Auditorium sound Reinforcement System speaker placement

The auditorium is "a place for listening". This definition implies that all aspects of space, as long as they are related to communication, should be given priority.
InSound Reinforcement systemBefore the invention, a large number of people gathered in the auditorium to listen to the speaker without sound amplification speech. The auditorium uses the geometric structure of the room and the sound treatment to provide a natural sound enhancement for the sound source.
The ancient Greeks even added a sound tube to the actors ' masks to cover more viewers. But even with these tools, it is not really effective to solve the problem of speaking to a large number of people-until people invented the sound reinforcement system.
　　 sound reinforcement systems are necessary for a minimum of four reasons:
1. Room size-The room is too large for the audience to hear the natural sound of the source in the distant seat.
2. The geometrical structure of the room-the geometry of the modern auditorium is not competent for the natural expansion of sound. The popular 180-degree fan room is at least 60 degrees wider than the coverage of untreated vocals. As long as the speaker turned a head, some viewers could not hear the content of the speech.
3. Ambient noise – The background noise generated by human, transportation, heating and air conditioning systems obscures the sound source and makes it impossible for some or all listeners to hear clearly.
4. Acoustic processing-The sound treatment required for natural sound amplification can be very expensive and does not apply to all musical styles.
When social activities require large numbers of people to stay in large spaces, sound reinforcement is necessary.
　　 an analogy
When lighting a room with lights, people use the right lamps to illuminate the light where they are needed. This is understandable to everyone. and sound system Designers are choosing and placingSpeakeris also true.
If you have good room acoustics, some of the major sound problems, such as poor effective gain and poor speech intelligibility, can be attributed directly to inappropriate speaker selection and position placement. The most common reason is that sound designers have to give up the preferred speaker type and placement for aesthetic reasons.
　　 Building and sound reinforcement
Architects often see loudspeakers as objects outside the building and are "appendages" that do not really belong to the whole. The School of architecture does not teach sound system design, nor does it need to be taught. They emphasize the visual effects of the site, placing a lot of attention on the geometry and visual flow of space.
This is their mode of thinking and the duty of their work. Large, conspicuous loudspeakers disrupt their overall concept of space.
When designing a room, the architect did not know the type and number of speakers needed, so it was impossible to integrate the speakers into the design. And even if they do, we'll see that their efforts to disguise and hide the speakers are likely to damage the performance of the loudspeaker.
For loudspeakers, to accomplish their mission, they must occupy some of the most visually important parts of the room. It's no wonder architects and sound system designers often collide.

　 three major variables
The sound System Designer's job is to make sure that everyone hears the sound of amplified sound. To achieve uniform coverage in the audience area, they have to deal with three major variables.
Includes:--speaker type--speaker position--Number of speakers
If the system designer gets the power to control these three variables, the work that comes out will be the best. If a customer or architect sets one or more of these, the System designer's workload is reduced, but the sound reproduction effect will be compromised.

　　 Speaker Position
The ideal position of the speaker is not achievable. The ideal location is where the sound source needs to be amplified.
Imagine a small troupe or classical orchestra performing in a small venue. The sound from each source can be heard without any amplification, and the spatial position of the other sources is accurate.
As the room size increases, the instrument may need a sound amplification. The orchestra has been using local amplification (localized amplification) for many years now, and today's "personal" sound systems are still on the market for small-scale applications – a modern reappearance of the "sound wall" technology adopted by the Grateful (Dead) band decades ago.
(The acoustic wall Wall of sound is a huge sound amplifying system that was specifically designed by audio designer Owsley Stanley for the live performance of the Grateful Dead Band in the 1970 's. )
The location of the sound source is the natural position in which it is emitted. This approach is unrealistic and inflexible in many applications, so we need a compromise approach. The preferred option is to place the speaker directly over the sound source that needs to be amplified, which takes advantage of the human hearing's inability to position the sound well on the vertical plane.
If the speakers are placed on the left or right side of the speaker, the listener will obviously feel that the sound is not from the speaker. If the loudspeaker is placed above the speaker, the listener's auditory system is blinded, and the voice is thought to have been sent from the speaker. The eye effectively pulls the pan low to correspond with the visual. The speaker on top also allows the sound to be projected into the back of the room without allowing the front-row audience to hear loud noises.
Given these aspects, it is reasonable to put the speakers directly above the stage.

　　 size vs Efficiency
The speakers must be large enough to control where the sound goes. The small speakers radiate sound in all directions.
As the loudspeaker size increases, its directivity increases. Directivity control is absolutely necessary in all audio systems, and the more control you need, the greater the speakers should be. That's the way it works.
Another reason to select large speakers is to consider low frequency efficiency. In many places of worship, it is hoped that the system can produce extremely high levels of sound pressure at very low frequencies.
This means that a large amount of air movement must be made, which in turn requires a larger piston surface area. Without large speakers, it is not possible to get high sound pressure levels at low frequencies in large spaces, and many speakers are often used to achieve this.
The lower the octave requires the more radiant surface area. If you want to replay the thunder of an Easter musical performance, or the bass pedal of an electronic organ, it is best to prepare a very strong low-frequency loudspeaker system. This must be a large system and should be placed in the room.

　　 Sound Problems
Many of the typical faults in sound systems, such as low clarity, opacity, and poor sound positioning, may be attributed to reflective sound. Most of these harmful reflections are caused by hiding and masking the speakers.
The reflection sound is an objective existence. We expect reflective sound, use reflective sound, and need reflective sound. But not all reflections are beneficial. Sound designers try to avoid two kinds of reflections, one from objects that are close to the speaker, and one from objects far away from the speaker.
The first reflex causes acoustic staining, and the second causes an echo, which reduces the clarity of the music and speech. Trying to disguise the speaker always produces early reflections that change the frequency response of the speaker. These include nets, enclosures, and holes that have been carefully designed to look more visually. In short, the actions that make the speaker more aesthetically pleasing can often make the sound worse.
A thoughtful design will allow the speaker to be masked and still have acceptable performance. Unlike light waves, if time is not aligned, sound waves may cancel each other out. But that is not entirely bad.
The sound System Designer uses phase length and phase-out interference to enable the loudspeaker array to achieve the desired coverage range. A good sound designer can understand the role of interference and know how to use it to improve the performance of the system.
Let's look at some ways to visually reduce the presence of a loudspeaker.
Cover--the screen always interferes with the sound. The only problem is "the degree of obstruction" and "whether it can be heard".
I've seen system designers pay a huge price to extend the sound system's frequency response to more than a few khz, but hide everything behind a hood that doesn't pass above the band.
But even without the hood, because of the air absorption, more than a few khz sound energy is likely to be communicated to each audience, so it is acceptable to use some fabric cover in front of the loudspeaker.
The fabric, of course, needs a frame. The frame is much more obstructed than the fabric it supports. The frame component should be made as small as possible, preferably not on the main channel of the system high frequency drive.
Cavity placement – The worst place to place the speaker is in a cavity. The loudspeaker itself is a carefully tuned resonant system. Its size, volume and openings are carefully selected to produce the desired response.
The essence of the cavity is the box in the box, which will bring a noticeable change in the response of the loudspeaker. Considering the energy expended in designing the loudspeaker, placing it in a random-sized cavity always destroys the designer's ideal response.
Mesh cover-do not paint the mesh, even on a very thin layer of cloth. The paint will clog the holes through the sound waves. If the screen color is incorrect, replace it.
Please keep two points in mind before choosing the desired mesh cloth. The mesh cloth should be acoustic penetrating and should conform to the fire safety regulations. Unfortunately, these guidelines will exclude most of your first choices. It is very easy to test the audible effect of the mesh cloth.
Simply listen to some music and vocals through a reliable speaker, then cover the speakers with a mesh cloth sample. What you hear is the test results. If the mesh cloth changes the sound, do not choose. You will find that the air is easy to pass through the fabric to produce very low sound attenuation and is a good choice for masking loudspeakers.
Easy Maintenance--it's necessary to fix the speakers sooner or later. Keep this in mind when assembling the hood, which should be removed as a unit or module panel.

　 back to the position .
These acoustic traps can be avoided by placing the speakers in free space, without any objects next to them. One notable exception is the ultra-low-frequency loudspeaker, which, due to its long wavelength, can be naturally amplified by the room boundary.
This arrangement enhances the sound of the subwoofer, but if applied to a medium-to-high-frequency loudspeaker, it can be very bad because the medium-high-frequency loudspeaker has a shorter wavelength and cannot be coupled well with walls, roofs, and other adjacent surfaces. A compromise is to have the engineer paint the speakers and mounting hardware, and the metal mesh cover is coated with a thin layer.
Most speaker manufacturers can provide a non-surface version of their products. The panel can be used on the surface of the box, but be aware that the adhesive will take off over time, causing the veneer to fall from the ceiling, causing danger.
In a fully functional room, the speaker is not the only add-on device. Other include ceiling fans, HVAC vents, luminaires, structural beams and support pillars. No one has any doubts about their existence, and no one really cares if they are visible.
We do not require architects to completely hide ceiling fans, or even more, require them to reduce the ceiling fan size. The same is true for speakers.

　 Find a pattern
I worked in the audio industry for a long time and found that there was a pattern in the public space to install the sound reinforcement system.
The first design is always visually acceptable but not good enough for sound. As the system is upgraded over time, the final system sounds great but the speakers are visually striking.
In an auditorium, the consideration of sound should ultimately be above visual considerations. Just as the headset is accepted for its sound advantage, so should the large, visible speakers.
The main component of the sound reinforcement system is the loudspeaker. Just as a tour guide would stand in a flat and open place in order to communicate with a group of people, the speaker in the sound enhancement system would be best if it could be seen.
This view helps shape the aesthetic views of architects and end-users. The "Formal obedience function" applies here. When determining the type and placement of sound systems in a venue, the sound quality should be taken into account when reproducing sounds.
It is natural to be able to see where the sound we hear is sent. The reason we have two ears is because we can locate sound in space.
It is almost impossible to achieve the best sound quality if the selection and placement of the speakers is only based on aesthetic considerations. In fact, if the most important function of "land for listening" is measured, many rooms are simply not standard enough to be used as a useless place.

Auditorium sound Reinforcement System speaker placement