[Basic knowledge of subwoofers] The principle and classification of how to connect subwoofers to subwoofers
First, the principle of subwoofers:
The internal power amplifier circuit of the subwoofer divides the sound into several frequency bands through the frequency divider. The output of the medium and high frequency band is to the satellite speaker, and the output of the low frequency band is to the subwoofer. Generally, the subwoofer emits a low frequency sound of 20-200HZ. , when the energy is not very strong, it is difficult for people to hear, and it is difficult to distinguish the direction of the sound source. Such low-frequency sound is transmitted through the reversing hole and resonates with the satellite speaker speakers. The low-frequency speakers and satellite speaker speakers produce weak sound. Combined with bass, the satellite speaker speaker will re-perform the speaker to release the bass, so the bass effect is very shocking, and it makes people feel like it is emitted from the satellite speaker speaker. You should basically understand the principle of the speaker by now. Low-frequency speakers and low-frequency resonant speakers should be understood with physical knowledge: satellites are weak bass that can be heard by people, and their waveform amplitude is small, that is, the energy is not large enough. When the ultra-low frequency generated by the speaker overlaps with it, due to After passing through the reversing hole, causing them to have the same phase, then the ultra-low frequency is loaded on the waveform of the satellite bass. Since the speaker has a very powerful power, the energy increases sharply after loading, which makes you feel very shocked.
Second, the types of subwoofers:
At present, the speakers of subwoofers can generally be divided into coaxial speakers, high-pitched speakers, super high-pitched speakers, and super-heavy bass. several categories. A coaxial speaker refers to a speaker with its own built-in power amplifier. It is not necessary to add another power amplifier when using it, and it usually has a cylindrical shape. The disadvantage of this kind of speaker is that the heat dissipation is not ideal and the power is not very large, and the cylindrical shape usually produces unnecessary resonance phenomenon, which reduces the controllability of the speaker. In contrast, an external power amplifier is required when the subwoofer works. The shape and power selection of this kind of speaker can be more flexible, and the effect is naturally more ideal.
Subwoofers seem to be the least likely to be used, often found around young people who like metallic music, and are a must-have for car owners who like pop and rock music. In principle, the subwoofer and the speaker work in exactly the same way, except that the diameter of the diaphragm is larger, generally 8 to 10 inches, and a speaker for resonance is added.
In terms of evaluation indicators, the subwoofer is basically the same as the speaker. The specific content will not be introduced here, but only the numerical requirements. The frequency response is generally below 200 Hz, and the rated impedance is also about 4Ω. , the sensitivity is generally greater than 90 dB/W/m.
Third, the material of the subwoofer:
The low-grade plastic speaker of the subwoofer has no sound quality due to its thin box and cannot overcome the resonance. The sound quality caused by the resonance of the box is reduced, and the sound quality is generally better than that of plastic speakers. Usually multimedia speakers are dual-unit two-way design, a smaller speaker is responsible for the output of the mid-high frequency, and the other larger speaker is responsible for the output of the mid-bass.
The material of these two speakers should be considered when selecting speakers: the tweeter of multimedia active speakers is now dominated by soft domes (in addition to titanium membrane domes for analog sound sources, etc.), which is closely related to digital The combination of sound sources can reduce the rigidity of high-frequency signals, giving people a soft, smooth and delicate feeling. Multimedia speakers are mostly soft domes such as silk film with better quality and PV film with lower cost. The bass unit determines the sound characteristics of the speaker. It is relatively important to choose. The most common ones are the following: paper cones, and there are several types of glued paper cones, paper-based wool cones, and compacted cones. The sound of paper cones Natural, cheap, good rigidity, light material and high sensitivity, the disadvantages are poor moisture resistance and difficult to control the consistency during manufacture, but paper cones are widely used in top HiFi systems, because the sound output is very average and the restoration is good. ; Bulletproof cloth, with wide frequency response and low distortion, is the first choice for those who love strong bass, but the disadvantages are high cost, complex production process, low sensitivity and poor light music effect; wool woven basin, soft texture, It has excellent performance for soft music and light music, but the bass effect is not good, and it lacks strength and shock; PP (polypropylene) basin, which is widely used in high-end speakers, has good consistency and low distortion, and its performance is remarkable Can be ordered. In addition, there are also fiber-type diaphragms and composite material diaphragms that are rarely used in popular speakers due to their high prices, so I won’t talk about them.
The loudspeaker size of the subwoofer is naturally the bigger the better. The large-diameter subwoofer can have better performance in the low frequency part, which can be selected in the purchase. Cabinets built with high-performance speakers mean lower transient distortion and better sound quality. The horns of ordinary multimedia speakers are mostly between 3 and 5 inches. Cabinets built with high-performance speakers also mean lower transient distortion and better sound quality.
Fourth, the structure of the subwoofer:
The speakers can be divided into bookshelf type and floor type in terms of structure, the former is small in size and clear in layers , The positioning is accurate, but the power is limited, and the extension and volume of the low frequency band are insufficient. It is suitable for music lovers who enjoy high-fidelity music, and is also the first choice for our multimedia enthusiasts; The sense of volume and elasticity is strong, and it is good at expressing the momentum and powerful shock, but if it is not done well, it will be slightly lacking in terms of layering and positioning.
5. How to connect the subwoofer:
1. The OUTPUT SUBWOOFER hole on the power amplifier outputs a low-level bass signal. That is to say, it can’t pick up the speakers. It needs to be equipped with an active subwoofer (subwoofer with power amplifier) to amplify the bass signal.
2. After having the active subwoofer, connect the “OUTPUT SUBWOOFER hole on the power amplifier” with the line input (LINE INPUT) on the active subwoofer with an RCA wire.
For lovers of different music, this is also an important content that should be understood before purchasing a subwoofer. Since PC users rarely have the conditions to place large floor boxes, small desktop bookshelf speakers should be the first choice for multimedia active speakers. In general: as long as the design of the power amplifier module is reasonable, the bigger the box, the bigger the speaker, the more pleasant the sound.
