Speaker unit for home theater set Speaker unit refers to the situation of speakers (commonly known as speakers) used in the set speaker of home theater. It usually refers to the size, shape and material of speakers, which mainly determine the characteristics of speakers.


Most of the structural forms of subwoofer are cone basin type, and a few are flat plate type. There are many kinds of subwoofer diaphragm, including aluminum alloy diaphragm, aluminum magnesium alloy diaphragm, ceramic diaphragm, carbon fiber diaphragm, bulletproof cloth diaphragm, glass fiber diaphragm, propylene diaphragm, paper diaphragm, etc. Bass unit, which determines the sound characteristics of the speaker, is relatively important to choose. The bass unit with aluminum alloy diaphragm and glass fiber diaphragm generally has small caliber and large bearing power, while the bass unit with reinforced paper basin and glass fiber diaphragm has accurate timbre and good overall balance when replaying music. The paper basin has natural sound, low cost, good rigidity, light material and high sensitivity. The disadvantages are poor moisture resistance and difficult to control the consistency during manufacturing. However, the paper basin is made everywhere in the top hifi system because the sound output is very average and the reducibility is good. Bulletproof cloth, with wide frequency response and low distortion, is the first choice for those who love strong bass. Its disadvantages are high cost, complex production process, low sensitivity and poor light music effect. The wool woven basin has a soft texture. It performs very well for soft music and light music, but the bass effect is poor and lacks strength and shock. PP (polypropylene) basin, which is widely popular in high-grade speakers, has good consistency, low distortion and commendable performance in all aspects. In addition, fiber diaphragm and composite diaphragm are rarely used in popular speakers due to their high price.
Generally speaking, as long as the frequency response curve of the mid-range loudspeaker is flat, the effective frequency response range is greater than the width of the playback frequency band it undertakes in the system, and the impedance is consistent with the sensitivity and low-frequency unit. Alto units generally have cone basin and ball top. But its size and power are larger than the tweeter and suitable for playing medium audio. The diaphragms of the Alto unit are mainly soft materials such as paper basin and silk film, and occasionally there are a small amount of alloy ball top diaphragms.
The function of high-frequency loudspeaker in speaker is to replay various high-frequency signals, and its working frequency is generally above 2K. The overall requirement for high-frequency loudspeaker is that it can have flat frequency response, high-frequency playback upper limit as much as possible and certain power bearing capacity to meet the requirements in the effective working frequency band. Its structural forms mainly include horn type, cone basin type, ball top type and aluminum belt type. At present, the most common domestic speaker and small monitoring speaker is ball top type. The ball top tweeter is divided into hard ball top and soft ball top from the material. The diaphragm materials of hard top treble include aluminum alloy, titanium alloy, magnesium alloy, titanium alloy composite film, glass film, diamond film and so on. The treble played back by the hard top treble unit has bright timbre and metal feeling. It is suitable for playing pop music, film music and effect music. The production of excellent aluminum alloy and titanium alloy composite film dome tweeter can also better express classical music and human voice. The vibrating film materials of the soft ball top tweeter are silk film, silk thread film, rubber film and bulletproof cloth film. The soft dome tweeter unit is flexible and relaxed when replaying music, and has good natural expressiveness. It is particularly handy when performing classical music, human voice and other music with standard listening concepts. In recent years, the playback upper limit frequency of silk film and silk film ball tenor has reached 40KHz. Theoretically, the upper limit frequency of tweeter unit should at least reach 20kHz, the higher the better. However, the unit with excellent high frequency upper limit is also more expensive.
Naturally, the larger the speaker size, the better. Large caliber bass speakers can perform better in the low-frequency part, which can be selected in the purchase. Most of the subwoofers in ordinary home cinemas are between 5 and 12 inches. The speakers made of high-performance speakers also mean lower transient distortion and better sound quality.

I have always liked the white light effect of the mechanical keyboard, which is more upscale than RGB (personal preference).


Dujia 620w first launched only the matte version, unexpectedly followed by a white version, and the shaft body has also become Kaihua TURBO customized shaft body. I have used the Dujia 620w white light version for a while, and now I am reposting an unboxing article.


Before describing the details of the keyboard, let me share the table set taken during this period of time when I was using the Duga 620w white light version.



Durga 620w with lighting effect turned on. I have used quite a few keyboards. The PBT keycaps of the Duga 620w white light version have a light-transmitting effect. This is the first time I have seen it. This is the most special feature of it in my opinion.



With the screen hanging lamp and the desktop with white light keyboard turned on, it looks very comfortable. The picture above is the scene where the screen hanging light is turned off.



The desktop scene with the screen hanging lamp and desk lamp turned on.



A keyboard, a mouse, a monitor, and other favorite gadgets, the desktop of a poor boy is as simple as that.



The last Durga keyboard was the Durga K310w purchased in the first half of last year. Compared with the K310w, the packaging box of the Durga 620w has obviously improved the grade.



· Keyboard body*1


· Replacement keycaps*3


· Puller*1


· Key puller*1


· Data cable*1


· Data line adapter*1


· manual


· Dust cover*1



Durga K620w has a total of 87 keys. If you like a small keyboard, you need to buy K610w (104 keys).



In terms of appearance, it is different from the design of ordinary keycaps. It is similar to hollowing out a whole piece of material to form a U disk, stuffing various parts, and digging out various key positions on the panel, and putting them into the shaft keycap.


The data port and power button are set on the right side of the back, which can basically be operated blindly with fingers.


Durga K620W achieves noise reduction and shock absorption effects through sandwich silicone pads and bottom noise reduction cotton.



The switch that Xiaogu started with chose the silent red switch. It is also the first experience for Kaihua TURBO to customize the switch. Dujia has gradually replaced the cherry switch with the domestic switch from the beginning, which shows that the domestic switch is getting more and more popular. He is popular and has a particularly outstanding side.


The keycaps are original height PBT keycaps, and the workmanship is very good. Keycaps are the direct medium for human-keyboard interaction, and a good keycap can greatly enhance the experience.



There are four LED displays on the right direction key, which respectively display upper and lower case/Bluetooth 1, key lock/Bluetooth 2, 2.4G mode, and battery power status.



The color of this keyboard is called "Fog Blue". The Dujia K620w matte version has only two colors (fog blue and dark green), while the white version currently only has the color of fog blue. The tofu block-shaped keycap matches the shape of the whole keycap, which is very beautiful in geometric lines. It is said that white is versatile, this keyboard with white main color is suitable for desktops of various shades and light colors.



Two-style foot supports can be set to three heights. This is based on personal preferences. I personally prefer not to open the feet, and I feel that typing is more comfortable.



The 2.4G transmitter storage compartment next to the left foot support.



This keyboard supports three connection modes, among which Bluetooth is version 5.0, with ultra-low latency, and its appearance, it is very suitable for building a wireless desktop. Support win/mac os dual system automatic identification, install the Zeus driver system, and customize the setting buttons.



Dujia 620W supports full-key hot-swapping (except for satellite switches) and full-key no-reverse in all modes. Most mechanical keyboards can only achieve full-key no-reverse only in wired mode.


Using this keyboard to code is easy to cause comfort. Durga 620W belongs to the hull structure, and the noise reduction effect is no worse than other gasket structure mechanical keyboards on the market. Friends who are familiar with Durga products will know that Durga keyboards generally have " "Mute red switch" this switch body, this time the Dujia 620W white light version is equipped with Kaihua's custom turbo mute red switch, the mute effect is very good.



Built-in rechargeable lithium battery. In terms of battery life, when the backlight is turned off, the Bluetooth mode can achieve about 360 days of battery life, and the 2.4G mode can achieve 200 days of battery life. Turning on the backlight depends on the specific brightness.



Yes, the white version of the K620 can adjust the brightness of the backlight, not only that, but also a variety of lighting modes to choose from, such as radar mode, wave mode, etc.


As an 87-key keyboard, Duga 620w white light version has all the functions that other wireless keyboards on the market should have, but its body is unique, can it also catch your eyes?

I have always liked Gundam, so when I saw this Gundam joint mechanical keyboard, you should be able to imagine my mood. I was really surprised and happy that finally, finally, I found my favorite keyboard.


In fact, I have heard of the brand ikbc before. I bought a solid-color mechanical keyboard from him a long time ago, and the impression is good. The red switch I bought at that time felt very good.


So later I saw that her family released this Gundam co-branded mechanical keyboard, and I bought this keyboard without hesitation. It cost more than 300 yuan. After I got it, I felt that this keyboard was worth it. This color scheme is really very classic. As for the feel of the keyboard, I think it should be placed in the second place. The feel must be good, and the price of more than 300 can already buy a good keyboard. I don't even want to throw away the protective cover, and I have to cover it when I don't use it.


When my roommates saw that I bought this keyboard, they all grinned. I am suddenly a little embarrassed to use this keyboard. I feel that although the color scheme is very good-looking, it seems to be too individual, so high-profile, hahaha.

I recently upgraded my computer desktop, mainly by installing a perforated board, so that some peripheral products can be hung on the wall, saving space on the desktop. By the way, I also want to equip the notebook with an external keyboard, because after using the mechanical keyboard of the desktop computer, I always feel that using the keyboard that comes with the notebook will make typing for a long time more tiring. So I saw some trendy keyboard brands, and when I was dazzled to choose, my friend recommended me Dujia’s Hi Keys mechanical keyboard. I was deeply attracted by this appearance. Today I will unbox it and share my experience.



This Durga Hi Keys mechanical keyboard has two colors, dark blue and silver white. I chose the dark blue color, and I was amazed at the first glance when I opened it. The real thing is so beautiful, it completely changed my perception of the keyboard.




The layout of the keyboard keys is different from the common 104 keys. The Hi Keys mechanical keyboard is small and exquisite, with an 84-key layout. Although it saves space, there are not a few commonly used keys, which is simple but not simple. The color matching of the buttons is also very special. The calm dark blue collides with the vibrant orange, showing an unruly and fashionable personality.





There are two kinds of tea shaft and red shaft on the shaft body. I chose the brown switch, which is the "universal switch" in the mechanical keyboard. It has the characteristics of a mechanical keyboard, and there is basically no sound when pressing the keys. It is very suitable for my typing and gaming needs. Both the tea switch and the red switch are very suitable for office and entertainment scenes.




In terms of hands-on experience, I have been used to using concave keycaps. The square keycaps of the Hi Keys mechanical keyboard are slightly raised, but the touch is round. Coupled with a tea shaft, after using it a few times to get used to it, the hand feel will feel better when knocking.



The common backlight of mechanical keyboards is also arranged. The Hi Keys mechanical keyboard is equipped with a minimalist white light effect, and a single light can also enhance the appearance, full of avant-garde technology. When the light is turned on, the keycap will show a soft white light effect, and there are 8 light effect modes that can be switched at will. When used at night, it not only illuminates the keyboard keys, but also creates a sense of desktop atmosphere.






In the actual experience of typing or gaming, it can bring a soft feel when pressing the keys. The sound of the brown switch is small, which is not much different from that of the red switch. It has the characteristics of noise reduction and does not affect others; The strength is very comfortable.




The keyboard supports 2.4G wireless + Bluetooth dual-mode connection, and the receiver is hidden in the storage box on the back. 2.4G wireless can ensure low latency in games. The switching method is also very interesting, using indium-plated toggle switches, which can quickly switch between the 3 devices. Compatible with windows, Mac, Android and IOS systems, it is convenient for me to use it on devices such as notebooks, computers and tablets.




The top row of buttons also has a wealth of shortcut settings. You can freely switch lighting effects, lighting brightness, playback switching, volume, etc. according to your preferences. The icons indicate that the operation with the Fn key is very simple and easy to understand.



The battery life is also a bright spot for me. The battery of the wireless keyboard that has been used for five years has long died, and now it can only be powered by plugging in the cable. Hi Keys mechanical keyboard can reach a maximum of 360 days of ultra-long battery life when the light effect is turned off, which is simply against the sky. When it is in 2.4g mode, it will be slightly reduced, and the game usage can reach 220 days, and you will gain a more enjoyable gaming experience. Even with the backlight turned on for a long time, it can last for a week. It can also be charged with the mainstream Type-C interface, and it takes three hours to fully charge, which is more intimate and convenient.



Finally, there are adjustable feet on the back and a non-slip rubber pad, which can adjust the angle of the keyboard according to the feel when using it. When the keyboard is placed on the table, it can also be kept stable without shaking.




In terms of comprehensive experience, whether it is in terms of design or the impact of color, this innovative keyboard really impresses me; I am also very satisfied with the comfort of use; and the long battery life is also very satisfying. very powerful. Whether it is office or entertainment, or a beauty party, it is a good choice. I also hope that Durga will bring me more surprises in the future!

written in front


It’s the day when the spring is warm and the flowers are blooming. For those who like spring, they are really looking forward to this flowering season. The only bad thing is that the days when the flowers are blooming are rainy, which undoubtedly increases the idea of ​​​​not wanting to go out. . So I continued to stay in my hut of a few square meters, tinkering with my favorite things. What I want to introduce today is also a small accessory related to spring. It can be regarded as responding to the theme of spring.









It is a keyboard: the AK992 three-mode mechanical keyboard from Heijue, with a color-matched Ode to Spring.









Keyboards are commonly used by everyone. Mechanical keyboards will have a different experience. Whether you are coding or playing games, or rarely use them, I think many people still want to have a mechanical keyboard. , Many customized out-of-print keyboards really make me greedy, but the wallet does not allow it. Of course, there are also many mass-produced keyboards, which look good and are very cost-effective. It is not bad to choose a favorite among these.









I found a green Crayon Shin-chan table mat that I bought last summer to match it. It matches the color of the keyboard very well, and there is a touch of yellow-green on the desktop with the title. For the table, it is really diverse. If you put in a little thought, you will have a different feeling. Although it can’t be as tall as what you see on the Internet, as long as you like it, you can even just change the table mat.









Well, let’s get into the whole and introduce this keyboard!


Black Jazz AK992


Let’s talk about the price first, because it’s really cheap, you can own a gasket structure keyboard for less than 300 yuan. Support bluetooth wireless wired three-mode connection, support full-key hot-swappable, three layers of built-in noise-cancelling cotton, double-stage foot support, more personalized volume knob, 99 keys with digital area, and adjustable RGB backlight . It can be said that it basically has the functions of the keyboard now, and it also has its own characteristics.
















The packaging of Heijue is actually the same. There are several replacement yellow keycaps on the accessories this time, which can replace the green ones, which is also a manifestation of the keyboard's personalization.









keycap


It can be seen that the color of this keyboard is mainly white and green or yellow, which is in line with the theme of spring colors, and it is also very suitable for calling it Ode to Spring. Pull out the keycap and you can see that the keycap is also made of two-color injection molding. The overall keycap material is PBT material, which is wear-resistant and does not oil, so you don’t have to worry about the keycap fading. Cap players are also very friendly.
















Shaft and structure


Of course, the switch body is a point of concern when using a mechanical keyboard. Different switches have different feel. This keyboard can choose three types of switches, green switches, red switches, and brown switches. It is a relatively conventional switch body, but it has satisfied most human needs. It supports full-key hot-swapping, so if you like other switches, you can of course change to other switches (three-legged and five-legged switches are fine). My own switch is a red switch, and I like red switches. rebound strength.




The structure is the very popular gasket gasket structure in the past two years. The PC positioning board is supported by setting silicone gaskets on the upper and lower covers, and the built-in three-layer sound-absorbing cotton (eva sandwich cotton + ixpe shaft pad + eva bottom cotton) , the overall keyboard has a certain deformation space when pressed down, and with the linear red axis, the hand feel is quite comfortable.









connection method


The three-mode connection is very convenient to realize wireless, and it is also convenient for the use of different devices, which is in line with the connection of many devices today. Of course, I personally prefer a wired connection, and it would be more comfortable to replace it with my own aviation plug-in cable. If you like wireless, 2.4G and Bluetooth connection are very good, the overall appearance is made of injection molding material, which has no effect on the signal, and the wireless transmission is stable.
















When it comes to wired connection and cable management, of course, we must also talk about the separate three-way outlet slot of this keyboard. This aspect is much simpler and cleaner for the arrangement of keyboard cables. The other is also such a connection card slot, interface It is not easy to fall off.
















RGB backlight


For RGB backlight, people who like it really like it very much. They will set their cabins to have an RGB atmosphere, of course, including the backlight of the keyboard, so this keyboard is also suitable for users who like RGB backlight. There are more than a dozen kinds of backlights. The mode can be changed at will, just choose the one you are comfortable with, and turn it off when you don't want to open it. It also supports functions such as custom color change in the driver.









The mechanical keyboard with three-mode connection must also consider the issue of battery life. This keyboard has a built-in 4000mAh capacity lithium battery, which can stand by for about 10 days in wireless mode. The power can be checked on the computer in Bluetooth mode. There will be a backlight flashing reminder when there is no power.









Summarize


Basically, this is the introduction of this keyboard. For me, I like its knob design, separate three-way outlet slot, and digital area. Of course, there are more functions at a good price. Since I spend a lot of time in my hut, it is not bad to arrange some themes that do not pass through the scenery at different times, such as a touch of spring green on the desktop this time. If you also like this three-mode If you have a mechanical keyboard, you can consider it.