Author: AVLAdmin

Auditoriums Being Renovated? The Most Important Thing To Consider

This advice is primarily for theater folks who work in school districts. Are your auditoriums being renovated? It will be helpful for you to be aware of the design and bid process that you are entering into before things get too far along.  

First, there will be an architect on board and probably some engineering firms, as well. If part of the scope of the project includes stage rigging or lighting or audio or video or any of the technical parts of the auditorium, who will design that work? This is a very important consideration.

There are two paths you could take.

  1. On one path, the architect hires a theater consultant for his team who stays with the job from get-go to the tail end, making sure everything is done properly.  That includes assuring that it is set up correctly and seeing to it that people are thoroughly trained on all the new equipment. The theater consultant is there, representing you the client, to make sure that everything goes the way you want it to.
  2. The alternate path that they could take does not include a consultant and, instead, you get “vendor specs.” Now vendor specs are an interesting breed…this is how it works:

You hire an architectural firm which also has an engineering firm working for them. Typically, the electrical engineer on the team gets tasked with doing audio, video, and theatrical lighting. Admittedly, there are some electrical engineers who actually know something about this work but there are many who don’t.

 

So what exactly is a “Vendor?”

The electrical engineers who don’t have those skills set get a “vendor” involved. A vendor is a third party who often does have know-how, but they also sell equipment. That makes their role a little odd. Vendors will not be paid for their time in specifying the project. In a public bid market, they may or may not even win the job. It’s less than a 50/50 chance, depending on how many bidders are participating. So, they spend time specifying something that may make them no money at all. There is not a lot of incentive in that to follow up later.

As the client you should understand that the way a vendor spec works is the vendor, who actually does have some skill set, provides some information to the engineer who then transfers that to his drawings and specifications. Now, in some cases it may be done fairly well. In some cases, it may be very, very basic.

We’ve seen bids produced as simple as one drawing for an entire audio system with no information of how to actually connect things, where speakers should be located, how they should be mounted and aimed, etc. Video projection often is left with no indication of where the inputs and outputs are.  We have seen theatrical lighting systems labeled as an “LED par fixture”, and that’s as far as the description goes.  The whole spec can be generic. The chances of you getting what you truly want can be slim.

The complaint I have with vendor specs is two-fold:

  1. It is wasting the time of someone who may never get paid for their participation which, as a consultant, I just object to. It is un-American.  As consultants we get paid for our involvement. And I think that is the way life should be. If, however, a vendor does get paid for their work, they are not supposed to bid that work.
  2. If a vendor specifies a system the next issue becomes “if they lost the bid, who reviews his submittals after bid and someone else wants to substitute products?”  

I had this happen on a job recently, we created a design for a school district where we did all of the acoustical work for all of their auditoriums, and they wanted high quality acoustics in their auditorium. So, we made them pretty reactive meaning that anything that happens in the room is very audible.

A different designer did the theatrical lighting. Our design included the stage shell.  We asked the engineer to use a specific light in the stage shell because we were concerned about noise over the orchestra.

So, we had our fixture specified for the part of the job we cared about, the rest of it was handled by the engineer. Now to his credit, he worked with a manufacturer’s representative (ie. Vendor) who gave him good information and he specified some really good fixtures for the rest of the lighting system. The problem came in when the project was bid and the low bidder substituted everything, including the shell fixtures.

We chose these lights for a reason.

The LED lighting that was in our original design had been carefully selected for two aspects: one was color quality, and the other was fan noise. The substitute that ultimately was accepted by the electrical engineer was very noisy. This happened because he didn’t know any better, He was going by cut sheets, which don’t refer to noise.

After the lighting fixtures were installed, we were contacted by the owner since we had designed the acoustics. They wanted to know why the lights were so noisy. It was because no one ever showed us the submittal on what was being substituted. The engineer was dealing with us as if we were a vendor and they don’t contact vendors on substitutes.

When we found out what they had done, we had to explain “the rules of the road.” The LED lights that they had accepted could indeed be run quietly only if they were willing to accept 60% light output. With those particular lights, that is the only way to get the fan noise low enough.

Vendors are pretty much in it to make the sale. This is a real-life example of a vendor that made an alternate selection – his product – as a substitute in the bid so that he could do just that – make a sale. They made that sale based on lumen output, color rendering index, and other factors. There was nothing in the spec from the engineer about noise, so he didn’t consider that factor.

As consultants, all of our specs for LED lighting have specific requirements for noise, and we never would have agreed to the particular substitute that was accepted on this job.  We put our 2 cents in, and the owner is now trying to figure out how they’re going to resolve the problem.

The room was designed acoustically so that you could hear nuances and harmonics. To protect these excellent room acoustics, the client will now have to accept low light output or unwanted noise in the room.

In this particular case, using vendor specs was kind of awkward. There were 2 vendors involved: the original one and the one for the substituted product. If the engineer had gone back to the original vendor’s rep asking what he thought of the substitute, he obviously wasn’t going to like it as it cuts him out of a sale.

So, both sides of that road are kind of rough. You’ve got people who haven’t been paid and lost the job. You have other people who are interested in getting paid and that happens if they make a sale. This is a scenario where lots of things can go wrong, and the client suffers.

Consultants work for YOU!

In our opinion if a customer, such as a school district, cares about the performance of all their systems in their auditorium, they need to have consultants on board that work for them, or work for the architect, and are not part of any sales organization. 

That was an example of a problem with lighting. In audio, we have seen even worse situations. We have seen people take a design from a vendor which might have been somewhat well done, but then allowed substitutions of everything, including where the speakers would be located.

“Which way does it go?”

Most recently we were in an auditorium where they substituted a speaker that was completely inappropriate. Then they decided that positioning a pair in the front of the auditorium in the corners, a pair halfway down the auditorium against the sidewalls and a pair in the rear corner of the auditorium firing forward would be a really good idea. Mind you, the particular loudspeaker they had specified has its own a wacky coverage pattern to begin with.

No, this was not surround sound. These speakers were not processed, independently tuned, delayed in any manner. They were all just running in unison.

It was like an audio “hall of mirrors”!

Charlie Chaplin in the hall of mirrors - movie The Circus
Charlie Chaplain “The Circus” (1928 film)

So, it was kind of like a “hall of mirrors” effect when you got into the room. It was just bad. So, we were called in to figure out why they were hearing all these echoes in the room and we had to give them the grim news.

The problem was multi-faceted. It was not just where all the speakers had been located but what they were and how they interacted with the room. By the time we got involved, they already owned it all, had accepted it and now were stuck with it.

A word to the wise in public bid situations is that someone must specify clearly what you, as the end user, want and that person should never be one who is also selling product. They should be someone knowledgeable whose sole interest is what you, the customer, wants and not what they would like to sell to you.

Consultants do have preferences. We might like a particular audio console or lighting console but if you like a different one, as an end-user, our job as a consultant is to get you what you want, not to get you what we want.

Please Get Qualified Consultants

So be sure to have the architect get qualified consultants on board.  Better architectural firms automatically do this because they know the benefit of having us on their team.  With some architectural firms, you will have to force the issue. (their engineers insist to them that they know what to do…..)

There have been times that we have kind of been thrown at some architects. They didn’t want to hire a consultant, but the end user was savvy enough to insist on it. They knew from experience that they did not want to leave this part of the project to the engineer, or to a vendor.

In defense of engineers, there are some who really do have more than a hobby-interest in audio, video and lighting and that is awesome – but they are rare.

 

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“HELP – I WORK IN THE CAFETERIA AND I’M GOING DEAF!”

Sound in cafeterias can be harsh. A primary reason for that is that cafeterias are difficult places to design acoustically but why is that?

Well, first, since surfaces must be easily cleaned, so some acoustical treatments cannot be used where they need to be placed. You can’t wash them. So, with that reality plus the sometimes-loud inhabitants of a cafeteria, there is the potential for a lot of noise. We get calls all the time with noise complaints about cafeterias. In most cases, design attempts were made to correct the problem, but the attempts were not well thought-out.

NRC RATING

Sound is absorbed by specific materials. Lab tests provide an idea of how well materials absorb sound know as NRC* ratings. (*noise reduction coefficient) NRC, however, does not tell the whole story on how well a product will perform in a given environment.  The way sound impacts an absorbing surface affects the way it performs. When sound strikes at a severe angle the absorption is reduced, and frequency response affected.

Additionally, where absorption is located is crucial in controlling apparent volume. Voices bouncing off parallel walls causes an effect known as “flutter echo.” This repetitive echo makes rooms sound harsh. You cannot control this by placing materials up at higher elevations in the room. It doesn’t work.

FREQUENCY BALANCE

The human ear is very sensitive to certain frequency ranges.  If a room has an improper frequency balance it can sound offensive no matter what reverberation level is actually present. 

LOUDNESS

There are two primary issues that make a cafeteria sound loud

  • Reverberation (Sound hanging around in the room over time.)
  • Frequency balance (The tone of the room: boomy, tinny etc.)

WHY CEILINGS DON’T FIX IT

As cafeteria ceilings are out of the reach of food, (that is except for the cafeterias with gravy-soaked drinking straw wrappers stuck to the ceilings.)  the ceiling is often looked to as the first line of defense.17

 

The ceiling can be used to control reverberation as well as to help balance the frequency response of the room. Some ceiling tiles, though, absorb the wrong frequency ranges in relation to the other materials that are present in the room. Better tiles have a more even spectral performance. But the ceiling alone really won’t fix the loudness. It is simply a first line of defense.

INVERSE SQUARE LAW

Looking at reverberation only, if you need to reduce the reverberation by an amount that most people would hear that requires a doubling of the amount of absorption. If you already did the ceiling, then where do you come up with that amount of surface area? It’s usually not possible.

When panels are placed on the walls, they can perceptually make the room much better, even though the overall reverb time may not shift dramatically.   Carefully integrated acoustic absorption on the walls, in the ear-height range on one or two walls, can do a lot depending on all other factors.

HAVE IT MODELED

Acoustic models can predict many factors including reverb, sound levels, flutter echoes and frequency balance. Controlling the noise in a cafeteria may seem simple, but it is still worth modeling.

Note: all three of the images are new cafeterias; acoustical designs by AVL Designs Inc.

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Making University of Buffalo’s Townsend Hall Quiet

Townsend Hall on the University of Buffalo campus in Buffalo NY is a turn of the century historic building, a wood and brick construction edifice. It has charm but is not the most inviting place when it comes to making renovations.

In a recent conversion, there was a need to add air conditioning and expanded office capabilities. Unfortunately, the only place to add the mechanical system was going to have to be in an attic above executive offices.

The design scope was simple in concept: keep the HVAC quiet and provide high levels of privacy office-to-office.  Execution was going to be a bit more challenging.  The HVAC unit is large – 22’ X 7’- and, as such, noisy. Isolation needed to be significant to keep the HVAC from creating low frequency noise and vibration throughout the upper floor.

Our first recommendation involved vibration isolators with concrete – the structure would not support the weight.

 

We opted for a spring-isolated drywall ceiling system below the attic with a high CAC ACT ceiling below. We were able to support thin multilayer flooring system in the attic, with the mechanical systems floated off the floor on new steel supports. Critical path silencers and double wall duct were used to keep breakout noise under control.

Office privacy was achieved with medium STC vibration isolated walls. Combined with the floating ceiling, this is what is known as a “room within a room” concept.

Throughout the construction process many field issues arose, as is often the case with old buildings. As layers of structure were exposed, challenges to the design required issuing details to solve what would be violations of the vibration isolation. The architectural project manager was very careful to let us know as changes occurred and we were able to say ahead of problems.

Some education was needed for the contractors as we found vibration contact violations were being introduced in the construction by various trades. These problems were caught and corrected. The various contractors did not fully understand the floating ceiling and that it must float. The ceiling’s small movement damps the low frequency noise. Spring clips touching metal, drywall touching building steel etc cannot be allowed. Once apprised of these issues, they quickly corrected the conditions and turned out a good final product.

At the end of the project, we received what in our industry is the best compliment. They said commissioning tests were not going to be required because it was so quiet that everyone was happy.

More about this project @ SWBR Architects => Townsend Hall Renovations

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Basketball arena at St Bonaventure U

St. Bonaventure University Field House

In 2019, AVL Designs Inc. started on a project to renovate the basketball arena sound systems of St. Bonaventure University. There was a bit of a delay on the project, which picked back up in 2021. The systems are now complete and being commissioned.

The purpose of the renovation was to improve sound intelligibility for game announcing plus other room uses such as graduation ceremonies and events containing musical content. Danley Sound Labs Inc. and Fulcrum Acoustic LLC. loudspeakers were chosen for their phase coherence, moderate cost, and high SPL capability.

St Bonaventure U field house

Combinations of SH 96i, SH 69i, CX1226, GH60, and DBH 218 subwoofers were selected to cover the various venue orientations. Power is provided by Danley DNA Amplifiers.    Midas M 32 consoles are utilized for the arena, as well as on-air video systems.  Sennheiser wireless systems are coupled with Neve Portico 5045 processors to provide high gain before feedback operation. QSC Core 500i processors are used to provide DSP and control processing.  

audio

Box suites are served by Ashly Audio Pema amplifiers with DSP, and JBL Control series ceiling speakers.

After a long C-19 delay, The Bonnies are finally getting their new system which will be used for their games in the very near future.

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Lakeshore Middle School auditorium

Lakeshore Middle School

The Lakeshore Middle school auditorium has not been updated in many years. All of the stage rigging is dead-hung due to challenging overhead conditions and lack of stage height. The district wanted to have some moving sets over the stage but the overall rigging was “creatively” installed and not up to safety standards.

AVL Designs Inc.’s first task was to design new stage rigging which would be up to current standards and with as many moving pipes as possible. AVL utilized ETC FlyPipes to accomplish this task. A self-climbing package hoist allowed us to provide a safe, moving solution.

The control of lighting and studio was in the balcony, which is not a great location for running a show, so a new control booth was included on the main floor to allow the audio and lighting crew to experience the show from the audience’s perspective.

New AV systems included main speakers with over and under balcony delays to fill shadowed areas. A new digital console, wireless microphones, projector and screen, and controls were also included.

Speakers by Danley

Wireless by Shure

Console by Soundcraft

Projector by Panasonic

Control by Crestron

Lighting was also in need of updates, as the existing Varilight dimming and control were failing. The decision was made to upgrade to all LED lighting. A new lighting console and control system by ETC was specified as well as LED fixtures from ETC and Phillips Showline.

*The completed project went on line in 2021 following some delays due to Covid.

 

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