Humor and Teaching

Wes and Dan were on top of their sound game when they came to teach and speak about sound technology at my church. They were not only clear and easy to understand but they brought humor and teaching style that made it easy for even inexperienced sound technicians able to understand what they were speaking about. Having worked with sound for just 2 years when they spoke at my church I am thankful for having had them come so I could further grasp and understand the complexities of running sound to its fullest extent.

Caleb Feese

Do You Hear What I Hear ?

“Blessed is the soundman when no one comments on the sound for surely when the sound stinketh, they will let you know.” from 4th Bubba, Chapter 414 of the Not Quite Ready For the Bible edition.

Okay, so maybe that is slightly irreverent, but it is certainly a fact of life for all soundmen. How often does someone come to you and tell you how they could not hear the (insert your instrument of choice) where they were sitting? If you say never, you are truly a great soundman and we all bow to you, or you are lying. I have had people come to me and complain about the sound when they were in a balcony that was clearly marked as a no-seating area, and thus no speakers were even focused in that area, and my favorite was the gentleman that complained that he was in the Lobby and the flute was not loud enough. Two points to consider here: 1. there were no speakers in the Lobby, 2. The Lobby doors were closed during the sound check and 3. There was no flute playing… anywhere…at all…maybe in his head? Alright you caught me, that was 3 points. Just checking to see who is awake.

These are extreme and humorous examples of what we all go through as practitioners of the Art of Sound Reproduction. But along with the absurd goes the truth, people will hear differently in different places in the room. Sometimes we can control this and sometimes we can’t.

So there is the potential problem. Is there a solution? Actually there are a number of solutions. The next few articles I post will give different approaches to solving this problem of perception. Here and now I give you the most important. WALK THE ROOM! Some of you know what I mean and to others, this may be a new concept. How can you understand what your congregation is hearing if you have only ever listened from the mix position? The truth is, unless your worship room has been expertly designed for sound reproduction, there is a great chance that different parts of the room sound different from others. This in fact is the norm. You are lucky and in the minority if your room has been optimized for sound. More typically it has been optimized for sight lines and aesthetics and usually by a committee! So WALK THE ROOM and become acquainted with how sound differs throughout the room. You will probably find that where the mix position is situated is either the best sound in the room (unlikely) or the worst (most likely) and that in making your mix decisions you may adversely affect the other sections of the room even though it improves at the mix position!

Now what do you do? Well, armed with this new information that you have gleaned from WALKING THE ROOM, we can explore different paths to fixing the problem areas. In the next few articles we will identify typical room problems and possible solutions for them. Hopefully if you fall into the category of Room By Committee, we will hit on your specific problem and give you some possibilities for correcting them. Happy walking!

Until next time, as we say in the music industry

Audio!

Dan Yeaney

7/15/2008

Selecting Loudspeaker Systems

When purchasing new loudspeakers, it is important to understand the total cost of ownership of the loudspeakers. Perhaps another way to look at this is to consider the total value the loudspeakers have to the congregation (the owners) and the users (the A/V ministry team) based upon the church’s requirements. The total value may include the loudspeaker’s performance abilities, aesthetic considerations as it relates to the sanctuary’s architecture, maintenance considerations, and their ability to integrate with future upgrades to the audio system. Selecting professional loudspeakers for your house of worship requires that a number of critical factors be considered in order to make an informed decision. After all, a professional loudspeaker system for your congregation is a capital investment, and, like any other capital expenditure, it should be carefully scrutinized before signing the check. Listeners will immediately point to the loudspeaker system when things do not sound “right.” After all, it is the most recognizable part of the audio system.

Why Professional Loudspeakers?

Because of the high demands placed upon them, professional loudspeakers are designed to offer greater performance and flexibility than loudspeakers designed for the consumer market. Professional loudspeakers often provide higher sound output; they can often handle more power than similar-sized consumer loudspeakers; and they are typically designed for semi-specific applications with specific performance characteristics. One of the main performance characteristic differences between professional and consumer loudspeakers is that professional loudspeakers are designed for more consistent sound throughout the coverage area.

Above all, reliability is often the biggest consideration for choosing professional loudspeakers. After all, the demands placed on them will likely far exceed the demands placed on loudspeakers designed for the consumer market. While many consumer loudspeakers will play loudly and for extended periods, they may not have the robust components or designs to handle the rigors of weekly services.

What Is the Selection Process?

The first step in your loudspeaker system purchase should be shopping for a qualified professional sound contractor and/or sound consultant. In addition to selling, installing and servicing your new loudspeaker system, the greater value that the sound contactor has at this point in your search is that they can help determine (sometimes with the assistance of a consultant) the best possible solution(s) for your congregation.

More often than not, the best way to find a reliable sound contracting professional is usually via word of mouth. Most religious congregations tend to be part of larger organizations (whether liturgical or social), and it is very likely that one of these groups will have had experience in hiring the services of a sound contractor in the past. It is also possible that a church member will have hired a sound contracting professional in the course of their own business endeavors. Also, there are those occasions where a member of the congregation itself may be an audio professional or knowledgeable in the field. A word-of-mouth referral will likely provide the piece of mind and credibility that the contractor you ultimately hire is capable of providing the needed services. A sound contractor and/or consultant can assess your building and loudspeaker system needs based upon your worship style and system performance goals. Remember that the sound contractor/consultant’s job is to ensure that you get the right product, equipment training, and/or acoustical treatments to achieve better sound in your facility. Loudspeakers are a long-term investment, so do not be afraid to ask any and every question you have before, during, and after the purchase and installation process.

What Are the Different Types of Loudspeaker Systems?

Every worship facility and service has its own unique characteristics that are determined in part by the worship style, as well as the physical environment of the worship setting. A sermon-based service will have different needs than a service that features a high-impact praise band. A service that is set in a large auditorium has different needs than a gathering in the fellowship hall. It is important to understand the different types of loudspeaker systems that could be used in your house of worship.

1. Point-and-Shoot System

The most common type of loudspeakers is often referred to as a point-and-shoot system and has the most recognizable form factor design. As the name suggests, these loudspeakers, when installed, are simply aimed toward the intended audience.

Depending on the desired coverage pattern (the area where the sound needs to be directed), point-and-shoot loudspeakers can be used individually or as part of a larger loudspeaker cluster. They are relatively easy to install, as many point-and-shoot loudspeakers include load-rated rigging or suspension points built into the loudspeaker cabinet. Depending on the components within the system, these loudspeakers can be used for simple speech reinforcement or with a high-impact praise band.

2. Line Arrays

For very large sanctuaries, line arrays have become a popular solution because of their clean appearance, excellent coverage patterns (by simply adding or removing cabinets or changing the box-to-box angling, line arrays can achieve varying degrees of vertical coverage), and their ability to provide consistent sound levels at a distance without volume levels dropping off. Most often recognized by their use in tour sound applications, line arrays are also available in smaller form factor designs for smaller or shallower sized rooms.

Some of the challenges, however, of using line arrays include height limitations, since vertical pattern coverage is dependent on being able to stack multiple cabinets on top of one another. In addition, a good line array can be expensive; thus, from a fiscal standpoint, it may not be the practical way to go.

Finally, if you choose a line array be sure that is what you get. Some products look like line arrays but do not necessarily have the loudspeaker drivers in the cabinets arranged to perform as a part of a line array system.

3. Column Loudspeakers

For highly reverberant rooms where speech intelligibility is a challenge, column loudspeakers are a great solution. Like line arrays, they are designed to focus their energy and minimized sound reflections in the space. They are easily recognizable by their narrow profiles, and their clean, simple form factor design makes them easy to integrate into most any décor.

4. Commercial Sound Loudspeakers

For ancillary areas (vestibule, cry rooms, fellowship hall, outdoor areas etc.), commercial sound loudspeakers are an excellent option. Designed to be discreet in appearance, commercial loudspeakers are available in a variety of sizes and performance configurations and can be flush mounted (installed into a ceiling or wall structure with only the grille exposed) or surface mounted (mounted to a wall or other surface) via a bracket. Many commercial loudspeakers also include transformers in their designs that allow them to be incorporated into 70-volt/100-volt audio distribution systems.

Running 70-volt/100-volt loudspeakers in your ancillary areas has several advantages.

First, fewer power amplifiers are required to drive multiple loudspeakers. Second, each loudspeaker’s volume level can be adjusted individually using the loudspeaker’s tap switch. These loudspeakers are easy to configure into systems that require specific volume or program material control over a certain area. Perhaps most importantly, using 70-volt/100-volt loudspeakers is a very efficient and cost-effective way of installing an audio system over a wide area.

5. Portable Loudspeakers

For temporary events or locations that do not typically require a permanent sound reinforcement solution, portable loudspeakers allow users to quickly set up an interim sound system. Available in a variety of sizes and performance capabilities, portable loudspeakers typically include such features as handles, pole mounts for “flying” the loudspeakers above the crowd. Many portable loudspeakers also include built-in power amplifiers for added ease of use.

In the end, one of the most important ideas to keep in mind when selecting a loudspeaker system is to remember that selecting a loudspeaker system is not the same as designing a sound system. While loudspeakers are the most recognizable pieces of your audio system, they are only a part of the entire sound system.

By Phil Sanchez

Phil Sanchez is a product manager with JBL Professional’s Commercial Sound group.

Our Thanks to JBL for their permission to use this article. If you have any questions regarding JBL loudpseakers please fell free to call us and let us help you with your needs. Thanks from Dan and Wes at Sound and Pixel.

Too Close For Comfort? screen selection

We have all heard the recent news of projector manufacturers boasting about their new 1080p capable projectors. With this newly created resolution is there an impact on some of the rules we have been using for screen selection? Perhaps we should reexamine such decisions as are we……
Too Close for Comfort? As time goes by for those of us in the audiovisual industry, we have all seen some very interesting and exciting technology come to the forefront. One such item that is setting the visual side of the equation on end is HDTV and 1080p capable projectors. Whether you are in the residential or commercial side of the audiovisual industry, you have no doubt heard the buzz that is being created by the introduction of projectors with a native resolution of 1920 x 1080. The advent of this chipset has pushed the proverbial resolution envelope once again. As that envelope is pushed, it creates a perfect opportunity for those of us in the screen business to reevaluate the rules we have in place for sizing a screen to a room.

If you recall not too many years ago, many in the industry decided that the rules that were used for sizing a screen needed to be evaluated due to the changes and advances that occurred in projection technology and the ever increasing need for audiences to not just look at a projection screen but be able to read or evaluate what was being presented on the screen. Much of this need was driven by the fact that software manufacturers were developing programs that allowed a presenter to put the highlighted text points in front of their audience, on a projection screen rather than on a piece of paper. For those of us in the PC world, we know this as the introduction of Microsoft’s PowerPoint software. When this occurred, we learned that the rules we had been using, when all we were doing was looking at video images, were outdated and inadequate for the task at hand. From the reevaluation, we determined that for a commercial venue we needed a screen height that was at least one sixth (1/6) the distance from where the screen will be placed and the most distant viewer for applications where we had to read the content and one fourth (1/4) if we were to inspect the image. To date, this has served us well. Now, let us take a look at whether or not the new 1080p formats will have an affect on this rule. Perhaps one of the biggest challenges we face with these new high resolution formats is making sure that the font size of the projected text is large enough for everyone in the audience to be able to read. It seems that every time I get a new monitor or computer it is higher resolution. When I turn it on for the first time, I am taken back as to how small the fonts on Windows have gotten. This is a result of the same font size being used by Windows but at the larger resolution. In other words, a 10 point text in one resolution might look like this, while the same 10 point text might look like this with a higher resolution. The reason this occurs is because the computer is using the same number of pixels to create the letters but since the pixels are smaller, and more of them, the same text is much smaller. For that reason, it is very critical that in any presentation we have control over the ability to change the font size in order to compensate for these discrepancies between resolutions.
Let us then look at this from a more mathematical standpoint. For purposes of this example, let us take a screen that is sized to 45″ x 80″. If we are using a projector that has a native resolution of 720 x 1280, we can easily multiply those two by each other and determine that we have 921,600 pixels being displayed on the screen. From that, we can determine that each pixel is 0.0625″ in height by 0.0625″ in width. By contrast, if our projector has a resolution of 1080 x 1920, keeping the screen size at 45″ x 80″, the pixel height now becomes 0.0417″ in height by 0.0417″ in width. As you can see, there is a fairly significant disparity between these two. Now let us look at how a computer presents text and fonts. How this occurs is worth an article in itself. So, for the purposes of this example, we will assume that for most Windows based software the 10 point Arial letter T is made up of a pixel structure that is 10 units in height. Armed with that information, w can now determine the percentage of difference between our Arial letter T in the two different resolutions. The smaller of the two resolutions will result in a height of 0.625″ for our character versus 0.417″ for the denser of the two resolutions. As you can see, with the new 1080 resolution our character is nearly 50% smaller.
To take the character height issue one step further, we learned from Volume III of “Angles of View” that in order for the human eye to recognize the smallest character being projected, that it must subtend at least 10 arc minutes. (An arc minute is a unit of angular measurement equal to one sixtieth of a degree or 60 arc seconds.) Through a long and involved set of calculations, this equates to the rule we have used to date that states we need at least ¼ inch in character height for every 7 feet of viewing distance. Considering that this rule is not impacted by the resolution of the display, it is still valid and should be followed. However, as we just learned, with a higher resolution display it is very likely that the font size that was used with a lesser resolution may not work with the higher resolution and is the reason why it is critical that we can change font size on our presentations.
Alright, so we know that we can potentially have a problem with the current rules and we need to make sure that our font sizes are large enough to ensure all of our audience members can read the text. However, what about seating distances and the screen size? When most of us see a movie at the local cineplex, we generally like to sit somewhere between half way back and in the middle of the screen. This, we feel, is the best seat in the house. No doubt this is in most cases just that. However, show up a little late to the screening of that “must see” new movie and you will find that the only seats left are those in the front row and perhaps are the seats that are to the far left or right of the screen. These are by most standards considered the worst seats in the house. Why is that the case? Well, as you would assume, the angles at which you are required to watch the movie, both horizontally and vertically, are sometimes uncomfortable. The human eye’s visual field of view is 135° High by 160° Wide. Although this is a very impressive range of vision, it is possible, as we know from the movies, to be too close for comfort. So, exactly when is this the case in a commercial boardroom or a residential home theater?
In Volume I of “Angles of View”, we learned that for most commercial applications that the closest we should sit to the screen is 1½ times the width of the screen and furthermore we learned that this row could be 2 screen widths across. So, does this still apply in the 1080p revolution? In order to answer this question, we need to see how this rule came into being. The calculations behind this recommendation were based on the off-axis angle at which a text character becomes more elliptical and less recognizable. The maximum angle at which we can acceptably view this character is 45º. Therefore, by drawing sight lines from a respective screen out from the left side of the screen to the right side of the audience and vice versa, we end up with an ever increasing cone which has an intersection point that is .5 widths out from the screen. At this point, only one person would be within the acceptable viewing position. Taking this out, further reveals our rule of 2 screen widths at 1½ times the width back from the screen. So as you can see, this rule has nothing to do with the resolution of the screen. It has only to do with the angle of which we are viewing the screen. Therefore, in the commercial world, we can make the assumption that our guidelines are still applicable.

As for the residential side of the equation, things become a bit stickier. If the room in which the screen is located is one that is multipurpose and has seating that may be offaxis at harsh angles, the rules we use for
the commercial world should be applied. However, if instead, we have a dedicated theater room with seating arranged much like the local cineplex, the rules change just a bit. If we apply the same logic that was used for the commercial boardroom application above, then we would say that a row that is 1 width back from the screen is able to be 1 width across. After all, the math works correctly.

However, let us think about this from a real world perspective. As an example let us look at the same 45″ x 80″ screen that was used above. Our normal rules for sizing a screen say that we should be no further back than 3x the height or 11.25 feet. In order to then determine the closest seating distance, we would say that it is equal to the width or 80″. Is this too close? According to our maximum off-axis viewing angle, no it is not, but what about the pixels? Will we see them seated this close? In order to answer this question, we need to look at the human visual system. If we are lucky enough to have 20/20 vision, that basically means that we can clearly distinguish one arc minute of contrasting information, from 20 feet away. Converting that to inches, tells us that in order for us to distinguish the contrast of that item, in this case the gap between two pixels, the pixel will need to be larger than 0.069 inches in height. Looking at our examples from above, we learned that our pixel is 0.0625 inches in height for the lesser of the two resolutions and 0.0417 inches in height for the greater of the two. As you can see from 20 feet back, neither one of them becomes an issue. However, once we move forward on the 1024 x 720 resolution we begin to have potential issues where as the 1080 x 1920 image does not cause problems until we get to somewhere around 12 feet rom the screen. So as you can see the scenario where we would be seated one screen height or 80 inches from the screen is way too close and we would likely be able to see the pixels. Since we have determined that at 12 feet is where we will potentially begin to see the pixels, let us use that information to determine the optimum seating area for the screen and ultimately provide us with a formula for determining the proper screen height. By taking the 12 feet and dividing our screen height of 45 inches, we have determined that the optimum viewing distance for a 1080p projected image is equal to 3 screen heights. So, our 1/3 rule that we have been using in the residential world is indeed still applicable and is not too close for comfort.
Blake Brubaker
bbrubaker@dalite.com

Sound and Pixel would like to thank our friends at Da-Lite for use of this article. If you have any questions about the Da-Lite line or need help with your screen and projection needs, please give us a call. We are here to help you.

Thanks

Dan

Dan@SoundandPixel.com

Let Your Light Shine! (but which one?)

 

Those of you that have been reading my articles, both on this site and other publications, for which I have written, know that I am a “punster”. Forgive me, we must be what we are, I will try not to punish you too much……sorry.

In this first in a series on the technology and artistry of concert and event lighting, I thought it would be a good idea to identify the different lights or “instruments” available to you. Therefore this article will be a simple lexicon or vocabulary list. We will add to this list in future articles, but this will get you started. I feel the same about lighting as I do about microphones, there is no such thing as a bad lighting fixture, only bad lighting technique. With some imagination and knowledge, even the most boring light source can be made to shine (oops) under the right circumstance and usage.

PARs or Parabolic Aluminum Reflectors. These are the basic workhorses of lighting design.  Their use is general coverage and they come in a variety of sizes and lamp designs. The PAR-64 is by far the most common with lamps available in M, a medium flood; N, a narrower focus, or even VNSP, very narrow spot; and more recently W, that’s right, a wide flood. PAR Cans as they are often called, are very dependable and a cost effective, dimmable light source.  There are additional sizes available from the PAR 16 through the 64. Sometimes these sizes may be “banked” together in groups of 4, 6 or 8 to produce audience lights or blinders, and cyclorama or up-lights. Furthermore, gels can be added to the PARs to add color to the design.

Fresnel  (pronounced fernel, the q is silent) Used more for studio and theatrical productions, it will rarely be seen in concert and event lighting due to its weight, size and general inefficiency when compared to a PAR lamp. A general wash lamp, don’t be too concerned with it unless you just happen to have a bunch lying around and little or no budget for new lighting. These are fast becoming a museum piece for concert lighting.

LEKO is named after the two gentlemen that developed this light, Ed Levy and Edward Kook. LEKO is actually a registered trademark of the Stand Company so the generic term ellipsoidal, short for ellipsoidal reflector spotlight, is often used. While somewhat expensive and fragile due to multiple lenses used, the ellipsoidal has its uses when a sharp edge or projected image is needed. They can add very defined areas of lighting, (spotlighting) and if the talent will consistently “hit their spot” these instruments can add much to a lighting design scheme.

Follow Spots as the words denote, are high intensity lights capable of throwing a very controlled pattern to the stage.  They follow the performer’s movements and usually highlight or lead the audience’s attention to where the designer or show producer wants them led. Somewhat out of fashion because of newer technologies, they never the less have a place in certain show or presentations. They do require an operator and therefore some type of communication (headset/mic) with the events producer which is often impractical or problematic (read: expensive).  

The most exciting innovation in concert lighting in recent years has been the introduction and development of automated lighting fixtures. Now in their fifth and even sixth generations of development these lights deserve their own article, and with that as a teaser, I invite you back for the next article in this series. We will look at automated fixtures and a few other special instruments to add to your lighting arsenal.

I hope this article has been illuminating for you. See you soon!

Dan Yeaney

They want you BACK!!

Our guys LOVED having you out. They really enjoyed their time with you and felt like you really equipped them. They want you BACK!! [Read more]

media

Please check out our article on screen selections in our video articles section http://soundandpixel.com/?cat=10