The speaker is basically composed of three parts: speaker, crossover, and cabinet. According to the number of speakers, it is divided into two units, three units...
There is also a type that integrates the tweeter and the woofer, called a coaxial unit, which is one unit from the outside, but in fact it is still a two unit.
The frequency divider, as the name suggests, divides the frequency band of the audible sound [20-20000Hz] into several frequency bands and sends them to the corresponding speaker units. According to the division of frequency bands, the two-band divided into high and low-frequency bands are called two-way frequency divided into high, medium, and low-frequency bands called three-way frequency, and so on.
The box body is generally made of logs or medium density boards, and is divided into closed boxes according to the box structure [without inverting holes, the air inside the box is insulated from the outside], and inverted boxes [with inverting holes]. There are also some less common box structures: labyrinth type, exponential type, negative resistance type, horn type, etc.
According to the scope of use of speakers, they are divided into: professional boxes [used for sound reinforcement in performances, halls, halls, venues, and halls]
Monitoring box [professional monitoring for various recording agencies] civilian box.
According to the way the speakers are placed, they are divided into bookshelf boxes and floor boxes. The bookshelf boxes are mostly two-unit, two-way structure, and are mostly used in rooms less than 20 square meters. The floor box is mostly multi-unit, multi-frequency structure. Use more than 20 square meters.
The performance index of the speaker:
General speakers are marked with many of his application parameters, the most common ones are:
Power: Generally measured in W or VA, the common one is nominal power [rated power, non-distortion power] refers to the maximum input power under the condition that the nonlinear distortion does not exceed the standard range of the speaker. It is the normal working power of the speaker, and it will not be damaged if it works continuously for a long time.
Sensitivity: His definition is the sound pressure generated at a distance of one meter from the reference point when a pink noise voltage of 1 watt is applied to the speaker. Expressed in decibels [db]. The higher the sensitivity of the speaker, the louder it is under the same driving power, which is very important when using a low-power amplifier.
Impedance: It refers to the pure impedance presented by the speaker when the audio signal is added to the input end of the speaker. The common ones are 4 ohms and 8 ohms, and there are also 3 ohms and 5 ohms systems abroad. Pay attention to match with the output impedance of the power amplifier when using it. Especially the matching of the amplifier to the speaker impedance is particularly important.
Its definition is difficult to explain in a few words. Generally, it refers to the frequency reproduction range of the speaker when the high and low ends of the audio range drop by minus 3 db. Naturally, the wider the better, the current HI-FI speakers can achieve 20000HZ or even 30000HZ playback at the high frequency end. It is not a problem to achieve 20HZ due to the limitation of the speaker diameter and the volume of the cabinet in the low frequency range. Not easy, the low frequency range of general bookshelf speakers is even worse.
Now I have some knowledge of speakers. To be honest, it is very simple, but it is extremely difficult to do well. For beginners, it is not difficult to make a pair of entry-level HI-FI speakers by themselves after mastering a certain basic speaker knowledge. Especially nowadays, some merchants have launched many speaker kits. As long as you install them carefully according to the production drawings, the success rate is extremely high. And because these kits have been carefully designed and matched by the manufacturer, the sound quality and effect are guaranteed. And its cost is only one-half to one-fourth of the finished product. Compared with the imported speakers with a set of units, the speakers made by the author with the Gentleman Bao’s 8545K unit have been evaluated by many senior enthusiasts. The sound effect is by no means lower than that of foreign products, and the cost is only more than three thousand yuan, only four of the imported ones. One part.
Don't make speakers, buy a few units and frequency dividers, buy a finished cabinet and install it on top. The speakers made in this way are definitely not good. Moreover, there are too many fake and shoddy products on the market, and the quality cannot be guaranteed. The safer way is to mail-order complete sets from some reputable sales units. If you have good woodworking skills, you can build the cabinet yourself according to the recommended drawings, or you can ask a carpenter to do it for you, as long as the cabinet volume matches the recommended volume of the woofer.
Little knowledge of hanging speakers:
The suspension sound diffusion will be more average than on the flat ground, we know that at this time: sound pressure = 20LOg (reference distance / distance), that is, SPL = 20LOg (Dref/D)
If the distance from the speaker is doubled, the sound pressure will decrease by 6db (inverse square law), because SPL=20LOg(1/2)=20LOg0.5=20*(-0.301)=-6db
Suspended speakers have their advantages, but if you plan to hang speakers, please pay attention to hiring a professional consultant, because this is a matter of life. Note that the suspension system should calculate the endurance at the weakest connection part. When installing the suspension speaker system, you must know the endurance of the suspension accessories you use. During the installation process, pay attention to some specific issues, such as the power distribution on the sling. At this time, the internal angle sine value = negative angle efficiency (Load Angle Efficiency). Keep the internal angle to a minimum and not too flat, which will reduce the bearing capacity of the sling.