Make your everyday life more enjoyable with the HP MP250, a smart projector that can be used both at home and outdoors.
If you write the contents roughly
The 6W speaker unit produces sound in all directions of 360 °, so there is no problem even in a slightly lively scene.
The smart projector "HP MP250" has Wi-Fi, Bluetooth, screen mirroring, oh ... → Continue reading
"Bouncy" is a new age video media that delivers cutting-edge information that shows the future lifestyle in a format that is easy to see on smartphones. Tomorrow, 10 years later, or 100 years later. Every day, we will deliver various events that shape our future with easy-to-understand videos from the editorial department's perspective. I hope that it will be a small opportunity for someone to think about the future, move their hands to realize their dreams, and take that step.
Wikipedia related words
If there is no explanation, there is no corresponding item on Wikipedia.
speaker(British: speaker）[Annotation 1], More formallyLoudspeaker(British: loudspeaker) Iselectoronic signalsThesoundIt is a device that changes to..ElectricalvibrationA device that transforms into physical vibration.Audio equipmentA kind of.Without extending the ending, "SpeakerAlso, in Kanji expression, it is also called "loudspeaker".
Strictly speaking, "speaker" is a "speaker system" (= enclosure, that is, a box or container).Later), When referring to the whole (the one contained in) and the "speaker unit" (Later) May be the only point.When it is necessary to clarify which one is being referred to, it is called "speaker system" or "speaker unit".
A speaker is a device that converts an electrical signal that expresses acoustics into physical sound, that is, vibration of air.For example, sounds such as voices and musical instrument sounds (Sound wave)MicrophoneThe electrical signal (electrical vibration) obtained by converting it with a synthesizer or the like is converted into a sound wave and released into space, or the electrical signal (electrical vibration) electrically generated by a synthesizer or the like is converted into a physical sound that can be heard by humans. It is a device that can be thrown away.[Annotation 2]
Generally, a speaker that converts an input electric signal into sound as faithfully as possible is called a "good speaker" or a "high-performance speaker".つまり元の電気信号のThat is, of the original electrical signalWaveformAnd when comparing the waveforms of the sound emitted from the speaker, there is a difference between those waveforms (歪 み) OccursnoiseIt is said that "performance is low".If the performance is good, the price tends to be high.Also, if the speaker size is too small, the bass (signal) tends to be hardly converted into sound.
Speakers are selected for each application, taking into consideration the cost and the final product size to be realized.For example, component stereos that are used stationary in homes and audio rooms, especiallyLuxury audioFor speakers, combine multiple high-performance and expensive units, select a unit with a diameter of several tens of centimeters for bass, and incorporate it into a box-shaped enclosure with a height of several tens of centimeters to 1 m or more. Generally, a "speaker system" is built up, and thanks to this, many of them convert electrical signals into sound fairly faithfully.Instead, it's so big and heavy that it takes up space in the room and can't be easily moved.On the other hand, for portable radios that are supposed to be carried in the event of a disaster, the highest priority is to be easy to carry, and the product must be made absolutely small and light, so designers choose small and light speakers. As a result, a speaker with almost no bass is selected.This is especially true for cheap portable radios.However, with such a portable radio for disasters, it is enough to hear the announcer's voice and understand the meaning of the words, so that's fine.Speakers for portable radios should never be large and heavy.
Therefore, the properties of speakers often have a so-called "trade-off" relationship, that is, "if you stand up there, you can't stand here", and the designer considers the balance of cost, size, weight, and performance. While doing so, I will choose a speaker.
The dynamic speaker was invented by Edward W. Kellogg and Chester W. Rice in 1925 and was patented in the United States in April 1929.
Contrary to dynamic microphones, which generate electrical signals from voice, dynamic speakers generate sound from electrical signals.
When a coiled wire called a voice coil is hung in a circular gap between the poles of a permanent magnet and an AC audio signal is passed through it, the coil rapidly trembles back and forth according to Faraday's law.By fixing a diaphragm (usually a cone) to this coil, the diaphragm moves back and forth, pushing air and generating sound waves.In addition to this most common method, there are several alternative techniques that can be used to convert electrical signals into sound.
Speaker type / classification
Classification by unit conversion method
- Dynamic type
- Capacitor type (electrostatic type)
- Ribbon type
- Ion type (discharge type)
- Magnetic type
- Piezoelectric type
Classification by shape of diaphragm
- Cone type
- Dome type
- Flat type
- Bending wave type
- Walsh unit
- Manger unit
- Hail driver
- Linear driver
Classification by arrangement of diaphragm
- Plays everything from bass to treble with one type of speaker unit.
- Multiple types of speaker units share the range to be reproduced (2 ways, 3 ways, etc. increase depending on the number of units).
- Vertical twin (virtual coaxial)
- In the multi-way, the bass unit is placed above and below the treble speaker unit.
- Coaxial unit
- A speaker unit for treble is built in the center of the speaker unit for bass, and the center position of each unit is matched.
Vibration speaker without a specific diaphragm
Instead of a specific diaphragm such as cone paper, install a vibrating body (such as a piezoelectric vibrator in a heat-resistant resin case) directly on the wall, floor, etc. of the house.AutomobileIt is a speaker that uses a diaphragm that resonates with the ceiling and flowers of the building.They are called vibration speakers, resonance speakers, and conduction speakers.
In addition, discharge type (ion type) speakers andThermophoneThere are also speakers that generate sound without using a diaphragm.放電型スピーカーはDischarge type speakerhigh frequencyDischargeIt uses the vibration of the air generated inTransient responseIs excellent.ThermophoneUses the thermoacoustic effect to generate sound by using the change in pressure due to periodic heat fluctuations.It was forgotten for a long time because it didn't get enough sound pressure,carbon nanotubeWith the invention of new materials such as, application to sheet-shaped speakers is being researched..
Classification by enclosure
- Flat baffle/ (Dipole type)
- 型 型
- Bass reflex type
- Dumped bass reflex type
- Drone cone type
- ASW type(Kelton method / tuning duct method)
- Double bass reflex type
- Resonance tube method
- Transmission line
- IR method
- Horn type
* These are often used in combination.
Classification by shape and size
Classification by use
- Pure Audiouse
- Monitor speakeruse
- PA/ SR / For loudspeaker
- For musical instruments --Structurally the same as an active speaker, but considered as part of the target instrument.
- For underwater
- For embedded (mobile phones, etc.)
- Military (Acoustic weaponother)
- Other special uses
Classification by presence / absence of built-in amplifier
There are types that have a built-in amplifier on the speaker system side and types that do not.
The speaker system with built-in amplifier is customarily "Active speakerThose without a built-in amplifier are customarily called "passive speakers".It's just a convention.There is no deep meaning.
Driver (speaker unit)
The core part that makes sound is "Speaker unit"(Or simply" unit ").In English "driver" driverI also call it.This is the core part of producing sound, and although it produces sound by itself, it is rarely used in the "bare" state, such as radios and televisions.CaseBuilt into (recentlyPortable audioHas become overwhelmingly dominant, and large audio equipment has been shunned.)Component stereoIn the case of a (component) speaker, it is used in a state where it is attached to an enclosure (that is, something like a box or container).Some super tweeters are not put in an enclosure and are used alone in a state called "pon holder".
One unit of peopleAudible rangeIt would be ideal if it could reproduce everything (about 20-20,000 Hz), but in reality it is difficult to make.So specificfrequencySpeaker units that are good at bands (ranges) are made, and by combining multiple units of different types that are good at different frequency bands, it is done to cover a wide frequency range as a whole. There is.Speaker units are classified as follows according to the frequency band in which they are good at.
- full range ――Roughly for all bands (Even if you say "for all bands", the performance is basically good only in the midrange, and in general, it is not possible to faithfully reproduce all bands, and it is high. In many cases, the reproducibility of either the range, the bass range, or both is slightly inferior, and in particular, in the ultra-bass range and the ultra-treble range, there is almost no sound.)
- Subwoofer --For super bass
- woofer --For bass
- --For mid-low range
- squawkerOr midrange-for midrange
- Tweeter --For treble
- Super tweeter --For super treble
In addition, what range of frequencies is ultra-bass, bass, mid-bass, mid-range, treble, and ultra-treble?There is no strict definition.
A speaker system is made by combining the above-mentioned driver (speaker unit) and enclosure.
- Types and classifications of speaker systems
Below is a list of speaker system types
- 1-way speaker (also known as "full-range speaker")-Since there is only one speaker unit, it is customary to select a unit called "full-range unit" that has excellent midrange and covers the entire range moderately. It is a means.[Annotation 3]
- 2-way speaker-The range is divided into two and played back by two types of speaker units.It mainly consists of "woofer + tweeter" (with exceptions).
- 3-way speaker-The range is divided into three and played back by three types of speaker units.Mainly composed of "woofer + squawker + tweeter" (with exceptions).
- 4-way speaker (or higher) --The range is divided into 4 (or higher) and played back by 4 types (or higher) of speaker units. Unlike the 2-way and 3-way, the composition is different.
Another example of a 2-way speaker system.This is perforatedBass reflex type.
The pattern on the left is used without driver protection.The right is metal to protect the drivermeshA pattern that is used by attaching to the surface.If you inadvertently hit your toes or objects without anything to protect, the thin film of the driver will break and break.
Speakers with 2 or more ways (speakers other than full range) are called multi-way speakers.In a multi-way speaker, it is usual to use an electric circuit or an electronic device that limits the range so that the range of each unit does not overlap.In front of the power amplifier (VoltageIt may be divided at the signal stage) and driven by a different power amplifier for each range, but in many cases it is driven by a power amplifier.electricityIt is split after amplification.The frequency that corresponds to the boundary of the range of each unit is called the crossover frequency. There is one crossover frequency for the 2-way and two crossover frequencies for the 1-way.
There is an opinion that the position of the instrument and voice is blurred compared to the full range because the mounting position of each unit is inevitably different in the multi-way speaker.To solve this problem, a speaker system in which two woofers are placed so as to sandwich the top and bottom of the tweeter and the mounting positions are apparently matched is also on the market.As a special example, there is a 2-way unit that is made into one unit by incorporating a tweeter in the center of the woofer, and is called a coaxial 1-way unit.
In addition, in the above speaker system,SubwooferMay be added as a separate housing.This is a dedicated speaker system for producing only bass (ultra-bass / deep bass).Home theaterIt is attached to most of the products and can be said to be widely used as AV equipment.For subwoofers,Dolby DigitalIn such systems, it may be added as an LFE channel (0.1ch), but this does not divide the range in charge of the speaker, but adds ultra-bass as an independent channel.
Dynamic speaker unit
Most of the speaker units incorporated in general audio equipment adopt this method. The basic structure has not changed since it was invented by Chester W. Rice and Edward W. Kellogg in 1924, because this method is simple and excellent.
The dynamic speaker unit has a donut shapepermanent magnetIs used.A cylinder "Voice Coil" with a slightly smaller diameter is inserted into the cylindrical space that corresponds to the hole in the donut.ボイスコイルはVoice coilcoilIt is a kind of paper or plastic cylinder with a wire wound around it.When an audio signal flows through this wire,electromagnetTherefore, the voice coil vibrates in the front-back direction according to the waveform.ボイスコイルにはFor the voice coilDiaphragmIs directly connected, and when this diaphragm vibrates together, a sound having a waveform equal to that of an audio signal is radiated into the air.これはthis isLinear motorIt can be said that the dynamic type speaker is a kind of linear motor.
Each of the above parts is fixed to a frame called a frame, and is completed as one unit.永久磁石はフレームに強固に固定されるが、ボイスコイルと振動板は振動する必要があるため、ボイスコイルはThe permanent magnet is firmly fixed to the frame, but the voice coil and diaphragm need to vibrate, so the voice coilDamperEach diaphragm is fixed to the frame via a flexible membrane called an "edge" stretched around its outer circumference.The damper and edge are suspensions (suspension devices) that fix the diaphragm to the frame, but they do not interfere with the movement in the front-back direction.また、ダンパーは振動板のAlso, the damper is a diaphragmNatural vibrationIt also plays a role in suppressing.The frame usually has screw holes that allow the unit to be attached to an enclosure or the like.
High for permanent magnets used in magnetic circuitsMagnetic flux densityIs required.Cost performanceExcellent inFerrite magnetIs often used, but the magnetic force is strong for small speakers.Samarium cobalt magnet,Neodymium magnetEtc. are also used.なお、以前はIn the past,Alnico magnetWas used mainly for high-end products, but it is now rarely seen due to the high nickel price.またAlsoAlnico magnetHas the advantage of low magnetoresistance, but also has the disadvantage of requiring a special magnetic circuit that is easy to demagnetize.In addition, there is a speaker unit that uses an electromagnet in a magnetic circuit called an excitation type, and it was often used from the 1920s to around 1960 when there was no permanent magnet with a strong magnetic force, and it is still used by some enthusiasts for production. However, a dedicated DC power supply device is required for the magnetic circuit, and its use is quite large.
Diaphragm structure of dynamic speaker
The performance required for an ideal speaker is that it is faithful to the original sound and has no distortion, that it is a point sound source, that it emits sound with the same sound pressure and the same sound quality in all directions, and so on.In order to realize these, the shape and size of the diaphragm and the mounting method have been devised.
The mainstream diaphragm shape is a cone type (concave conical shape) for bass, and a cone type or dome shape (bulging hemisphere) for treble. The flat type became popular in the early 1980s, but it is rarely used now.Most of them are perfectly circular when viewed from the front, but oval or polygonal ones are also used for built-in TVs.
There is also a "double cone type" (also called a sub cone type or mechanical 2-way) that aims to reproduce a wide band by attaching a small cone type diaphragm to the center of the large cone type diaphragm.
Material of the diaphragm of the dynamic speaker
The diaphragm has split vibration and共鳴It is required that there is little natural vibration due to this and that the conversion efficiency is good.このため、硬く（＝高Therefore, it is hard (= high)Young's modulus), A large and lightweight material is used.It is also important that there is little deterioration over time.It is not easy to find a material that satisfies all of these at a high level.For this reason, it is common to change the material according to the range that the unit is in charge of.Even if it is preferable that the material of the diaphragm is lightweight, there is a limit.If it is too lightweight, the sound pressure level of the midrange and even the treble will be too high compared to the bass.This is a preferable property for tweeters, but not for woofers.Therefore, the diaphragm of the speaker unit for a woofer is often heavier than that of other speaker units.
- Paper-Most used regardless of age.Due to its moderate internal loss, relatively strong and lightweight, it is widely used from low-priced products to ultra-luxury speakers.It can be used in the entire range, but it is rarely used for high frequencies.pulpPaper with improved properties by mixing various materials is also often used.またAlsoSquirts,KombuThere are also products that use the fiber of.
- resin- polyester,Aramid,polypropylene,Carbon fiberIn many cases, polymer resins such as these are knitted in a woven shape or made into a honeycomb structure.Mainly used for bass to midrange units.silkFibers such as these are used as structural base materials, and these polymer materials are impregnated for the purpose of ensuring strength and improving physical properties.
- Metal- aluminum,Titanium,Boron(boron),beryllium,magnesiumSuch.It can be made thinner and lighter, and while it has a high Young's modulus, it has a small internal loss and is prone to natural vibration.Therefore, it is mainly used for treble units.This is because the diaphragm for treble is small, so the natural vibration can be expelled outside the audible frequency.Treatments such as coating these metals with a diamond thin film, carbonization treatment, nitriding treatment, oxidation treatment, aspherical treatment, coating of a dumping agent, and the like to disperse natural vibrations are also widely performed.
- Wood-A diaphragm made from thinly sliced wood.ビ ク タ ーHas adopted it for speakers and headphones under the name of "Wood Cone", and units for self-made speakers are on sale.
- Other- Synthetic diamond, There are silk and carbon sheets., Neither has become mainstream.
Crossover network (passive network)
Passive elementAn electric circuit for dividing a range composed of only is called a "crossover network" or a "passive network" (or simply a network).
The network isCapacitorとInductorbyLow pass-High passEtc.filterAdjust the imbalance due to the difference in the efficiency of the speaker in each band and the channel divider byresistancebyAttenuatorConsists of.
If the network is not designed correctly,phaseThe characteristics and frequency characteristics deteriorate.For this reason, it is common to build an optimal circuit by repeating measurement and audition for particularly complicated ones.
Complex networks are, in principle, out of phase and difficult to balance by the number of combinations.Therefore, both manufacturers and users have different opinions on whether it is better to divide the range or to have a simple configuration in terms of sound quality.
The most important thing in network design is to set the crossover frequency properly.The more units you have, the wider the range you can play, but the more crossover frequencies you have, the more difficult it is to design your network.
An enclosure is a box in which a speaker unit is mounted.Sound has the property of wrapping around behind obstacles (diffraction), And the lower the tone, the more noticeable.For this reason, if the unit is used as it is exposed, the bass from the back wraps around and cancels each other, and the bass becomes quieter.Therefore, by attaching the unit to the enclosure, the sound emitted from the back is blocked.ユニットをエンクロージャーに組み込んだものをThe unit built into the enclosureSpeaker systemCall it (or just a speaker).Almost all speakers are commercially available in this state.
The enclosure is of the diaphragmreactionVibrates by.また、内部で音が反射してAlso, the sound is reflected insideStanding waveOccurs.Since these deteriorate the sound quality, the strength is secured by reinforcing materials and partition walls.feltAbsorb standing waves with sound absorbing materials such as.The design of this enclosure determines the sound quality of the entire speaker system and is the individuality of the product.In other words, it is theoretically possible to attach the unit to a single board with a huge area in order to make the deterioration of sound quality as close to zero as possible (Flat baffle).However, because it was practically difficult, it became a "box type".
The material of the box is usually required to have no natural vibration, workability and strength.Wood-based material(Veneer,MDF,Particle board,Plywood) Is used.There are resin and metal products, but resin products are small and inexpensive, and metal products are limited to small products and high-end products.
- 型 型 --The box is sealed to completely shield the influence of the sound emitted from the back of the diaphragm.It features a straightforward sound quality with few habits.On the other hand, if the enclosure is too small and the magnetic circuit of the speaker unit is weak, the movement of the diaphragm is restricted, and the sound tends to be clogged with less bass.
- Bass reflex type --Cylindrical through holes (ports / ducts) are provided on the front and back of the enclosure.Helmholtz resonanceResonates and enhances the bass emitted from the back of the unit based on the principle of.This is added to the bass emitted from the front of the diaphragm, and a rich bass is obtained.On the other hand, there is almost no bass that is lower than the resonance frequency.Also, if the design is bad, the sound will have a habit, and wind noise will be produced at the through holes.
- Back load horn type -Inside the enclosure, the sound path (horn) that gradually thickens is folded, and there is an outlet for the horn somewhere in the box.Of the sound emitted from the back side of the diaphragm, the bass is enhanced by the horn, and the middle and treble are attenuated by the bent structure and radiated from the outlet.The bass reflex type has a greater bass enhancement effect than the bass reflex type, but on the other hand, it is difficult to enhance the bass to a lower band as the bass reflex type.It takes time to design and manufacture.It is used for self-made speakers and ultra-luxury products from overseas manufacturers.
The type of enclosure is compatible with the speaker unit.
- Flat baffle-Suitable for units with light diaphragm weight and weak magnetic circuits.A unit with a strong magnetic circuit is prone to overbraking.
- Sealed type-Suitable for units with heavy diaphragms and strong magnetic circuits.When a unit with a light diaphragm weight and a weak magnetic circuit is used, a large internal volume is taken to suppress the influence of back pressure.
- Back load horn-Suitable for units with a light diaphragm and strong magnetic circuit.In combination with a unit with a heavy diaphragm, bass tends to be excessive.A unit with a weak magnetic circuit has insufficient ability to drive the horn, which adversely affects sound quality.
- Bass reflex type-The unit has a wide range of compatibility due to its design.When a unit having a light diaphragm weight and a weak magnetic circuit is used, the internal volume can be smaller than that of the closed type.In a unit with a heavy diaphragm and a strong magnetic circuit, the bass tends to be excessive, so the port is made smaller to weaken the effect.In a unit with a light diaphragm weight and a strong magnetic circuit, the port cross-sectional area is made large to enhance the bass enhancement effect, but the bass enhancement in a too low band is avoided.
In addition, a speaker with a trumpet-shaped curved surface (horn) attached in front of the unit is called "Front road horn typeIs called.This is used in combination with each of the above enclosures and is not a term that refers to the enclosure scheme.Although the directivity can be controlled and the efficiency is excellent, it tends to be large.It is used for ultra-luxury speakers, large self-made speakers, and loud acoustic speakers for concerts.By convention, this term is used only for horns that are larger than a certain size or that are retrofitted.For example, the tweeter unit often has a small horn of several cm integrated from the beginning, but this is not called a front road horn.
Sound quality index
Speakers for audio have been devised in various ways to improve "frequency characteristics," "distortion," "transient characteristics," "directivity," etc., and are used as indicators of sound quality.
- Frequency characteristic --HumanAudible rangeIt is required that the entire pitch can be reproduced and that a uniform sound pressure can be obtained at any frequency.
- Distortion rate-A voice wave similar to the waveform of the voice signal input to the speaker is output, and it is required that no extra sound is added.
- Transient characteristics-When sounds of multiple frequencies are mixed and input to the speakerphaseIs required to be accurate (there is no time lag in those sounds).
- Directivity --The speaker is required to radiate even sound pressure in all directions.
- Sound Preference-A pursuit of sound based on human taste.Color the sound in various ways, such as making the frequency response non-flat, resonating the enclosure, and increasing distortion.
Since the speaker moves a diaphragm having a mass in grams, the distortion is inevitably large.Some properly designed speakers have a distortion factor of less than 100% in the audible range (0.5Hz or higher), but the distortion factor of other devices (CD players, amplifiers, etc.) is still less than 0.01%. Considering that, the distortion factor is more than two orders of magnitude larger.
Generate distortionnon-linearParts include dampers, edges, and poorly designed magnetic circuits.The effect of these non-linearities becomes remarkable in the bass range where the amplitude is large.Equal loudness curveAs shown byHuman capitalHearing is insensitive in the bass range.Therefore, even if the music sounds like the bass, middle, and treble are sounding in a well-balanced manner, the acoustic energy distribution tends to be biased toward the bass range, and the speaker that tries to reproduce (reproduce) the energy distribution is in the bass range. Make a big stroke with.A large stroke makes it easy to step into the non-linear region of the vibration system support member.In addition, since the bass diaphragm is heavy, it generates a counter electromotive force (braking force) due to inertia, which also causes distortion.For this reason, speaker distortion is likely to occur in the low frequency range, and even when actually measured, such a result is obtained.
While audio speakers ideally have a wide directivity, there are also situations where you want to narrow down the directivity and transmit loud sound in a specific direction.For example, announcements at school education sites, transportation information broadcasts,Town missionAnd so on.
Theoretically, the diaphragm should be enlarged to narrow down the directivity, but it is unrealistic because it requires a diameter of several meters or more.Therefore, a speaker equipped with a conical tube called a horn is used as a loudspeaker for the above purpose.
Since the directivity increases as the frequency increases, ultrasonic waves are sent out from a small vibrating part in the form of a beam with strong directivity so that humans can hear it as audible sound using the distortion of the sound.Parametric speakerThere is also that.
- Self-made speaker system
- It is often said that speakers are "self-made" by purchasing commercially available speaker units and making enclosures (wooden boxes or specially shaped containers) to make holes for unit installation. , Says to assemble a speaker unit (and terminals, etc.) into the enclosure.Occasionally, audio magazines and the like feature articles about self-made speakers (systems) (which was very often decades ago).A certain percentage of enthusiastic audiophiles buy (several types) of expensive (discerning) units and combine them to do this.
- Self-made speaker unit (itself)
- If the speaker unit is also simple,paper cupとmagnetとEnamel wireYou can also make your own "paper cup speaker" quite easily using("Paper cup speakers" are of low sound quality to the last. You can easily make a moderately loud speaker.)However, once you have experienced making "paper cup speakers", you can use it as a foothold and enjoy experiments to see how the sound produced by changing materials and structures changes (by ingenuity and trial and error). You can make your own if it has a certain level of performance (even an amateur can use familiar materials).
Assembled speaker units were sometimes sold in magazine appendices.
Based on the existing unit, there are also audiophiles who remodel the unit by replacing the edge with chamois leather etc., replacing it with a self-made diaphragm such as Japanese paper or metal plate, or replacing or adding a stronger magnet. There is a certain number.
- SpeakerelectronicsIn related industry terminology, "rapIs sometimes called.In addition, it should be noted1950 eraIn the old radio-related technical literature up to, it is labeled as "high voice device".
- SpeakermicrophoneIt can also be used as an intercom, etc. for cost reduction (speaker and microphone can be combined with one part).There are also applications such as Yamaha's "SUBKICK" that use dynamic speakers as a sound collecting microphone for bass drums.On the contrary, it is possible to use a microphone as a speaker, but many of them are small and have a delicate structure, and are fragile if care is not taken.
- The frequency of sound that can be heard by the human ear varies from person to person depending on age, etc., but is about 40 to 18,000 Hz when measured as a single sound.However, when playing complex sounds such as music from speakers,The presence or absence of ultra-bass and ultra-treble, which are said to be inaudible, affects the reproduction of the naturalness of the sound.Is known experimentally..Reproduction of the overtone components of sound is particularly important, and in recent years, speakers capable of reproducing sounds exceeding 20,000 Hz have become common.また、音楽記録媒体でも20,000Hzを超える高音域、またはAlso, even with music recording media, the treble range exceeding XNUMX Hz, orSuper treble reproduction over 40,000HzIs possibleSACD"Or"Dvd audio", Limited to a small part,"BD-Audio "is commercially available.また可聴外の超低音については、耳で聞こえなくとも空気の振動として肌やAlso, for inaudible ultra-bass, even if you cannot hear it, it will be a vibration of the air on your skinporesCan be felt in.
- As a special type of enclosure, multiple chambers and port tubes are used to maximize the resonance of the bass to make the capacity smaller than usual, or the enclosure itself is intentionally resonated (box squeal) to produce sound. Many have been developed, such as those that have been designed to release.
- ^ In English, loudspeaker is the more official name. "Speaker" basically means "speaker" or "speaker" and is easily misunderstood, so when referring to a device, I prefer to call it a loudspeaker in English.The term "speaker" is an abbreviated term used only when it is clear to both the speaker and the listener that it refers to the device.
- ^ For devices that produce sound with electricity,chime,buzzer,bellHowever, these only generate sounds with a fixed frequency (one or more), and the principle is different.
- ^ Since it is said to have excellent sound quality in the midrange, vocals, that is, human singing voices, are well reproduced.On the other hand, tweeters and subwoofers can be added later, although they are a little weak in the treble and bass range.It is often used for self-made speakers because it has a simple structure and is relatively low cost, but it is easy to obtain good results.Many of the speakers on the market do not use this for speakers with two or more ways. Since a speaker with two or more ways deviates from the point sound source, which is one of the ideal conditions for the speaker, playback with one full-range unit may be treated as a kind of ideal form.In recent years, there are many full-range units that can reproduce high frequencies far beyond the human audible band, and the range tends to be expanded to the bass side as well.
- ^ Daijisen
- ^ Colin Barras (October 2008, 10). “Hot nanotube sheets produce music on demand”. New Scientist. 2011/2/1Browse.
- ^ a b Daichi Ishii "Speaker diaphragm material: Main materials and technological trends"Journal of the Acoustical Society of Japan, Vol. 66, No. 12, Acoustical Society of Japan, 2010, pp. 616-621," two:10.20697 / jasj.66.12_616, ISSN 0369-4232, NOT 110007989165.
- ^ Acoustical Society of Japan 1996.
- ^ http://www.manabi.pref.gunma.jp/bunrui/gakupro/08000392/
- ^ (Tsutomu Ohashi 2008) Demonstrated that the subject was definitely listening to the sound even if he / she was not aware that he / she had heard the sound by letting the subject listen to the high-pitched sound and measuring the brain wave at that time.
- ^ "DIATONE 70th Anniversary Special Site Special Column Vol.02 "Currently Audio Playback: What High-Resored Data Has Changed, Tomohiro Kaiyama"”(Japanese). Mitsubishi Electric (June 2016). 2016/11/12Browse.
- Acoustical Society of Japan Hen "Sound Everything Small Encyclopedia: From the Mechanism of the Brain Listening to Sound to the Ultrasonic Microscope" Kodansha <Blue Bucks>, December 1996.ISBN 4-06-257150-1. NCID BN15660574.
- Ohashi Riki,Kazuo Okanoya, Et al., "Blessed Sound Experience and Brain: From the Range of Omnidirectional Non-Differentiated Approach",Hideaki KoizumiEdited and edited "Brain Science and Art" Kosakusha, 2008.ISBN +978-4-87502-414-9. NCID BA88052217.