Don't play with big boxes, like Bluetooth speakers (mainly poor, and it is inconvenient to rent a big box by yourself), so let's talk a little bit from the side of Bluetooth speakers.
A speaker is not just a box and a speaker to make a good sound. Although I have always disliked that changing the cable or even changing the foot pad can improve the vocal quality, there are some basic things about the speaker that everyone agrees with. I think there are the following 4 points.
1. Compared with the speaker unit, for speakers, the more important thing is the cabinet design. If the cabinet is designed well, it can often produce unexpected effects. The most popular example is that Bose speakers tend to have small volume and large energy. Well-known, if you look at the dismantling of his speakers, you will know how complicated it is. A big kettle on hand, with a two-pound thing, produces a very shocking bass, and the Miaoyun series, which is higher in size, is still compact. But the energy is much greater. The scientific principles involved here cannot be designed without deep theoretical knowledge.
Second, the material of the speaker, the density of the material, the rigidity, etc., actually have a speaker for the speaker, of course, after the quality reaches a certain stage, this effect will become very small.
Third, the speaker unit, this involves more factors. Generally speaking, according to different styles, some parameters of the speaker will change a lot. The most ideal speaker is that the diaphragm is rigid enough and light enough, and the damping is small enough. But this material is still relatively expensive at this stage. Therefore, if a loudspeaker requires good low-frequency quality, then the rigidity of the diaphragm must be good enough, but then the quality of the diaphragm will rise, and the inertia will also increase, which is often detrimental to high-frequency, here is such a case Let's give an example. Some models of presonus monitor speakers I know are made of Kevlar for the mid-low frequency unit, which is light and strong, but the durability is worrying.
Fourth, parameter matching, here usually refers to active speakers. We know that the frequency response of each type of speaker is definitely different. At this time, it is necessary to make a fuss on the circuit or audio processing, so that when the final circuit is matched with the speaker, the frequency response of the entire system can be close to normal or meet the manufacturer's adjustment. Tone style. If you have a passive speaker, because you don't know what power amplifier you will use, you can only use the speaker with the cabinet design to make the frequency response of the entire speaker close to the ideal state.
Therefore, it is not easy to design a speaker to make it. Of course, a speaker must be a high-priced electrical appliance. After all, this thing can only be used for many years, and most people really only need to listen to it.
In addition, don’t believe in how awesome and good your self-made speakers are, especially active ones. Out of self-control plots, those people can account for 70% of their brains, and use those MSG discs to fool people all day long. Unless he is really proficient in the electrical characteristics of various digital-electrical analog-electric devices, and also familiar with vocal physics how to calculate and simulate tests, and also signal processing to burn code to dsp. Otherwise, how much is the phase deviation of a capacitor connected to the sine wave, and you don't know how many turns of the box of the labyrinth box, how long and how big the cross-sectional area of each channel, and what kind of characteristics the matching speaker needs. No matter how good the speaker amplifier circuit is, it is just a pile of rubbish.