Purchasing Tips: Preliminary understanding of speakers before auditioning. For the initial understanding of a pair of speakers, you can use the steps of "observation, weighing, knocking, and identifying" to identify them: first, observe the craftsmanship, second, weigh the weight, and third Knock on the box and look for the nameplate. One look at the craftsmanship is to judge the quality and quality from the first appearance of the speaker: speakers made of natural logs are of course the best. There are many sky-high-priced world-famous supreme speakers, including Italy’s Chario, Guarneri Homage (famous piano), etc. However, due to factors such as environmental protection, lack of resources, difficult processing technology, and long time, such good boxes will never be as popular as the ubiquitous "Rejoice" shampoo, and the price will certainly not be low. Therefore, common speakers are made of MDF medium density fiberboard with a thin layer of veneer on the surface for decoration: speakers with real veneer and fine exterior decoration, especially those with rosewood, bird's eye, rosewood, walnut, nan, red oak Such as rare wood veneer, its natural wood grain visual effect is excellent, and it feels smooth and comfortable. Especially those with symmetrical butterfly pattern real wood veneer and multi-layer coating and polished piano lacquer. Most of them can be regarded as mid-to-high-end high-quality speakers, and there are very few counterfeit products. Boxes covered with PVC (Sapele) plastic are popular goods. Although they are finely made, they can only be considered mid- to low-end goods at best. Although the box decorated with this textured paper veneer looks very good, you should pay more attention to whether the veneer seams on the back of the box and the excavation process of the speaker installation position are accurate. Fake and shoddy products generally do not pay attention to these details, so you can make a correct judgment with a little care. The second is to consider the weight: most good speakers are made of high-quality MDF particle boards of 18 to 25mm, and high-end flagship speakers are made of overweight solid wood such as rosewood and yellow pomelo or multi-layer composite plywood, so the weight is very shocking. Often the net weight of a pair of speakers reaches fifty or sixty kilograms. Most of the mid- to low-end mass-produced goods are made of soft particle board, while counterfeit and shoddy products are often made of low-quality paper and plastic boards, so they are generally lighter in weight. There is often a saying in the audio industry that "experts look at quality and laymen weigh weight." Heavy speakers are definitely better than light speakers. But be wary of unscrupulous merchants who fill the bottom of the sound body with sand, gravel and cement to increase the weight to deceive consumers. The third is to knock the box: Use your knuckles to knock the upper, lower, left, right and front baffles of the box. All sides of the box will make a solid and slight crisp sound. It feels like the board material is hard and thick, and there are many reinforcing ribs inside to support it. The structure of the box Reasonable and strong, it has a variety of sound insulation and standing wave prevention measures. The processing cost and difficulty of this kind of box are high, so there are few fake and shoddy products. If you tap the box with your knuckles and it makes a "pop, pop" sound, it means that the board is too thin, the material quality is too poor, and the structure is unreasonable. There is no sound-absorbing material or reinforcement inside, resulting in a large amount of diffuse reflection and standing waves in the box. It is absolutely impossible to get a good playback effect by purchasing this kind of speaker. The fourth is to recognize the nameplate: Really good speakers have a well-made gold-plated or chrome-plated nameplate mark. The nameplate usually has a distinctive trademark, company, name, place of origin, corresponding indicators, etc. engraved on it. Imported boxes have English words such as: Made in xxx or Manufacture and corresponding trademarks, speaker specifications, etc. If there is only Designin... (XX design) or only a country name is marked vaguely, or even except for a few simple and extremely loose basic indicators, neither the place of origin nor the manufacturer can be seen, and the trademark has no registered mark. . Most of these three-no products are suspected of being counterfeit and shoddy. Famous brand speakers attach great importance to brand image and corporate visibility, so the nameplate markings are very standardized and exquisite, with all indicators, company names, and origins available. Some nameplates are even made of thin metal plated with 24K real gold, and the fonts on them are concave and convex. The product not only has the date of manufacture, but also has the production serial number, and even the pairing serial number and the ID card that came with the box. For this type of speakers, as long as the price is reasonable, you can generally choose them with confidence. Judging the quality of the speaker from the technical indicators As mentioned above, there is usually a technical label on the back of the finished speaker: the content is nothing more than the frequency range, sensitivity, power carrying capacity and impedance of the speaker. Among them, sensitivity is the most important indicator of a speaker, which to a large extent determines what kind of power amplifier the speaker should be equipped with, how much power is needed to push it, and so on.

The sensitivity of most listening-grade home speakers is between 86-92dB. For the same power amplifier, at the same volume (for example, the volume is turned to 10 o'clock), the higher the sensitivity, the louder the sound. The power requirements and requirements of the power amplifier will be lower. This is what people often say: this pair of speakers is easier to recommend. The sensitivity of professional speakers used in many commercial OK halls exceeds 100dB. No wonder many people feel that the sound is very beautiful when they go to OK halls to sing karaoke, and they can achieve a high volume effortlessly. But you must not think that the higher the sensitivity, the better. In fact, speakers with a sensitivity of more than 92dB are made of metal cones, PP cones, etc. that have relatively light and thin cones, which will cause the control of the speaker to be impaired, thus As a result, the sound quality is thin, beautiful, exaggerated, and tough, and lacks many details and charm of music. Not very suitable for HI-FI listening use. Many famous brand-name speakers with thick, soft and musical sounds usually have relatively low sensitivity. For example, the sensitivity of top speakers such as British ATC, Italian Famous Instruments, and Zhuoli is only 82dB. This type of speaker is often extremely difficult to maintain. It requires a huge power amplifier with a huge output current to make it work in the ideal linear region, and the cost is by no means small. Another most important indicator is frequency range. For example, the frequency range of the domestic high-quality Xindak Compass No. 1 bookshelf box is 60Hz ~ 20KHz ± 2.5dB. 60Hz represents the extension value of the speaker in the low-frequency direction. The lower the number, the better the speaker's low-frequency response: 20KHz represents the high-frequency extension the speaker can achieve. The higher the number, the better the audio characteristics. The suffix ±2.5dB indicates the degree of distortion in the above frequency range. The smaller the distortion, the flatter the frequency response curve will be. The distortion level marked by some speakers is ±3dB, and its frequency range should become wider. Some speakers do not indicate this indicator, and the frequency extension range will become very wide. For example, if the Compass No. 1 box mentioned above does not indicate that the distortion is controlled within a range of plus or minus 2.5 decibels, the frequency range can be marked as 40Hz ~ 23KHz. It should be pointed out that it is meaningless not to label the frequency range of distortion. If the manufacturer knowingly commits the crime, it can only be suspected of having bad intentions and intentionally deceiving consumers. It also means that the specifications of the speaker are not standardized, and the manufacturer lacks confidence in its products, making it difficult for people to buy with confidence. Carrying power is a reference indicator for speakers. It is expressed in watts. This indicator does not indicate the quality of the speaker. It only provides a reference for selecting a power amplifier: for example, the carrying power of a pair of speakers is marked as 10 to 200W. , that is to say, the power amplifier required to drive the speaker must have an output power of at least 10W, but avoid using an amplifier greater than 200W for full power output. Otherwise, there may be concerns about burning the box. Generally speaking, there is no need to worry about whether a home speaker can be pushed or not. There are only questions about whether it is good or not, and whether it is good or bad. A carrying power of less than 200 watts is more than enough for ordinary households. Do not deliberately pursue too high a level. . Another indicator of speakers is the impedance value, which is generally 8Ω as its nominal value. The impedance value of most two-way bookshelf boxes is 8Ω. Multi-unit and multi-frequency floor-standing speakers also have 6Ω and 4Ω. The smaller the impedance value, the greater the current that needs to be driven, and the required power amplifier power is correspondingly higher. In the author's opinion, it is best to choose 8Ω impedance speakers for home use, which are better matched with power amplifiers. Identification of subwoofer speakers The quality of subwoofer speakers directly determines the frequency response range of the speakers and the quality of the bass effect. From the perspective of speaker cone design, there are currently "dialysis paper cones", "glued paper cones", "bulletproof material woven cones", "wool woven cones" and "CD film" on the market. The advantage of "dialysis paper cone" is low cost, but the disadvantage is that the bass sounds dull when the power is too high, and the durability is poor; "glued paper cone" also has the advantage of low price, slightly better durability, but is also not suitable For high-power use; these two types of products are fine for general enthusiasts, but definitely not professional enough.

④ Pay attention to whether the impedance of the speaker is suitable for the recommended value of the amplifier. ⑤ Do not use it beyond the rated power. Otherwise the sound quality will deteriorate or even damage the speaker. ⑥The outer shell should be wiped with soft, dry cotton cloth. Do not apply furniture wax or benzene or alcohol substances. ⑦The dust on the surface of the speaker can only be removed with a soft brush, not a vacuum cleaner. ⑧The speakers should be placed on a solid, sturdy floor to avoid bass attenuation. Don't place the speakers too close to the wall. ⑨Do not place the speaker too close to the record player to avoid acoustic feedback and howling. ⑩If there is a medium and treble level adjustment, you can adjust it according to your listening requirements until the sound is satisfactory. Edit this paragraph speaker system failure analysis The speaker system is one of the important components of audio equipment. It usually consists of speakers, crossovers, cabinets, sound-absorbing materials, etc. The speaker system has a low failure rate and fewer types of failures. Common failures include the following four categories. Silent 1. The speaker wiring is broken or the frequency divider is abnormal. After the speaker wiring is broken, the speaker unit has no excitation voltage, which will cause a silent failure. Frequency dividers are generally not easy to break, but faults such as desoldering of lead joints and short circuit of the frequency dividing capacitor may occur. 2. The voice coil is broken. Use the R×1 scale of the multimeter to measure the speaker lead-out solder tab. If the resistance is ∞, use a knife to scrape off the sealing paint on the leads at both ends of the voice coil to expose the bare copper wire and then measure again. If there is still no connection, it means that there is a problem inside the voice coil. The wire is broken; if the measurement is successful and there is a "click" sound, it means that the voice coil lead is broken. You can solder the wire, and then use another piece of enameled wire that is similar to the voice coil winding to solder it properly. 3． Speaker wire is broken. Due to the frequent vibration of the speaker cone, the braided wire is easy to break. Sometimes the wire is broken, but the cotton core wire remains connected. This kind of braided wire is not easy to buy and can be replaced by a slightly longer flexible wire. 4. The voice coil is burned out. Use the R×1 scale of the multimeter to measure the speaker lead. If the resistance is close to 0Ω and there is no "click" sound, it means the voice coil is burned out. Before replacing the voice coil, you should first clear the debris in the magnetic gap, then carefully put the new voice coil into the magnetic gap, straighten the voice coil, and use strong glue to fix the upper and lower positions of the voice coil while listening, until the voice coil is in the best position. After positioning, use strong glue to fill the gap between the voice coil and the paper cone to about half, and finally seal the dust cover, put the speaker cone upward, and leave it for one day before normal use. The sound is sometimes non-existent 1. The speaker lead is defective. It is usually caused by moldy breakage of the voice coil lead or poor welding. When the paper cone vibrates frequently, the breakpoint is sometimes connected and sometimes disconnected, resulting in irregular sounding and non-ringing faults. 2. The voice coil lead is broken or about to be short-circuited. 3． The power amplifier output jack has poor contact or the speaker input wire is disconnected. 1． The speaker performance is poor and the magnetism of the magnet decreases. The sensitivity of the speaker mainly depends on the magnetism of the permanent magnet, the quality of the paper cone and the quality of the assembly process. A ferromagnetic object can be used to touch the magnet, and the magnetic strength of the magnet can be roughly estimated based on the size of the attraction. If the magnetism is too weak, the speaker can only be replaced. 2. The magnetic core column is loose. When the magnetic core pillar of the speaker is loose, it will be attracted to one side by the magnetic plate, causing the voice coil to be squeezed and hindering normal sound production. During maintenance, you can press the paper cone lightly with your hands. If it cannot be pressed, the voice coil may be pressed by the core column, and it needs to be disassembled and re-glued before it can be used again. 3． The frequency divider is abnormal. When there is a defective component in the crossover, the signal in the corresponding frequency band is blocked, and the speaker in that frequency band has a small volume failure. You should focus on checking whether the crossover capacitor in parallel with the woofer is short-circuited, and whether the crossover inductor coil in parallel with the tweeter is short-circuited between layers.