acoustical design

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.

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Copyright AVLDesignsInc 2020

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

Part 2? Coming soon!

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Yamaha AFC

AVL Designs Inc. Featured on ProSoundWeb

NY-Based AVL Designs Inc. Deploys Yamaha AFC On Numerous Projects Over Several Years

Acoutical designers and engineers at Ciminelli Recital Hall  at Buffalo State University
Audio engineers working with performers in Ciminelli Recital Hall at Buffalo State.

Reprint from ProSoundWeb article April 23, 2020

Company principal/owner, Seth Waltz, reflects on the evolution and application of acoustic room conditioning technology on a range of projects.

Seth Waltz, a principal and owner of AVL Designs, a Penfield, NY-based firm specializing in A/V system design for performing arts, theater, worship, and several other applications, has worked closely with every version of Yamaha Active Field Control (AFC) acoustic room conditioning technology for more than 15 years.

He’s seen numerous changes in each of these applications, with traditionally high-end technologies being applied to smaller environments.

“Auditoriums with a few speakers and a microphone were once considered high-end A/V rooms,” he notes. “Now these same venues are being outfitted with million-dollar technology. The digital era has created a whole new mindset where a performing arts center, even at the school level, is looking for a higher level of everything: acoustics, sound quality, video quality and streaming. It’s all tied together.”

His first experience with AFC and its ability to configure and condition a space came in 2004 when he and his associate Geoff Nichols were invited by Yamaha to a system demo.

“We walked into what looked like a large office space with drop ceilings,” he explains. “A pianist backed by a string quartet performed for us with AFC applied to the room. If you closed your eyes, you would swear you were in a 500-seat theater. It sounded extremely natural. We got to play around with the system and we soon realized this is the future of room acoustics as far as having the ability to modify a facility as needed.”

AVL Designs Inc. first implemented the AFC system on a design project in 2005, turning a “plain Jane auditorium” into what sounded like a completely different sonic environment and drawing rave reviews from the project owner as well as the musicians who performed there.

Waltz points out that AFC technology has improved greatly over time, especially in terms of its processing and responsiveness. He’s also suggested new system developments such as an “orchestra shell”, allowing him to configure the stage as opposed to just the seating areas.

“With most of our jobs now, we’re simulating the performance of orchestra shells as well as covering the seating area and early reflections,” he says. “Now that the processors have become so powerful there’s no limit to what type of space AFC can fit. We don’t have to even think twice about metallic edging or other factors. It sounds so smooth that nobody seems to know it’s there.”

Waltz noted the only challenge to a successful AFC installation is a room with a high degree of mechanical noise, more common on projects that are updates to an existing space.

“You can’t have background noise or anything that creates echoes,” he said. “You won’t hear the nuances of the reverberation. Plus, the microphones pick up the noise and cycle it back through the system.”

Waltz looks forward to future versions of AFC incorporating new features and capabilities suited to a diverse range of applications. These include using the system as an effects device or controlling it via a mobile device. AFC4 can be controlled using the Yamaha ProVisionaire Control app on a PC or Windows tablet as well as ProVisionaire touch for iPad. These two software tools allow customers to create customer user interfaces to control various Yamaha equipment to simplify system operation for non-audio professionals.

Whatever changes are ahead for Active Field Control, Waltz is already confident in the technology’s ability to handle any project challenge. “Often at the tail end of a bid, someone changes the seating and suddenly the space is absorbing a sound we didn’t expect,” he concludes. “Or, something may happen during construction where you end up with different frequencies or there’s some other problem you wish you could do something about. AFC fills in the holes and helps compensate for these factors.

I tell clients, ‘I can give you one room that does one thing really well, or I can give you a room that does several different things well.’ Accomplishing this with physical construction alone is limiting, but AFC is extremely flexible and able to make one room do the job of many. It’s such a great tool.”

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Yamaha Pro Audio

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SUNY Cobleskill auditorium renovation #acoustics #audio #lighting #rigging #design

State University of New York at Cobleskill

AVL Designs Inc. recently completed a multi-faceted project at the State University of New York at Cobleskill.

The project consisted of a renovation of a lecture hall and a gymnasium field house. The lecture hall space is now being used for more multipurpose events including music, standup comedy, small theater presentations and video conferencing.

SUNY Cobleskill auditorium renovation #acoustics #audio #lighting #rigging #design

AVL Designs Inc. was contracted by the architect to provide acoustic design, audio system design, stage rigging, curtains, lighting and controls as well as video presentation capabilities for their new lecture hall.

Before and after photos show you the extent of the renovation, which was substantial.  In essence, it was a “full gut” of the space.

The gymnasium/field house had two issues. One was extremely live acoustics making the room unsuitable for many uses. Graduation and other events are performed in the gymnasium and the sound quality was quite poor. The primary reasons for this were twofold. One contributing factor was the acoustical condition of the room and the other was the sound system itself.

The old system suffered from poor intelligibility due to comb filtering. This was a result of a poor design not poor devices. The new design includes Danley loud speakers which are used for both bleachers and general court area audio. A fully distributed system over the court is used for events such as graduation. Acoustical treatment has been added throughout the gymnasium to reduce reverberation time and to minimize first reflection energy from the sound system.

Both spaces were ready for use early this year and have been well received by the clients and their guests.

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Copyright AVLDesignsInc 2021+

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Xaviers X20 on the Hudson

X20 Xaviars on the Hudson

When you are in the architectural acoustical design business, as we are, much of your work cannot be SEEN but is HEARD. You cannot photograph it. You just have to be there.Xaviers X20 on the Hudson

We  appreciated being part of the design team hired to make X20 Xaviars on the Hudson a dining experience worthy of the sumptuous food for which they are famous. From the amazing redo of an historic warehouse on the Hudson [Highland Associates, architects] to master chef Peter X. Kelly’s perfectly prepared cuisine, everything had to be “just-so.”

The X20 Xaviars On The Hudson Architectural Acoustical Design Project

Starting with an all glass exterior we knew it would be a challenge. Our acoustical skills were tasked  to create just the right atmosphere for the diners to enjoy. Not loud, not strident, but pleasant even when busy. (*which it always is …….)

It’s done in stealthy ways using materials that are almost invisible to the decor.


About The Master Chef & Owner Peter X. Kelly

Xaviar’s master chef and owner of X20 Xaviars, Peter X. Kelly:  Peter X. Kelly is known as “the man who brought sophisticated New American Cuisine to the Hudson Valley” Starting his restaurant career at the young age of 14 as a dish washer he moved on to a position as a banquet waiter while finishing high school.  Those two experiences were the humble beginnings of Peter learning the ins and outs of the hospitality business. At age 23 was given the opportunity to take over a country club restaurant where, unexpectedly, a disagreement with the chef [over, of all things, how to make beer batter] resulted in the chef leaving and Peter stepping into that role! There is much more to this fascinating story. Find out how he became a chef among champions. You can read the whole amazing story here=>  The Peter X. Kelly Story

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AVL’s part in this endeavor was to help acoustically design each room for the sound to be just as delightful as the stunning architecture and great food. Music and conversation were to be pleasant, not disruptive. Above all, nothing could be introduced that would interfere with the beautiful surroundings and great view. Our work had to be stealthy – invisible!

Mission accomplished! X20 Xaviars continues to be a top of the line dining experience – a perfect night on the town!

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Sound & Video Contractor’s Online Interview With Seth Waltz

Renovating a high school auditorium doesn’t sound like a big deal – unless it is the Baldwinsville [NY] High School Auditorium, that is! This high school hosts high-end performances of all types including concerts and Broadway-style shows.  AVL Designs Inc. was given the design-challenge to make that room acoustically adjust for any kind of performance situation, though the room itself had many limitations.

Mission accomplished! Baldwinsville’s auditorium is now capable of sounding like rooms of all kinds: lecture hall to concert hall – and this is just one of 22 completed venues with the same amazing results!

Listen to Sound & Video Contractor’s exciting podcast interview with AVL Designs Inc. President / Designer Seth Waltz to hear all about this amazing acoustical transformation: Baldwinsville High School Design Interview PART 1

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