have to calculate and pay your taxes, or the government will come after you. There are a number of online services you can use that will do the work for you. You just go to their app, type in all your  stuff, it then tells you that you owe a million dollars so that you can simply write a check and all is well. Or go to jail.

Or, there is another choice. If you know how to use Excel, you can build a complete tax calculating program yourself on an Excel spreadsheet.  

That probably would take a painfully long time but you could do it. You would just have to take all the formulas and all the required information and build your own tax filing program. Then every year you could do it again from scratch! Is that the best use of your time?  

Well, just like it is smarter to let an expert create a tax filing program for you to use, the console designers have built in ways to create and save settings  so that the technician does not have to construct it over and over again. 

You can save a show to the hard drive of the console and bring it up to be tweaked and reused again and again.  A template can be made to use for the next show, with custom adjustments made for that particular event, and saved for use again and again. 

With little effort, a new version of the event can be fashioned instead of starting from “square one.” When it comes to consoles in high school and college auditoriums, this is virtually what we see happening. The audio engineer creates a show that works well and never saves that content to the library or scene libraries. He doesn’t make a template to start with when it is time to design the next show, either.  Nothing is saved.  Absolutely, nothing!

It’s what I see people doing in all sorts of venues.  

What They Should Do.

Every venue  has various microphones all of which need specific  EQ and settings to use on a the sound  system in that particular  room.  For this  discussion let’s  talk headsets for theater.

Pick a channel, get the gain set, and Eq the mike to taste and to avoid feedback. Add compressors, gates etc….. to get the sound and dynamics you want on that mike.

Once you get  channel set up and sounding  good save it in a library file.

Set the file save so you are saving the gate, EQ, the compressor and all of these features to that particular channel library.  Now, if you had a dozen of these headsets and were going to be doing a theater production with them, you could go back and populate a bunch of channels by just pasting the library channel in. Every channel  would start out sounding exactly like the one you saved.

Now that may not seem like a big deal, but when you think about bringing a channel up from scratch, it’s  not as huge a deal in a studio environment, but in a live environment where you’ve got gain before feedback and room acoustics to deal with it is. You want to be sure any channel you make live is safe and sounding  at least Ok i.e. neutral.

Then you ( or someone less skilled than you) want to create a show and be sure that when you start out with each actor in your tech rehearsal, you’re not creating feedback and having problems start out with  by using a  preset for the headset.

There are some other things you have to think about. Make sure your belt pack gain structure is the same. It’s the same type of headset, all of that stuff, but you then can take a dozen people, throw them on stage at a tech rehearsal, and you will be able to turn all of their mikes on and off without any potential for sudden feedback or gross errors.

And then you  can work on tweaking their individual voice sounds.

So that’s the real purpose of a digital console is to take the skill set of somebody else and use it to bring up what you want to work on.

So let’s talk about some of the options you have for these kinds of things.

So what we’re going to do is switch from a headset to an SM 58, which is set up with no EQ it’s just flat at a 6” working distance. You can also save one with EQ for a 12” working distance.  You can also save it for “lips on mike” with appropriate  EQ and gain changes for each.

Then set up a chorus with AKG C414’s or whatever mike  you like, and do the same. 

These become starting points for various mike types and uses.

So as you create libraries, when you get ready to do an event, you can say, okay, I need these mikes for choir. So I’m going to bring up the,  AKG C414, put those into some channels.

And they’ve all been preset to be safe for what you’re trying to do.

So  the thing I would recommend, and this is for  anybody who has a digital console, is you need to find a way to rehearse scenarios with live sources, create presets for channel libraries, whole console templates, etc…..  

Define whatever types of events you may do repeatedly and create these preset scenes and  libraries and get them set up so that when you’re getting ready to put an event together, it’s not starting from scratch.

Kind of like doing your taxes. The easy way with a template someone  else made.


Copyright AVL Designs Inc. 2021+

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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.


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.)


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.


Copyright AVL DESIGNS INC 2020

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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.


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!

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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. 


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. 


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. 


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