The major difference between an electric guitar and an acoustic guitar is that it is equipped with a special pickup, which is composed of permanent magnets and coils. The magnetic lines of force are cut through the vibration of the strings to generate electronic signals with the same audio frequency. However, the electronic signal obtained in this way is very weak, and if it is directly connected to the speaker, it cannot be converted into sound waves at all. Only by amplifying these weak currents can the speakers be driven to achieve electro-acoustic conversion, and the equipment responsible for this work is the electro-acoustic guitar speaker.
Guitar Amplifier-Detailed Structure
Electric guitar speaker
Friends who have played electro-acoustic guitar must know that if there is no amplifier and speaker, then even the most expensive piano in the world is just a "dumb". For the electric guitar, the amplified speaker is not only its "mouthpiece", but also one of the mysteries of getting a good sound.
1. Pre-amplification and power amplification
General household high-fidelity speakers and amplifiers are separate, but in order to ensure the same sound and convenient transportation, the designer of the guitar amplifier usually bundles the amplifier part and the speaker, even if it is not in the same box, the designer does Mostly, the two will be fixed together by parts. The amplifier circuit built into the speaker is generally composed of two parts: pre-amplifier and power amplifier. The pre-amplifier performs shaping and amplifying of the weak signal output from the pickup circuit. It is often accompanied by tone (EQ) and distortion (Booster) circuits. It is one of the secrets of superb guitarists to make sound. The power amplification is responsible for amplifying the signal processed by the front-end circuit to a size sufficient to drive the loudspeaker to produce sound to achieve the final electro-acoustic conversion. Professional electric guitar speaker
2. Integrated and split
The so-called integrated speaker refers to the type in which the front stage, the power amplifier circuit and the speaker are installed in the same wooden or resin cabinet, which are generally sold on the market now. Split type refers to the type in which the circuit part and the speaker are installed separately. Because of the increase in the cost of the cabinet, it is generally a high-quality product. In recent years, in order to meet the requirements of musicians to obtain a variety of different tones, designers have made the preamplifier circuit into an external product separately, and used digital processing circuits to simulate the sound characteristics of various speakers, such as Line6POD speakers. Analog effects. With such an external preamplifier, if you want to get the sound of Marhill or Budweiser 5150 speakers in the studio, you don't need to find someone to move your speakers.
3. Electronic tubes, transistors, digital circuits
Inside the guitar amp
According to the different core components used, the amplifier circuit of the guitar speaker can be divided into three categories: the amplifier and the power amplifier circuit use the electronic tube (also known as the "bile duct") speaker, the sound is the warmest and simplest, and it is rock and roll. Beloved by blues musicians; speakers that use transistors are lighter than tubes, have a sharper tone, and have a longer lifespan; products that use digital amplification are not long after they come out, and generally have the advantages of low power consumption and clean sound. There are a variety of synthetic effects built-in. However, these three types of speakers are not completely separate. Designers often use the characteristics of these components to combine them. For example, some speakers use transistors in the front stage circuit, while the power amplifier circuit uses tubes; there are also types that use a digital processor (DSP) as the front stage, plus tube power amplification.
The guitar pickup signal amplified by the amplifier circuit is sent to the coil in the center of the speaker to generate a constantly changing magnetic field. This magnetic field interacts with the magnetic core of the speaker itself to push the cone of the speaker to move, and the resulting air vibration makes people I heard the sound. The speaker is the end of the entire electro-acoustic conversion, which has a great influence on the texture (harmonic) and volume (low frequency) of the sound. The size of the loudspeaker is usually expressed in inches. Products with a diameter between 8 and 15 inches are the most common. One inch is approximately 2.54 cm.
5. Backward open and closed
These two terms refer to the different structures of speaker enclosures. As the name suggests, the rear part facing away from the open speaker is open, while the cabinet of the closed speaker is fully enclosed. The former is most typical of Fender speakers, while the latter is one of the characteristics of Marshall speakers.
15W guitar speaker
6. Input and output interface
Depending on the specific model, the number and style of speaker input and output interfaces will vary, but generally one or two input interfaces (divided into high impedance and low impedance) and effector loop terminals (can be connected to external Effector), external speaker interface (connect to another speaker) and headphone output terminal. Generally, a large two-core unbalanced interface is used, and the models used in the studio also use XLR balanced output. When a wider sound pressure surface is needed, the external speaker interface comes in handy. You can connect another speaker speaker through this interface and a dedicated speaker cable. However, you should calculate the impedance value at this time, because when the speakers of two speakers are connected in parallel, the impedance value driven by the amplifier circuit will be reduced to one-half of the original value. If your speaker amplifier does not support such a low impedance, the sound will not be too good. On this issue, you can look at professional books on speakers. For a guitarist, that is also a very good "practice".
Although some different tones can be called up through the pre-amplifier, if you want to modify the tone in a wide range, you must use an external effector, usually a pedal guitar special effector of single block or digital synthesis. When connecting this type of effector in series, the effector loop terminal can be used, so that the degree of sound deterioration can be reduced on the premise of ensuring the original sound characteristics of the speaker as much as possible. The connection sequence is: loop send terminal (FxSend)-effector input terminal (Input)-effector output terminal (Output)-loop return terminal (FxReturn).
40W guitar speaker
In recent years, with the rise of home studios, guitar amps have also changed. Limited to the living environment, musicians often cannot use the microphone to pick up the sound of the speakers to record like in a recording studio. Therefore, the designer of the guitar amp drew a signal from the preamplifier circuit so that the guitarist could directly send this signal to the digital MTR (multi-track recorder), keeping the timbre characteristics of the amp (actually The timbre characteristics of the pre-stage circuit that has a greater impact on the sound).
7. The name of each part of the guitar speaker:
ch1 input ch1 controller ch2 input ch2 controller panel power indicator speaker dust cover roller side panel integrated speaker (front) power switch ST-BY switch effector loop terminal external speaker terminal rear panel tube speaker reverberation sound board Integrated speaker (rear) speaker amplifier speaker speaker split guitar speaker.
As you all know, the sound of classical guitars is good or bad. It depends on the sound quality of its resonance box, and the sound quality of the electric guitar depends on the sound quality of the speakers.
The electric guitar speaker is the sounding body of the electric guitar, and the electric guitar can only produce beautiful sound through the speaker, and the speaker is also a part of the musical instrument. This is very important for how to choose and use speakers. People who don't understand this often regard it as a normal speaker, and randomly insert an electric guitar into various audio equipment or ordinary amplifiers, thinking that it can produce a beautiful sound, and the result is disappointing. What's more, regardless of the fact that the characteristics of various instruments are different, one ordinary speaker is used for the entire band. There are many contradictions in the adjustment, and it is impossible to take care of one and lose the other. As a result, the sound effects are chaotic during the performance. Therefore, it is rare to share speakers at present, and choosing appropriate speakers for each is a prerequisite to ensure a successful performance.
Electric guitar speakers have the following differences from ordinary speakers:
1. Can be made tones
The electric guitar speaker is designed for the characteristics and performance requirements of electric guitars with multiple sound pulse components and large dynamic range. Ingenious processing of electric guitar acoustics through circuit technology, produces from clear and beautiful sound to full distortion and even whistling sound. At the same time, there are no other effects such as chorus and reverb. So as to meet the needs of various rock music performances, the electric guitar has modern electronic music sound.
For the convenience of the performance, in view of the particularity of the electric guitar speaker, it is designed into a machine-one box integrated form, with a portable structure. The speaker has the advantages of small size, light weight, high power, sturdiness, durability, stability, and reliability.
3. Open back
Since electric guitars need to produce a clear, bright, and broad city-like tone, the back is open. There are only a few cases. Examples are the YAMAHAHR series. This is just the opposite of ordinary speakers, Lin Diangusi speakers.
The tone control center frequency of an ordinary speaker is generally 100Q Hz, while the electric guitar speaker is reduced to between 500 and 250 Hz according to its characteristics, which makes the tone control effect very obvious.
5. High treble boost
The output of the first and third strings of most electric guitars is much lower than that of the fifth and sixth strings. Therefore, the electric guitar amp has a greater boost in the high range than ordinary speakers (up to 20 decibels), so that the pronunciation of the six strings is evenly balanced. b. Wide range of adaptation
In order to adapt to electric guitars with various output characteristics, dedicated electric guitar speakers are often divided into two input jacks, one for high impedance (only mH) and one for low impedance (LOW).
7. Convertible tones
In order to meet the needs of electric guitars to play various songs, there is often no foot switch to control various functions. For example, divided into two channels, according to the progress of the music, you can timely switch the "clear tone" or "distortion only" dual-band tone conversion or brightness switch, reverb, chorus, delay, etc.
8. Easy to operate
In order to facilitate the operation, the various control buttons of the electric guitar amp are located on the top or the top of the front, which is different from the normal speakers on the back. The scale of the control buttons is as eye-catching as possible. There are many different places, so I won't list them all here. Second, the purchase of electric guitar speakers The good sound makes people comfortable, and the unpleasant sound is annoying! Choosing a speaker with good sound quality will make your electric guitar performance more beautiful and give the audience a higher enjoyment. Electric guitar speakers are divided into two types: small bands and large professional bands. Some brands are divided into high-quality type and popular type. s portable chassis is integrated, the output power is mostly below 10o watts. The machine and the speaker can be separated from the structure. Several speakers can be stacked and used, which is suitable for large-scale performances. Its power is often more than 100 watts.
Guitar speaker-the difference from ordinary speakers
You may have heard the following two points before:
1. The guitar amp is the same as other amps in order to reproduce the original sound signal finely.
2. The guitarist always overloads the speakers to get enough volume.
Here we can say that the above two views are wrong, and we will explain the reasons before.
All guitar amps can be said to be a complete sound manufacturing process: the guitar itself, the preamplifier (including various effects, equalization, etc.), and the power amplification that can generate overload. Of course, the horn is an indispensable element. However, sound production and modification do not end with speakers. In fact, it is a cyclical process, that is, feedback. In general performance or recording, the volume of the speaker is above the middle and upper, and the volume generated by the speaker is enough to make the string resonate and add it to the note that is about to weaken, or generate acoustic feedback through other control technology equipment. But this feedback is not the annoying whistling sound we often hear on the microphone. For the guitar, when there is enough gain, it will produce natural overtones after the notes played. Regarding the use of feedback, there are corresponding guitar skills. I also want to ask a teacher in this regard. A higher gain is required when using feedback, but this does not mean that the volume is increased excessively. Therefore, the preamplifier/power amplifier circuit design of the guitar amplifier often produces a larger gain to overload it. This has the advantage of equalizing the volume of each string, playing and hitting/hooking/clicking the strings, and more Easy to produce overtones and so on. For those who are not musicians, it may be strange that the guitarist overloads the speakers, because they think it will produce distortion and make the sound quality worse. But in fact, in the past 30 years, people have racked their brains to create a variety of satisfying overload and distortion sounds, making it a technology. Nowadays, it is recognized that the more ordinary the distortion tone is, the better, and many guitarists are still looking for the "pure" distortion tone. Although there are many devices that imitate this kind of sound (effects, digital modules, power attenuators, etc.) at a low volume, the result is unsatisfactory. Nowadays, the sound of vacuum tube power amplification is still the object of many guitarists' desire.
Why should the speaker volume be as loud as possible?
Of course, if a guitarist just wants to play as loudly as possible, he can buy a transistor amplifier. At the current price, you can buy a 1600W transistor speaker with the money you buy a 30W vacuum tube speaker! And more durable. But what we want is sound! Not just the volume. In the case of using loudspeakers with higher power, it is impossible to lower the volume. This is frustrating news for those who do not want to disturb others, but also want to make the speakers make a beautiful sound. It is more difficult to describe this kind of distortion sound vividly. It is a bit like the sound of a harmonica, saxophone or violin, but it is completely unique to electric guitars.
In addition, the guitar itself also affects the overdrive timbre. A single pickup produces a bright, strong tone, and a double pickup produces a full, soft tone. Similarly, the speakers of guitar speakers are quite different from ordinary HIFI speakers. The speaker speaker modifies the sound to a certain extent, while the HIFI speaker only restores the sound accurately.
The HIFI speaker is designed to accurately restore the sound within the linear range, so beyond this range, the cone of the speaker may be damaged or even burn out the coil. The musical instrument speaker retains the linear part when it is close to higher power, and then limits the movement of the paper cone, so that the sound is compressed and a nonlinear part is generated. In addition, for the design of the musical instrument horn, at high power, it can still achieve burst notes without damaging the horn. Therefore, the horn of a musical instrument generally has a wide and short coil, and a smooth restriction on the movement of the paper cone under its conditions. Finally, the frequency response performance of musical instrument speakers and HIFI speakers are also different.