The family of horn speakers produced by Inter-M has been expanded with a modular product. The new loudspeaker consists of two independent parts: the SH-317 acoustic horn and the optional detachable DU-30T (or DU-40T) driver.
The acoustic horn and driver head are connected using a unified threaded connection. This makes it possible to simply replace modules when selecting the power of a loudspeaker, its maintenance or repair.
The use of the modular principle helps to achieve higher technical characteristics of horn loudspeakers, and the ability to independently connect individual modules to each other allows the user to assemble a loudspeaker with the necessary technical characteristics.
The loudspeaker is characterized by a more uniform frequency response, high sound pressure, clarity of speech reproduction, and resistance to extreme external conditions. It is advisable to use it for sounding stadiums, areas of commercial centers, parks, parking lots, construction sites, factory floors, and warehouses.
Purpose
A modular all-weather loudspeaker consisting of a horn device SH-317 and a driver head DU-30T (DU-40T) is designed for transmitting voice messages in broadcast sound systems with voltages up to 100 V indoors and in open spaces.
Expected delivery time: to order
Design
The loudspeaker consists of an acoustic horn and a driver head. The horn and head are manufactured as independent, complementary components, connected to each other using a 1-3/8” OD 18 TPI parallel thread. This connection is universal and allows the joining of modules of different types.
- 1 - magnetic system
- 2 - acoustic membrane
- 3 - horn device
- 4 - threaded connection of modules
Rice. 1. Sectional diagram of a modular loudspeaker
The supplied driver heads are designed for input power of 30 W (DU-30T) and 40 W (DU-40T). They have the same geometric dimensions. The mechanical strength of the individual head is achieved through the use of a silumin flange and a protective plastic cover with a wall thickness of 3 mm. The acoustic output hole of the module is equipped with a protective metal mesh.
Rice. 2. Driver head DU-40T (DU-30T)
Rice. 3. View of the driver head without the back cover
Inside the head there is a transformer and an electroacoustic emitter. The latter includes a special dome-shaped membrane made of fiberglass with a corrugated suspension and a voice coil placed in a magnetic system containing high-quality ferrite.
Rice. 4. Magnetic system DU-40T
Rice. 5. Sound membrane driver head
The input impedance of the electroacoustic emitter corresponds to 8 Ohms. To match the 100 V transmission line, a broadband transformer is used, located inside the protective cover of the module.
Rice. 6. Matching transformer in DU-40T housing
Thanks to the transformer, both high-resistance connection of DU-30T/40T into the line at full or half power, and low-resistance connection with a resistance of 8 Ohms at full power is realized.
The speaker input wires are color coded.
The SH-317 horn module serves as an “acoustic transformer” to match the acoustic impedances of the dense radiating membrane and the less dense air environment, as well as to form the loudspeaker radiation pattern.
Rice. 7. Horn module SH-317
The module consists of a plastic horn and a silumin flange with threads for attaching the SH-317 to the driver head. A steel swivel bracket is installed on the flange, which serves to mount the loudspeaker and orient it in space.
Rice. 8. View of SH-317 from the threaded connection side
In order to effectively distribute acoustic energy in space, the rectangular aperture of the horn provides a wider radiation angle in the horizontal plane than in the vertical plane.
The modular loudspeaker allows you to effectively reproduce signals with the lower limit of the frequency range from 300 Hz, which ensures the accuracy of speech signal transmission, naturalness and recognition of the sound of speech.
The loudspeaker develops a high sound pressure level, including due to the concentration of sound energy in a relatively narrow radiation angle. Its sensitivity corresponds to 110 dB, which exceeds that of the HS series speakers. At a nominal power of 30 W, the SH-317 horn with the DU-30T module creates 124.7 dB at a distance of 1 m, and with the DU-40T module - 126 dB. These levels significantly exceed all possible household and industrial noise. Modular loudspeakers should be placed taking into account the possibility of dangerous discomfort for people nearby, since the pain threshold of human auditory perception is 120 dB.
The back cover and horn of the loudspeaker are made of ABS plastic, which is characterized by increased impact resistance, durability, resistance to high and low temperatures, moisture, alkalis and acids, and direct solar radiation. The outer metal parts of the product are coated with powder paint followed by thermal treatment. Sealing materials are placed at the junctions of module elements.
The principle of operation of a horn emitter - section Education, Basic principles of the design of concert complexes. Mixing consoles. Equalizers and their applications. Connecting Cables and Connectors The Roughest Explanation of the Operating Principle of a Horn Emitter Can Be Made...
The roughest explanation of the principle of operation of a horn emitter can be done as follows. If you want to be heard from a great distance, then you must turn in the direction from which you can be heard and cup your hands near your mouth. In this case, your phrase in the forward direction will be heard louder than in all others, which is explained by the direction of the sound waves you create.
Without a horn, the energy of the sound waves from the sound source is distributed evenly in all directions, so the volume of the sound in any of these directions is the same.
A horn focuses the energy of sound waves from a source within a certain angle, so the volume of sound in the region of space limited by this angle is higher than in all other directions.
Human hearing has maximum sensitivity in the audio frequency range of the vocal range. The average frequency of this region is approximately 1000 Hz. In a four-band sound reproduction system, the value of this frequency lies on the border between the mid-low and mid-high frequency bands, so any inaccuracy in the tuning of these two frequency channels is very noticeable to the ear and sharply worsens the sound of the entire sound reproduction system. In order to completely eliminate the possibility of inconsistency in the sounds of frequency channels of a multi-band sound reproduction system in this critical area, special acoustic systems are used that reproduce an extended range of mid frequencies. The basis of such an acoustic system is a special mid-frequency dynamic head, which has a slightly smaller diameter than a regular one - about 4-6 inches. This head is installed in a resonator box of a conventional design, but is equipped with a special mid-frequency horn. Thanks to this design, this speaker system combines the advantages of conventional and horn systems, and the upper limit of the mid-frequency band rises to 3 KHz.
The use of dynamic drivers with a titanium diaphragm of a similar design in acoustic systems made it possible to expand the range of the mid-frequency band to the upper limit of the audible range. Such broadband mid-frequency speaker systems make it possible to exclude the high-frequency channel from the multi-band sound reproduction system, but since the power of these systems is low, powerful professional sound reproduction systems still use conventional high-frequency speaker systems to reproduce high frequencies.
Hearing sensitivity in the low-frequency region is exactly as low as it is high in the mid-frequency region. For this reason, very high power is required to achieve a tight, well-felt bass sound. This feature of low-frequency perception is very well illustrated by the human hearing sensitivity curves taken by Fletcher and Munson, which can be found in any good acoustics textbook.
End of work -
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Basic principles of organizing concert complexes. Mixing consoles. Equalizers and their applications. Connection cables and connectors
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All topics in this section:
What is a concert complex
A concert complex is a set of sound systems designed to provide sound in rooms during concert performances. The concert complex includes devices
Concert complexes of medium complexity
With simple systems, everything seems to be clear. Let's now look at a more complex device, for example, one of the concert complexes that are used for scoring clubs, discos or small
Mixing consoles
A mixing console is a device designed to collect electrical signals from all systems of a concert complex - microphones, musical instruments, sound effects and
Sensitivity
This function is sometimes called "input level" or "gain". The sensitivity regulator selects the required gain of the input channel of the mixing console in the range from the output level
Channel equalizer
A channel equalizer is a section of the input channel of a mixing console, designed to adjust the amplitude-frequency response of the channel. The regulators of this section m
Multi-band tone controls
Multiband tone controls, unlike parametric equalizers, do not allow you to change the value of the frequency at which the signal amplitude is adjusted. They only allow you to raise or
Quasi-parametric equalizer
This type of equalizer is a simplified version of the parametric equalizer, from which it differs in the absence of a bandwidth control. Full parametric equalization
Sensitivity switch
The sensitivity switch of the input channel of the mixing console is designed to set the sensitivity of this channel in accordance with the level of the output signal of the source connected to it,
Grouping
Grouping is the grouping of input channels on a mixing console into groups or subgroups.
Additional outputs
The system of additional outputs of the mixing console is designed to output a signal from any of its input channels from the console. Through additional outputs these signals, bypassing the main output of the mixing console
Group of controlled additional outputs
The output level of the controlled auxiliary outputs of the mixing console depends on the position of the input channel level controls. By changing the position of the level controls, you can control the balance
Rear panel of the mixing console
On the rear panel of the mixing console there are usually plug connections for connecting the input and output circuits of the console.
Each input channel on the rear panel of the console has at least
Graphic equalizer
Graphic equalizer is a multi-band corrector of the amplitude-frequency characteristics of electrical audio signals. The boundaries of the full frequency range in which it operates
Parametric equalizer
The operation of this type of equalizer has already been partially described when describing the principle of operation of a quasi-parametric equalizer for the input channels of mixing consoles. To what has been said it remains to add that
Spectrum Analyzer Applications
As you know, the amplitude-frequency response of a room intended for sound recording must be linear. It should not contain peaks and troughs that could affect the result.
Equalizer settings
The main equalizer of the sound reproduction system is the link between the sound of the sound reproduction system and the sound of the room. Its main function is room sound correction
Practical methods for correcting the amplitude-frequency response of an indoor sound reproduction system
Place the monitoring microphone somewhere in the middle of the room, pointing it towards the stage. Then connect it to one of the channels of the mixing console, set the line x
When setting the main equalizer, place the control microphone slightly away from the axis of symmetry of the hall
The sound characteristics of the main sound reproduction system, taking into account the influence of the room, can be adjusted using a control phonogram. As such a phonogram you can use
Rules to keep in mind when setting up equalizers
1) Make sure the equalizer is turned on and bypass is turned off.
Incorrectly folding jumper cables is bound to cause problems sooner or later. According to Murphy's laws, a poorly folded roll at the most inopportune time and at the most inopportune
Laying a multi-wire connecting cable
A multi-wire connecting cable or braid is used to connect external sources and signal receivers with the input and output circuits of the mixing console. The condition of this cable depends
Balanced and unbalanced cables
An unbalanced insulated cable is an ordinary insulated wire placed in a braided shield, also covered with insulation.
Purpose of a symmetrical connection
The main reason why a balanced connection is used is that a balanced line has higher noise immunity than an unbalanced line. Signal amplification, proi
International standards
For three-pin Cannon connectors of the XLR\AXR type, an international standard has been adopted regarding the purpose and numbering of their pins. If the connector is intended for symmetrical connection, then
Rules for handling connecting cables
1) All connections in the concert complex used to transmit sound signals must be symmetrical. An exception can be made only for those circuits whose signals have a high voltage
Crossover
A crossover is a device that divides the input signal spectrum into several frequency ranges. This division corresponds to the frequency bands of acoustic sound reproduction systems. Acoustic
Microphones
Modern microphones well accept all sound components that are necessary to obtain high-quality sound. But at the same time, they also well accept all sound components that are
All these qualities are possessed by most of the dynamic microphones, which do not require additional power sources and have cardioid or supercardioid directional characteristics.
Vocal microphones
When conducting concerts, it is very difficult not to come across a type of microphone such as the Shure SM 58. This microphone, reminiscent in its external shape of ice cream in a waffle cup, represents...
Microphones designed for scoring drum kits
When scoring a drum kit, it is very important to choose microphones for the bass and lead drums, because the sound of these drums determines the character and coherence of the work of the entire rhythm section.
Good
In order to accurately convey the sound of a piano, you need to use a large number of microphones, positioning them so that the captured sound most fully corresponds to its purpose in music.
Receiving the sound of brass and saxophone
The sound of brass instruments can be captured using a regular vocal microphone placed directly
Receiving the sound of a flute
Most flutists prefer to use a regular vocal microphone to receive the sound of the flute.
Radio microphones
Radio microphones have a number of positive properties. For example, they do not require a connecting cable, which reduces interference levels. However, they also have peculiar disadvantages.
Matching devices
Direct connection matching devices are designed to match the output and input of two connected devices. Most often, the matching parameters are the input and output resistance of the connection
By simultaneously turning on multiple delay lines, you can create extraordinary volume of sound.
Some tape reverb models have a special input for connecting a remote control pedal. This pedal is designed to stop the movement of the reverb strip during
Tape reverb device
A typical example of a tape reverb is the model of the Japanese company Roland RE - 201. This model can be found quite often, so we will give a fragment from the technical description for this reverb
Rules for working with a digitally controlled digital delay line
The D 1500 digital delay line has 16 banks for storing data - from 0 to 9 and from A to F. Before working with this delay line, you must enter the input and output level controls
Reverberation
The effect of artificial reverb has a very significant difference from the effect produced by a delay line, because reverberation is the sum of a large number of delayed decays
Spring reverb
Spring reverbs are still used in various studios today. Most of them were produced by AKG and Roland, but they were also produced by other companies. Now spring reverbs you
Digital reverb
Nowadays, a wide variety of digital reverb models are produced. They have a wide range of different capabilities, have many specialized sound effects programs,
Digital reverbs with analog control
One of the first analog-controlled digital reverbs was the Yamaha R 1000, which only had four reverb programs. However, it was very convenient to use, which
Special digital reverbs
At the time of its introduction, the Alises Midiverb digital reverb was the cheapest digital reverb that had multi-bank hardware programming. This reverb was produced in a small
Sound effects obtained by using a delay line
Audio delay can create several different audio effects.
Delay the signal for a period of time from 1 to 16 milliseconds, produced with a small modulation depth
Reverb sound effects
Reverberation sound effects programs typically reflect conditions in which similar reverberation occurs. For example, “small room”, “large hall”, “soft sheet”, etc. Nevertheless,
Compensation of signal delay in a concert complex
The speed at which sound waves travel in air is approximately 330 m/sec. Therefore, when placing additional sounding acoustic systems in the middle part of a large hall
Simple rules to make working with sound effects easier
1. Before starting work, check that the inputs and outputs of audio processing devices are correctly connected to the additional outputs and inputs of the mixing console. Make sure all audio processing devices are
Compressors and limiters
First, some technical definitions.
A compressor is an amplifier with a variable transmission ratio, the value of which decreases with increasing amplitude of the input signal.
Application of compressors and limiters
Compressors and limiters can be used both to process the input signals of a mixing console and to process its various output signals. The composition of the mobile concert complex usually includes
Setting the Noise Limiter
One of the most common applications of noise limiters is in processing the sound of percussion instruments. The noise limiter is connected to the channel of the selected instrument, for example, through connectors
External control input
Many models of noise limiters have an external control input. This input is designed to control the operation of the noise limiter using external audio signals.
Control and measuring devices
The most common measuring devices for concert complexes are all kinds of level meters. Most of these meters are designed to control and set relative
Amplifiers
Of all the electronic systems of the concert complex, the maximum load falls on the power amplifier system, the main purpose of which is to convert electrical voltages
Turning power amplifiers on and off. Power amplifiers are always the last to be turned on and the first to be turned off.
When turning on the power to the power amplifiers, you must adhere to the following order: 1. Make sure that all power amplifiers of the audio system are turned off and the volume controls are turned off.
The procedure for eliminating simple faults in power amplifiers
1) Turn off the amplifier and disconnect it from the power supply. Do not touch any parts when the amplifier is turned on, as power supply of electrical circuits and power amplifier blocks is high
Maximum amplification power
In order for an amplifier to produce amplification with a minimum amount of distortion, it must have the largest possible output signal power reserve. This power reserve is usually limited to
Amplifier power and load resistance
The ability of an amplifier to create a signal of a certain power is characterized by the amount of current that the amplifier can create in the load connected to it. In order not to get attached to numbers
Crossovers
A crossover is designed to divide the full spectrum of an audio signal into several frequency bands in a multi-band sound reproduction system.
Multi-band sound reproduction system
Passive crossovers
A passive crossover is a set of passive crossover filters whose crossover frequencies are fixedly matched to each other. Most often, passive crossovers are built inside a lot
Advantages created by the use of crossovers
All acoustic systems of a multi-band sound reproduction system are specialized to one degree or another. They reproduce some frequencies well and reproduce much worse or not at all
Cut-off frequency and slope
When setting up a crossover, it is necessary to take into account that the cutoff frequency of any of its bands is not a cutoff in the exact meaning of the word, but only some extreme frequency at which crossover begins.
Sometimes special horn low-frequency acoustic systems are used to reproduce the lowest frequencies of sound signals. The length of these horns can exceed 2.5 meters. In such a loudspeaker
Sound reproduction system control processors
Control processors for sound reproduction systems are quite complex devices, representing a combination of various crossover systems, equalizers, limiters, delay lines and devices.
Design and principle of operation of dynamic loudspeaker heads
Regardless of the type of driver design, all drivers operate on the same principle. All dynamic heads have a fixed magnet in their design,
The process of burning out the dynamic head coils
The dynamic head coils are wound from thin wire coated with varnish insulation. From prolonged heating, this insulation gradually becomes brittle, crumbles and burns. Because of uh
Bass Horn Speaker Systems
The horns of bass speaker systems are impressive in size. For example, because the length of the sound wave at a frequency of 60 Hz is 5.5 meters, the length of the horn that can influence the direction of this
Multi-way speaker systems
Recently, multi-band acoustic systems have become increasingly used in the practice of operating concert complexes. These systems can reproduce the full or almost full range of frequencies.
If the system can be installed and connected in only one way, it is almost impossible to make a mistake when assembling it
The signal connection in most multi-way speaker systems is made using unbalanced multi-pin connectors, which eliminates the possibility of incorrect connection.
Phasing of dynamic heads of acoustic systems
The dynamic heads in all acoustic systems of the sound reproduction system must be turned on in phase with respect to each other, i.e. the positive terminals of the dynamic heads must be connected
Relationship between electrical power of loudspeaker systems and sound pressure level
The volume of sound emitted by a speaker system is characterized by the sound pressure level, and not by the amount of electrical power of the speaker system.
In order to be able to compare
In the simplest case, a high-power acoustic reproduction system can be composed of similar multi-band acoustic systems, each of which has dynamically balanced
Dependence of sound pressure level of a sound reproduction system on distance
When moving away from the sound source, the sound pressure created by it decreases by 4 times, which corresponds to a decrease in the sound pressure level by 6 dB.
That. sound reproduction system
Monitor systems
The monitor system is the supporting sound reproducing system of the concert complex.
This system is designed to create additional sound in some part of the sounded room.
Inclined monitor speaker systems
Inclined, oblique-shaped monitor speakers are located at the front of the stage opposite the performers whose sound they reproduce. These speakers should
Communication between the main and monitor sound reproduction systems
All possible details of the relationship between the main and monitor systems are discussed in the chapter concerning the layout and assembly of the concert complex. To find out the basic principle of this mutual
Independent monitoring system
The central part of an independent monitoring system is the monitor mixing console. This mixing console is located in close proximity to the main mixing console and is connected to
Monitor system sound mixing
Mixing sound from a monitor system is very different from mixing sound in a room. When mixing sound in the hall, it is necessary to build only one balance, and the monitor system may require up to 16
When moving large weights, try to make the most efficient use of their inertia
When unloading speaker systems from a truck, they should be lifted by hand with the front panel facing down. To prevent a heavy box from slipping out of your hands, it must be supported from below with your fingers. This is pr
System assembly
When assembling the system, you will make fewer mistakes and spend less time if you adhere to a certain sequence of its assembly. For example, assembling a concert complex is better
Procedure for handling damaged and spare connecting cables
To hold a combined concert with the participation of several groups, it is necessary to prepare in advance, taking into account the specifics of the lineups participating in the concert. However, it will be easier to work with different groups
If all microphones and junction box input jacks are labeled, connecting instruments takes less time and attention
To avoid confusion that may arise when you are forced to use the inputs of the stage distribution box inappropriately, it is useful to create a table of correspondence between the numbers of input channels and
Microchannel mixing console
It is extremely difficult to flexibly control a band's sound using an 8-channel mixing console. It can be used successfully if the output signals of some instruments are previously
Ti-channel mixing console
The 12-channel mixing console allows you to more precisely control the drum sound, because... the working space occupied by a drum kit on such a console can be larger than on an 8-channel microphone
Ti-channel mixing console
The 20-channel mixing console provides the widest possibilities for building the sound of a small group, because... the number of its channels exceeds the number of individual instruments in the group. Will distribute
Grouping rules
A minimum of 4 group channels are required to control the monophonic balance of groups of instruments. To carry out the simplest stereo mixing, it is necessary to distribute pairs of
Assembly procedure for the concert complex
In principle, there is no strictly defined order for assembling the concert complex. The only assembly principle that should not be violated is the following. No need to unpack and install additional
Final tuning of the sound of the concert complex
First of all, the final adjustment of the sound of the concert complex should in no case develop into a rehearsal. The purpose of this important operation is to obtain the final sound
Adjusting the sound of percussion instruments
Having placed the microphones of the drum kit in accordance with the intended scheme for obtaining its sound, listen to the signals of each of them separately. Select the required channel sensitivity value,
Setting the Bass Guitar Sound
Before you begin adjusting the sound of the bass guitar channel, you must set the bass guitar channel level control to the position corresponding to 0 dB, and set the bass guitar channel sensitivity control to
Adjusting the Sound of Electronic Keyboards
The native sound of electronic keyboard instruments is designed to be directly connected to a sound reproduction system. However, connecting them directly is not as simple as m
The power supply phase of all electronic devices installed on stage must match the power supply phase of the concert complex equipment
Setting up the channels of keyboard instruments must be done at the maximum level of their output signal, because in this case you will be guaranteed against accidental overload of the mixer input channels
Adjusting the sound of an electric guitar
If the level of noise in the electric guitar channel is not too high, then adjusting its sound is quite simple. Select the channel sensitivity so that its signal is equally strong
Adjusting the Vocal Sound
The correct sound settings of the vocal channels largely determine the sound quality of the entire balance of the sound reproduction system. Vocals should be heard extremely clearly, loudly and cleanly, and be in perfect
Setting up audio processing device channels
Before you begin, make sure that all audio processing devices you will be using are working properly. Check the connections of their outputs and inputs. Jack connectors that
Power supply for the concert complex
The power supply phases of all devices and systems of the concert complex must match. The neutral power supply wires of all devices must be connected to the neutral phase of the power supply network. Not at all
Creating Sound Balance
Once all the equipment is set up and the performers are on stage and ready to play, you can begin mixing the sound.
However, in order to carry out this reduction, it is necessary
The relationship between vocals and music
The ratio in which vocals should be present in the overall balance of the work is determined by the function it performs. For example, in simple songs, the vocals should somewhat dominate the music. Ste
Rhythm section balance
The sound of the rhythm section should be smooth and tight. To achieve maximum richness in the sound of the bass drum, you need to make sure that it does not hum or sound too dull. If its sound
Checking the balance quality
With prolonged, painstaking listening to the sounds of individual instruments, attention becomes tired, and the ear gradually loses the ability to reliably assess the balance of the overall sound. Therefore it is necessary to
It’s a good idea to record all concerts with your participation on magnetic tape. Listening to these recordings, you can find many common mistakes that are repeated every concert. Having analyzed
Basic principles of mixing the sound of concerts of independent performers
A sound engineer performing sound mixing at a concert of an independent performer must take into account the specific distribution of the performance load in such a concert. An independent performer is not
Recommendations for mixing sound at a concert
1. when adjusting the sound at a concert, listen carefully to the sound and feel free to make the necessary retuning 2. while pre-setting the balance at the very beginning of the concert, the floor
Insufficient sound volume in the monitor system
Low sound volume from a monitor system is a very serious problem. In the process of work, all sound engineers will inevitably encounter it sooner or later, and sometimes they have to fight with it.
Drum monitor sound volume is insufficient
The drum monitor volume is rarely loud enough. It's very difficult to get a drummer to get into balance with his own monitor system, because that's what the monitor system does.
A special problem for drums
Do you know what words are particularly unpleasant for a sound engineer to hear? No, it's not "no money." It's much more unpleasant to know that the drummer is singing. These words terrify even the most steadfast sound engineers.
Psychoacoustic effect of perception of sound volume of a monitor system
In the process of adjusting the sound of a monitor system, as well as during long musical rehearsals, the auditory attention of people on stage becomes tired, so a constant increase in volume is required.
Troubleshooting technical problems
When the power amplifier's mains fuse blows, all of its electrical units are completely de-energized. The output signal disappears completely, the power indicator does not light up, and the fans turn off.
Reconfiguring equipment for the next concert
If the equipment has retained its settings from previous concerts, setting it up for a new concert is not difficult. In such cases, the sound of the sound reproduction systems is usually
Accelerated sound setup
It is incredibly difficult to immediately adjust the sound of a completely untuned system, especially if you were seated at the console 15 minutes before the start of the performance. The hall is full of noisy people listening
Simple rules for dealing with unexpected situations
- no matter what happens, try to remain calm. Determine the reason, think over a course of action and act boldly and decisively.
-- when checking the operation of a complex system, operate the system
Hearing protection
Protect your hearing. The life of a sound engineer depends entirely on his condition.
If you're going to be stuck in a noisy truck for six hours, wear headphones for the entire trip. If you
Rules of conduct on stage for vocalists
Do not point the microphone towards monitor speakers.
Final word
In order to work successfully in music production, you must really love your job. You need to have a considerable sense of humor and be able to instantly analyze a lot of details, you need to be able to
Panasonic and the Russian Railways Museum
Vladimir Dunkovich: Stage mechanics control systems.
Synchronization. New level of show. OSC for the show
Maxim Korotkov about the realities with MAX\MAX Productions
Konstantin Gerasimov: design is technology
Alexey Belov: The main one in our club is a musician
Robert Boym: I am grateful to Moscow and Russia - my work is listened to and understood here
pdf "Showmasters" No. 3 2018 (94)
Four concerts from one console at the Munich Philharmonic Gasteig
20 years of Universal Acoustics: a story with continuation
Astera wireless solutions on the Russian market
OKNO-AUDIO and seven stadiums
Ilya Lukashev about sound engineering
Simple Way Ground Safety - safety on stage
Alexander Fadeev: the path of a beginning lighting artist
What is a rider and how to compose it
Stupid way to process a barrel
pdf "Showmasters" No. 2 2018
Panasonic at the Jewish Museum and Tolerance Center
Concerts "BI-2" with orchestra: traveling gothic
Dmitry Kudinov: a happy professional
Sound engineers Vladislav Cherednichenko and Lev Rebrin
Lights on Ivan Dorn's "OTD" tour
Ani Lorak’s show “Diva”: Ilya Piotrovsky, Alexander Manzenko, Roman Vakulyuk,
Ani Lorak’s show “Diva”: Ilya Piotrovsky, Alexander Manzenko, Roman Vakulyuk,
Everything I know I learned on my own. I read, observed, tried, experimented, made mistakes, remade again. Nobody taught me. At that time in Lithuania there were no special educational institutions that would teach how to work with lighting equipment. In general, I believe that this cannot be learned. To become a lighting designer, you need to have something like that “inside” from the very beginning. You can learn to work with the remote control, programming, you can learn all the technical characteristics, but you cannot learn to create.
Ani Lorak’s show “Diva”: Ilya Piotrovsky, Alexander Manzenko, Roman Vakulyuk,
The new design possibilities for active spaces should not be confused with the 'assisted reverberation' that has been used since the 1950s at the Royal Festival Hall and later at Limehouse Studios. These were systems that used tunable resonators and multi-channel amplifiers to distribute natural resonances to the desired part of the room.
their results are below. Participants in the Show Technology Rental Club actively discussed this topic.
We offered to answer several questions to specialists who have been in our business for many years,
and their opinion will certainly be interesting to our readers.
Andrey Shilov: “Speaking at the 12th winter conference of rental companies in Samara, in my report I shared with the audience a problem that has been greatly troubling me for the last 3-4 years. My empirical research into the rental market led to disappointing conclusions about a catastrophic drop in labor productivity in this industry And in my report, I drew the attention of company owners to this problem as the most important threat to their business. My theses raised a large number of questions and a long discussion on forums on social networks."
After the period of the first gramophones, which universally used horn loudspeakers, the popularity of the latter declined sharply due to their relatively large size, complexity of manufacture and therefore high cost. Despite the fact that today wideband horn systems are used only by a few enthusiasts, most experts unanimously note a number of sound advantages inherent in this type of loudspeaker, especially the high degree of realism and “presence”. The article briefly outlines the history of horn loudspeakers, and in more detail = theoretical and practical information necessary for competent design. Data are provided for various types of horns.
An ideal exponential horn consists of a straight circular tube whose cross-section increases logarithmically with the distance from the throat (where the loudspeaker is mounted) to the mouth. The lowest bass notes require a very large mouth area (2-3 square meters) and a horn itself at least 6 m long. In contrast, the highest notes require a horn measuring only ten centimeters. For this reason, most full-range horn systems include many individual loudspeakers, each with an appropriate length and mouth area. To accommodate these combinations within a reasonably sized cabinet, bass and even midrange horns are square-sectioned and “rolled” in a complex manner. Unfortunately, the inevitable limitations and compromises caused by axial and circular alignment deviations can cause major changes in frequency response. The art of designing a loudspeaker system of reasonable size and cost is to not sacrifice the amazing realism inherent in the ideal horn.
The efficiency of a horn system is usually 30 to 50% = a very impressive value compared to 2 - 3% for a bass reflex and less than 1% for a closed design. The main reasons for the lack of popularity of horns are their size and high cost. The total size of the bass section, even successfully folded into a cabinet, will be much larger than a bass reflex or closed box with a comparable lower cutoff frequency.
But, although curious designs of straight horns 6 m long are sometimes encountered, excellent results can be obtained from horns of a more convenient size; for example, a complete system can be folded into a housing with a volume of only 150-200 liters, which is already quite acceptable for indoor use. The cost of making the cabinet is usually seen as the main obstacle, and rightly so, since the amount of work involved in making a folded horn is significantly greater than that of other types of designs. In addition, this work requires highly qualified performers and is poorly adapted to “in-line” methods. However, this in no way means that building a folded horn is beyond the capabilities of a trained do-it-yourselfer, not to mention professionals, and it is for them that this article is intended.
1.4. Loudspeakers
Classification of loudspeakers: according to the method of sound emission, according to the width of the operating frequency band, according to the principle of operation. Main operational characteristics of loudspeakers: total electrical resistance, electrical power (nominal and nameplate), frequency response characteristics.
8.3. Horn loudspeakers.
One of the most common types of audio equipment widely used nowadays is horn loudspeakers.According to GOST 16122-87, a horn loudspeaker is defined as “a loudspeaker whose acoustic design is a rigid horn.” Thus, a horn can be considered a full-fledged acoustic design along with those discussed earlier in section 8.2.3. The ability of horns to amplify and direct sound in the desired direction (long used in the creation of musical instruments) led to the fact that horn loudspeakers began to be used from the very beginning of the development of electrical engineering, they appeared even earlier than diffuser loudspeakers.
However, the creation of a real horn loudspeaker with a design very close to the modern one begins in 1927, when famous engineers from Bell laboratories (USA) A.Thuras and D.Wente developed and patented a “compression horn emitter” the next year. An electromagnetic transducer with a frameless coil made of aluminum tape wound on an edge was used as a loudspeaker (driver). The driver diaphragm was made from a downward facing aluminum dome. Even then, both the pre-horn camera and the so-called Wente body were used (we will talk about them in more detail later). The first commercially produced model 555/55W (form. "Western Electric") was widely used in cinemas in the 30s.
A significant step towards expanding the range towards low frequencies was the invention of P. Voigt (England), where it was first proposed to use “folded” horns, which are widely used today. The first complex designs of curled low-frequency horns for high-quality acoustic systems were developed by Paul Klipsh in 1941 and were called Klipschhorn. Based on this design with a horn design, the company still produces high-quality acoustic systems.
It should be noted that in Russia the first samples of horn loudspeakers were created in 1929 (engineers A.A. Kharkevich and K.A. Lomagin). Already in 1930-31, powerful horn loudspeakers up to 100 W were developed for sounding Red and Palace Squares.
Currently, the scope of application of horn loudspeakers is extremely wide, including sound systems for streets, stadiums, squares, sound reinforcement systems in various rooms, studio monitors, portal systems, high-quality household systems, public address systems, etc.
Causes The spread of horn loudspeakers is due primarily to the fact that they are more efficient, their efficiency is 10%-20% or more (in conventional loudspeakers the efficiency is less than 1-2%); In addition, the use of rigid horns allows the formation of a given directivity characteristic, which is very important when designing sound reinforcement systems.
How they work First of all, the horn loudspeaker (RG) is an acoustic impedance transformer. One of the reasons for the low efficiency of direct radiation GG is the large difference in density between the diaphragm material and the air, and therefore the low resistance (impedance) of the air medium to vibrations of the loudspeaker. A horn loudspeaker (through the use of a horn and a pre-horn chamber) creates additional load on the diaphragm, which provides better impedance matching conditions and thereby increases the radiated acoustic power. This makes it possible to obtain a large dynamic range, lower nonlinear distortion, better transient distortion and provide less load on the amplifier. However, when using horn loudspeakers, specific problems arise: to emit low frequencies, it is necessary to significantly increase the size of the horn; in addition, high sound pressure levels in a small pre-horn chamber create additional nonlinear distortions, etc.
Classification: horn loudspeakers can be divided into two large classes - wide-necked and narrow-necked. Narrow-neck RGs consist of a specially designed dome loudspeaker called a driver, a horn, and a pre-horn chamber (often with an additional insert called a phase shifter or Wente body). Wide-neck RGs use conventional high-power dynamic direct-radiation loudspeaker heads and a horn whose throat diameter is equal to the diameter of the head.
In addition, they can be classified according to the shape of the horn: exponential, convoluted, multi-cell, bipolar, radial, etc. Finally, they can be divided into frequency domain playback: low-frequency (usually collapsed), mid- and high-frequency, as well as Areas of use in official communications (for example, megaphones), in concert and theater equipment (for example, in portal systems), in sound systems, etc.
Device Basics: The main elements of a narrow-neck horn loudspeaker, shown in Fig. 8.32, include: a horn, a pre-horn chamber and a driver.
Horn - is a pipe of variable cross-section on which the driver is loaded. As noted above, it is one of the types of acoustic design. Without decoration, the loudspeaker cannot emit low frequencies due to the short circuit effect. When installing a loudspeaker in an infinity screen or other type of design, the acoustic power emitted by it depends on the active component of the radiation resistance Cancer=1/2v 2 Rizl. The reactive component of the radiation resistance determines only the added mass of air. At low frequencies, when the wavelength is greater than the size of the emitter, a spherical wave propagates around it, while at low frequencies the radiation is small, the reactance predominates, as the frequency increases, the active resistance increases, which in the spherical wave equals Rizl= cS(ka) 2 /2 (in a plane wave it is greater and equal Rizl= WithS),S is the area of the emitter, a is its radius, k is the wave number. A special feature of a spherical wave is that the pressure in it drops quite quickly in proportion to the distance p~1/r. It is possible to provide radiation at low frequencies (i.e. eliminate the short circuit effect) and bring the waveform closer to a flat one if the emitter is placed in a pipe whose cross-section increases gradually. This pipe is called mouthpiece
The entrance hole of the horn in which the emitter is located is called throat, and the output hole emitting sound into the environment is mouth. Since the horn must increase the load on the diaphragm, the throat must have a small radius (area) for effective energy transformation to occur. But at the same time it must have a sufficiently large diameter of the mouth, because in narrow pipes, where the wavelength is greater than the radius of the outlet -a-, (i.e. the condition >8a is met), most of the energy is reflected back, creating standing waves, this phenomenon is used in musical wind instruments. If the pipe opening becomes larger (<a/3),то Rизл приближается к сопротивлению воздушной среды и волна беспрепятственно излучается в окружающее пространство устьем рупора.
Generator shape the horn must be chosen in such a way as to reduce the "spreading" of energy, i.e. rapid decrease in sound pressure, therefore, transform the spherical shape of the wave front so that it approaches a plane wave, which increases the radiation resistance (in a plane wave it is higher than in a spherical wave) and reduces the rate of pressure decrease; in addition, the choice of the shape of the generatrix makes it possible to concentrate sound energy in a given angle, i.e., it forms the directivity characteristic.
Thus, the horn should have a small throat size, and the cross-section at the throat should slowly increase, while the size of the mouth should be increased. In order for large mouth sizes to be achieved with an acceptable axial length of the horn, the rate of increase in the horn cross-section must increase as the cross-sectional area increases (Fig. 8.33). This requirement is met, for example, by the exponential shape of the horn:
Sx=S 0 e x , (8.2)
where So is the cross-section of the horn throat; Sx is the cross section of the horn at an arbitrary distance x from the throat; is an indicator of horn expansion. The unit of is 1/m. The horn expansion index is a value measured by the change in the horn cross-section per unit of its axial length. An exponential horn is shown in Fig. 2, where it is shown that the axial length of the horn dL corresponds to a constant relative change in the cross section. Analysis of the wave processes occurring in an exponential horn shows that the radiation resistance to which the radiator is loaded depends on frequency (Fig. 8.34). It follows from the graph that in an exponential horn the wave process is possible only if the oscillation frequency of the emitter exceeds a certain frequency called critical(fcr). Below the critical frequency, the active component of the radiation resistance of the horn is zero, the resistance is purely reactive and equal to the inertial resistance of the air mass in the horn. Starting from a certain frequency, which is approximately 40% higher than the critical one, the active resistance of radiation exceeds the reactive resistance, so the radiation becomes quite effective. As follows from the graph in Fig. 8.34, at frequencies more than four times higher than the critical frequency, the radiation resistance remains constant. The critical frequency depends on the horn expansion ratio as follows: cr= s/2, Where With - sound speed. (8.3)
If the speed of sound in air at a temperature of 20 degrees is 340 m/sec, you can obtain the following relationship between the horn expansion indicator and critical frequency f cr (Hz): ~0.037f cr.
Not only the value of the critical frequency of the horn, and therefore the frequency response of the radiation resistance, but also the dimensions of the horn depend on the horn expansion index. The axial length of the horn can be determined from formula (1) at x=L as:
L=1/ ln S l /S 0 (8.4)
From expression (3) we can draw the following conclusion: since in order to reduce the critical frequency of the horn, the horn expansion index (2) should be reduced, the axial length of the horn L should thereby increase. This dependence is the main problem with the use of horn loudspeakers in high-quality loudspeaker systems and is the reason for the use of "rolled" horns. It should be pointed out that when constructing a graph of the radiation resistance of an exponential horn (Fig. 8.36), the reflection of waves from the mouth into the horn, which always partially occurs for horns of finite length, is not taken into account. The resulting standing waves create some fluctuations in the radiation resistance values. Reflection of sound from the mouth of the horn occurs only in the low frequency region. As the frequency increases, the acoustic properties of the media (in the horn and outside the horn) are leveled out, sound is not reflected into the horn, and the input acoustic impedance of the horn remains almost constant.
Pre-horn camera: Since the radiated acoustic power of a loudspeaker depends on the active resistance of radiation and the oscillatory speed of the emitter, to increase it in narrow-necked horn loudspeakers, the principle of acoustic transformation of forces and velocities is used, for which the dimensions of the throat of horn 2 are reduced several times in comparison with the dimensions of emitter 1 (Fig. 8.35). The resulting volume between the diaphragm and the throat of horn 3 is called the pre-horn chamber. We can conditionally imagine the situation in the pre-horn chamber as oscillations of a piston loaded on a wide pipe with area S 1, which turns into a narrow pipe S 0 (Fig. 8.35). If the piston diaphragm were loaded only on a wide pipe with an area equal to the area of the diaphragm (wide-neck horn) , then its radiation resistance would be equal Rizl= WithS 1 , and the acoustic power emitted by it would be approximately equal to Ra= 1/2R izl v 1 2 =1/2 WithS 1 v 1 2 (these relations are strictly satisfied only for a plane wave, but can be applied in this case under certain assumptions.) When installing the diaphragm in the pre-horn chamber, i.e. when it is loaded onto the second pipe with a narrow inlet, additional resistance (impedance) to the vibrations of the diaphragm arises (due to the reflected wave arising at the junction of the two pipes). The value of this impedance is Z L (referred to the point of entry into the second pipe, i.e. at x = L ) can be determined from the following considerations: if we assume that the air in the pre-horn chamber is incompressible, then the pressure p created in the chamber under the action of force F 1 on a piston (diaphragm) with area S 1, is transmitted to the air in the throat of the horn and determines the force F 0 , acting in the throat of a mouthpiece with an area S 0 :
p=F 1 /S 1 , F 0 =pS 0 (8.5).
From this we obtain the following relations: F 1 /S 1 =F 0 /S 0 , F 1 /F 0 =S 1 /S 0 . The ratio of the emitter area to the horn throat area S 1 / S 0 is called acoustic transformation coefficient and is designated P. Therefore, the relationship of forces can be represented as: F 1 =nF 0 . From the condition of equality of the volumetric velocities of the diaphragm and air at the mouth of the horn (i.e., from the condition of maintaining the volume of air displaced by the diaphragm during displacements from the pre-horn chamber), the following relations are obtained: S 1 v 1 = S 0 v 0 or: v 0 /v 1 =S 1 /S 0 =n.
(8.6).<. V 0), значит, она испытывает большее сопротивление среды при колебаниях. Значение Z L в таком случае (учитывая, что импеданс по определению есть отношение силы к скорости колебаний Z L =F 1 /v 1) будут равны с учетом соотношений (8.5)и (8.6): Z L =F 1 /v 1 =S 1 p/v 1 =S 1 p/{v 0 S 0 /S 1 }=(S 1 2 /S 0 2)S 0 p/v 0 . (8.7)
The obtained relationships allow us to draw the following conclusion: the diaphragm, under the influence of a greater force (F 1 > F 0), oscillates at a lower speed (V 1
If the piston stood at the inlet of a narrow pipe, then its resistance would be equal to Rizl=cS 0, while by definition Rizl=F 0 /v 0 =S 0 p/v 0, i.e. S 0 p/v 0 =сS 0 , substituting this expression into formula (8.7) we get: Z L 1 2 /S 0 2 =(S 0 With)S 1 /S 0 ) S 1 =(S
With. (8.8) This multiplication of impedance сS 0 by a coefficient 1 2 /S 0 2 ) (S
is equivalent to the use of some kind of step-down transformer, as can be seen in the corresponding equivalent electrical circuit (Fig. 8.37)
Therefore, if, in the presence of additional resistance, the radiated acoustic power increases and is equal to: Ra=1/2 Z =1/2 WithS 1 v 1 2 (S 1 /S 0 ). (8.9)
Thus, the use of acoustic transformation due to the pre-horn chamber makes it possible to increase the acoustic power by (S 1 / S 0) times, which significantly increases the operating efficiency of the horn loudspeaker. The value of the acoustic transformation coefficient is limited, since it depends on the area of the emitter (S 1) and the area of the horn throat (So). An increase in the emitter area is associated with an increase in its mass. A large mass emitter has a high inertial resistance at high frequencies, which becomes comparable to the radiation resistance. As a result, at high frequencies the oscillatory speed decreases, and therefore the acoustic power. The acoustic transformation coefficient increases as the horn throat area decreases, but this is also acceptable within certain limits, because leads to an increase in nonlinear distortions. Typically, the acoustic transformation coefficient is chosen to be about 15-20.
The efficiency of a horn loudspeaker can be approximately estimated using the formula: Efficiency=2R E R ET /(R E +R ET ) 2 x100%, (8.10)
where R E is the active resistance of the voice coil, R ET =S 0 (BL) 2 /cS 1 2, where B is the induction in the gap, L is the length of the conductor. The maximum efficiency of 50% is achieved when R E = R ET, which cannot be achieved in practice.
Nonlinear distortions in horn GGs are determined both by ordinary reasons that arise in loudspeaker heads: nonlinear interaction of the voice coil with the magnetic field, nonlinear flexibility of the suspension, etc., and by special reasons, namely high pressure in the throat of the horn, and thermodynamic effects begin to affect, as well as nonlinear air compression in the pre-horn chamber.
Emitter, which is used for horn loudspeakers is a conventional electrodynamic loudspeaker. For wide-neck horns (without a pre-horn chamber) this is a powerful low-frequency loudspeaker. Wide-neck horns are now used as low-frequency design in a number of designs of acoustic units, for example Genelek (this technology is called waveguide TL), portal sound systems, etc.
Narrow throat horn loudspeakers use special types of electrodynamic loudspeakers (commonly called drivers An example of the design is shown in Fig. 8.32. As a rule, they have a dome diaphragm made of hard materials (titanium, beryllium, aluminum foil, impregnated fiberglass, etc.), made together with a suspension (sinusoidal or tangential corrugation). A voice coil is attached to the outer edge of the diaphragm (frame made of aluminum foil or rigid types of paper with two or four layers of winding). The suspension is secured with a special ring on the upper flange of the magnetic circuit. An anti-interference liner (Wente body) is installed above the diaphragm - acoustic lens to align the phase shifts of acoustic waves emitted by different parts of the diaphragm. Some high-frequency models use special annular diaphragms.
To analyze the operation of horn loudspeakers in the low frequency region, the method of electromechanical analogies is used. The calculation methods mainly use the Thiele-Small theory, on which the calculation methods for conventional cone loudspeakers are based. In particular, measuring the Thiele-Small parameters for the driver allows one to evaluate the shape of the frequency response for low-frequency horn loudspeakers. Figure 8.37 shows the shape of the frequency response, where the inflection frequencies of the curve are determined as follows:f LC =(Q ts)f s /2; f HM = 2f s / Q ts ;
f HVC =R e / L e ; f HC =(2Q ts)f s V as /V fs ;where Q ts is the overall quality factor; f s \resonant frequency of the emitter; R e , L e – resistance and inductance of the voice coil, V fs – equivalent volume, V as – volume of the pre-horn chamber.A complete calculation of the structure of the sound field emitted by horn loudspeakers, including taking into account nonlinear processes, is carried out using numerical methods (FEM or BEM), for example, using software packages:
http://www.sonicdesign.se/ ;http://www.users.bigpond.com/dmcbean/ ; http:/melhuish.org/audio/horn.htm. Since one of the main tasks of horn loudspeakers is the formation of a given directivity characteristic, which is of fundamental importance for sound systems for various purposes, a wide variety of
= horn shapes, the main ones being the following:
=exponential horns that were designed to combat the exacerbation of directivity characteristics at high frequencies (Fig. 8.38). A sectional horn consists of a number of small horns connected together by throats and mouths. In this case, their axes turn out to be fanned out in space, although the directionality of each cell becomes sharper with frequency, the overall directionality of the group emitter remains wide.
=radial the horn has different curvature along different axes (Fig. 8.39a, b). The width of the radiation pattern is shown in Fig. 8.43b, from which it can be seen that in the horizontal plane it is almost constant, in the vertical area it decreases. These types of horns are used in modern studio monitors, in addition, they are used in cinema systems.
To expand the directivity characteristics in horn loudspeakers, they are also used acoustic dissipative lenses (Fig. 8.40).
=diffraction the horn (Fig. 8.41a, b) has a narrow opening in one plane and a wide opening in the other. In a narrow plane it has a wide and almost constant radiation pattern, in a vertical plane it is narrower. Variants of such horns are widely used in modern sound reinforcement technology.
Horn uniform coverage(after a number of years of research were created at JBL), they allow you to control the directivity characteristics in both planes (Fig. 8.42a, c).
Special shape folded horns used to create low-frequency emitters Fig. 8.43. The first cinema systems with a folded horn for cinema were created back in the 30s. Rolled horns in both narrow-neck and wide-neck loudspeakers are now widely used for high-quality control units, for powerful acoustic systems in concert and theater equipment, etc.
There are currently other types of horns in production, both for sound reinforcement equipment and for household audio equipment. In the practice of scoring large concert halls, discos, stadiums, etc., suspended sets of horn loudspeakers called clusters.
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