In fact, when Duan Yun was in school, he participated in the radio hobby group, and he did some production and research on speakers.

At the beginning, Duan Yun only knew a little about the production principle of sound, but fortunately, there were several music enthusiasts in the club, and Duan Yun also learned a lot about sound quality and music from them.

Later, with the cooperation of all the members of the club, Duan Yun and they hand-made a set of speakers with good performance, except for a small number of teachers in the school, all the rest were sold to college classmates, so that in the end, basically every dormitory in the school used the speaker equipment they modified and made.

Duan Yun still vaguely remembers the principles and methods of making this speaker back then.

In fact, if you want to make a high-level loudspeaker equipment, you must understand some basic theories of acoustics.

Generally speaking, the human ear is sensitive to mid-frequencies and insensitive to low- and high-frequencies, which requires a higher low-frequency and high-frequency component when reproducing musical sounds.

Secondly, the low frequency is non-directional, the medium frequency is more directional, and the high frequency is more directional. The positioning, direction, and surrounding of sound by the human ear are mostly in the middle and high frequency bands.

Then there is the application of SRS technology.

The so-called SRS technology is a general term for a series of world-famous audio patented technologies. SRS stands for SoundretrievalSystem, which means Sound Restoration System. The essence of SRS audio technology is based on the principle and mechanism of the spatial information in the sound signal perceived by the human ear, and the spatial information lost in the process of sound signal transmission (including compression and decoding) is extracted and restored, so as to reproduce the real surround sound for the listener, as if in the three-dimensional sound field of the scene, which is called "visible" sound.

Since the positioning, direction, and surround effect of sound by the human ear are mostly in the middle and high frequency bands, the application of SRS technology is based on the middle and high frequency bands. SRS technology is a frequency-shift and time-delay technique. Why can people hear a train coming and leaving? Because of the Doppler effect, the frequency of the sound of a moving sound source changes when it reaches our ears.

As for the technology in circuit design, Duan Yun also conducted repeated design and research with other team members in the interest group in his previous life.

The lower the frequency, the greater the energy content, and the higher the frequency, the smaller the energy content.

It is better to use a sub-stand effector circuit for low-frequency circuits to cope with the large dynamics of low-frequency energy.

In terms of circuit design, due to the existence of a broad spectrum and the large difference in energy corresponding to low frequency, medium frequency and high frequency, the audio in different frequency bands should be amplified separately, and different components and circuits should be used to reduce distortion. In fact, the DTS system is superior to the Dolby system in that the low frequency below 80Hz of each channel is separated and amplified, which greatly reduces the burden and distortion of the mid and high frequency surround power amplifier circuit, and reduces the cost.

Finally, in the choice of speakers,It is also very knowledgeable。

Because the low-frequency sound is easy to diffract interference and reduce the sound power, the low-frequency speaker should adopt a closed design, but considering the damping of the air flow on the low-frequency speaker, the exhaust hole should be made into a zigzag shape and add a flexible sound-absorbing material (i.e., a silencer tube. The ideal subwoofer speaker is to make a low-frequency resonance/resonance cavity in front of the paper cone, as if placing the horn at the bottom of the urn, and connect the silencer tube behind the paper cone, and minimize the volume of the silencing lumen to reduce resonance).

Or use the passive diaphragm to make a closed type, a simple inverted hole will lose low-frequency sound power, and the medium and high frequency due to the high frequency and short wavelength, is not easy to diffraction interference and easy to reflect, so the medium and high frequency speaker can be made into a reflective speaker and an inverted hole speaker, in order to improve the sound power and reduce replay distortion.

Crossover playback is also the key to speaker production, do not let the low-frequency and high-current flow into the medium and high frequency speakers, reduce distortion, and similarly, do not let the medium and high frequency current flow into the low-frequency speakers, reduce the loss of medium and high frequencies. Only crossover playback can achieve the effect of clear midrange, crisp treble, and powerful bass.

Although Duan Yun now has a complete design idea in his mind, with the current conditions of his workshop and the materials and equipment that can be bought at present, it is a little difficult to make the high-quality speakers that he handmade and DIY in college back then.

But considering the hot sales and commercial value of speaker equipment in recent years, it is still very worthy of Duanyun's technical reserves.

At present, Duan Yun is still mainly engaged in the production of TV antennas, but as he earns enough money by selling antennas, he can consider purchasing equipment through some special channels to expand his workshop.

Now Duan Yun Workshop can try to make one or two speaker samples, but this is still far from mass production, and Duan Yun still needs a lot of equipment and technology.

In addition, Duan Yun has established a sales network with a large number of 'high-quality consumers' by selling antennas and after-sales service, which has largely avoided the government's crackdown on speculation, which provides a strong channel for Duan Yun to sell various electronic products in the future.

Today is Monday, after Duan Yun made some improvements to the circuit drawings of the audio, he saw that it was almost half past seven, so he left the studio and rode his bicycle to the staff night school.

But before he could ride to the workers' club, he heard a woman's voice behind him.

"Duan Yun!"

Duan Yun looked back when he heard this, and found that Yu Shulan was riding a phoenix car and quickly chased after him.

"What a coincidence. Duan Yun also greeted with a smile.

"Where did you go on Sunday?" At this time, Yu Shulan's face showed a trace of displeasure, and then said: "Didn't we say last time that we would meet at the gate of the club at one o'clock in the afternoon to roller skate together......?

"Ah......" Duan Yun suddenly suddenly said with an apologetic face: "I forgot about this matter, I'm sorry, by the way, isn't Cheng Qingyan going with you?"

The last time Duan Yun sent Yu Shulan home, Duan Yun had said that if he had time, he would go to play together, but during this time, Duan Yun had been busy with the affairs of the Ma Junying workshop, so he forgot about it.

"You two are big liars!" Yu Shulan pouted slightly, and said angrily: "Cheng Qingyan is still at home drawing on Sundays, and you can't even see a shadow!

"Hahaha!" Duan Yun laughed when he heard this.

"You're still laughing!" Yu Shulan glared at Duan Yun and said, "I still regard the two of you as friends, but there is no reliable ......."

"Okay, you don't have to be angry, this Sunday, I'll bring a few more friends, let's go rollerblading in the city together, I'll cover all the tickets for eating and drinking, it's all right." Seeing Yu Shulan's angry face, Duan Yun immediately proposed.

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