The so-called mini projector is also called pico projector, TRT-Lcos Portable Projector. Mainly through the 3M LCOS RGB three-color projector and 720P film decoding technology, the traditional huge projector is refined, portable, miniaturized, entertaining and practical, making the projection technology closer to life and entertainment. best mini projectors under £100,mini projector pvo portable projector,mini projector portable,mini projector amazon,mini projectors for movies Shenzhen Happybate Trading Co.,LTD , https://www.happybateprojectors.com The factors affecting the low frequency and the extremely low frequency are mainly from the listening room itself and the position of the subwoofer in the space, and the low frequency sense of the subwoofer reproduction depends mainly on the shape of the room and the construction of the listening environment. Therefore, in different listening spaces, the reproduction of low frequency is also different, but the most important factor affecting the sound quality and volume is from the relative position of the subwoofer in space. There is a simple subwoofer placement rule, that is, when the subwoofer is closer to any wall or corner in the room, the amount of low frequency you can get is stronger; if you move the subwoofer away from these, then The bass energy you feel will also be reduced. But don't forget, the floor is also a major factor in reflecting the low frequency. To get the most sense of ultra low frequency, you have to place the subwoofer directly on the floor of the corner.
According to our past thousands of rooms, we tested the performance of countless subwoofers. Most of the cases have confirmed the best subwoofer position, not directly adjacent to the corner, or very close. All the tests we have done are the "Adaptive Window" technology using the "MLSSA" system, which is the only room testing technology that can be correlated with the time/frequency characteristics of the human ear system and sound.
Putting the subwoofer in the corner or near the corner is not only a good position, but also an excellent starting point for experimental testing. Usually, in such a positioning manner, the sense of low frequency in the space can be maximized, but in a few spaces, the quality of the bass playback is deteriorated, and the subwoofer is thus far away from the corner.
If you want to find a subwoofer in the listening room to find the smoothest frequency response, no peaks or dents, or no resonance, the most typical example is to place it in the closest listening position. On the corner. For example, if your sofa is in the back half of the room, then the most desirable ideal for subwoofers should be in the corners at the back.
In fact, the frequency curve measured by each listening space is not perfect, and more or less will cause peaks or dents due to the structure of the room. Therefore, you will hear a boom when the music is playing, and the sound will be blurred - not only the low frequency, but also the entire range will be affected. Therefore, our ultimate goal is to make the overall sound smooth and achieve high-quality ultra-low frequency performance.
How to make the subwoofer find the best place to live?
Here, we offer two effective ways to make your subwoofer find the perfect destination.
The premise of the first way:
We don't let heavy basses find home around the room.
First place the subwoofer in the position you listen to the most (Editing: the yellow emperor we often say), then connect it to your favorite system and let the whole system play the proper music. What you need to do next is to walk around the listening room, try to stay at every point in the space, and listen to the low-frequency performance of each position.
When you find that the entire system can satisfy you in all aspects, that is, your ears hear a smooth frequency response, a pleasant and impactful low-frequency performance, or the next best There is no bang in the position that makes you uncomfortable. Here, "probably" is the best place for your subwoofer to be in the listening room. Ok, now move your subwoofer to that point and walk back to your original listening position. If the sound performance at the Yellow Emperor is at this level, you can achieve the level you want, then the subwoofer. The best location should be finalized. If not, you have to repeat the above steps to return the subwoofer to the Yellow Emperor and continue to find the best placement.
The other way is more complicated, you must use the low frequency of the sound pressure meter and test (below 100Hz) (you can find it in the test software on the market). Try to move the subwoofer to every corner of the house, listen to the performance of the gradually decreasing low frequency band everywhere, and measure it with a sound pressure gauge, and plot the obtained values ​​on the paper; find the overall frequency The most slick of the graph is the best place to place the subwoofer.
Many advantages for subwoofer
If you are not limited by space or environment, we would recommend using two (or even more) subwoofers to match any sound system in the house. With the addition of the second subwoofer, not only can the overall system's low-frequency sense and dynamic range be greatly improved, but also the headroom of your home audio can be greatly increased; in addition, this extra subwoofer It is also able to double the diffusion amplitude of the ultra-low frequency (if the position is right), and increase the efficiency by as much as 3dB (relative to double the output power of the amplifier), that is, after using two subwoofers, it can be utilized. The remaining driving force of the power amplifier makes the total efficiency increase by 6dB.
The added meaning of the extra subwoofer is that the two subwoofers can easily increase the sound pressure by 6dB under normal working conditions, but save 25% of the power output for the rear stage amplifier; Also, because the working load of the subwoofer is reduced, the relative amplitude of the front and rear of the single unit becomes smaller, and the probability of occurrence of distortion is greatly eliminated.
You must be aware that the texture of the ultra-low frequency in a space, the peaks or sags on the frequency curve depend on the position of the subwoofer in this space. If your space allows the use of a subwoofer and find the most suitable position for it, use the double subwoofer in the same room to get the best results. This is also the best for double subwoofer. Placement method.
If you can't use the best placement method in your space, even if you divide the two subwoofers into two, they can match each other and achieve the best results. At this point, you have to set the options for the surround amplifier in different rooms, and still use the method mentioned above to listen and test the instrument to determine the best position of the two subwoofers, while using the same driving conditions. Control it.
Recently, we have often found that there are many problems from the use of "multiple subwoofers" on 5.1 channels with Dolby Digital/dts, and the main source of trouble is that users often ignore the 5.1 channel speakers. Surround expander and surround processor with low frequency output control (Bass Management). The low-frequency output control function allows the user to adjust the low-frequency output of each channel according to personal preference. That is to say, if only one subwoofer is used in the whole system, then this speaker has to be responsible for all the low-frequency sense of the whole system listening (including the low-frequency information of the left and right channels in the music); if we use The last two subwoofers, and each speaker can be responsible for the low-frequency output of all channels, of course, the playback benefits will be greatly improved, not to mention the use of more pairs of subwoofer.
Because of this, we strongly recommend that when using a subwoofer, it is best to input the low frequency part of each channel into the subwoofer instead of simply connecting the subwoofer to the LFE output.
Servo device and other forms of feedback
Many consumers have asked the subwoofer negative feedback. Although the earliest M&K Volkswoofer used a feedback line, this design was abandoned in the near future.
The servo line utilizes a sensor mounted on the unit to detect the reciprocating motion of the cone. As the monomer continuously moves back and forth, the generated signal is transmitted back to the power amplifier by the single coil, and the amplifier facilitates the use of the returned signal to compare with the original signal previously transmitted to the subwoofer. Any difference between the two means that distortion has been generated, and then the servo line will reverse the phase and transmit it to the input of the amplifier again, which theoretically offsets the original feedback. Unfortunately, if the input signal remains stable - such as a perfect sine wave, the feedback can be successfully detected; but this is not the case, because the music signal changes all the time, while the correction signal is transmitted back. The sound source has changed, and the sound has not improved, but it has made it worse.
Now we know that this is why the High End sound designer tried to minimize the feedback of the amplifier. Even with the perfect correction signal can greatly reduce the distortion, but the excessive correction signal is also the culprit in the manufacture of poor sound quality, which is the Transient Intermodulation Distortion we often hear. The same theory can be applied to the speakers, but the situation is even more serious. The reason is that the signal of correcting the movement of the horn is based on the motion of the single body, but the speed of conduction is not comparable to the flow of electrons close to the speed of light in the amplifier.
For the speaker, feedback is the killer of sound transparency and dynamic response. The sharpness and high output value generated by the reader force the designers to install the protection circuit on the amplifier. The sound quality also creates the turbidity and dynamic compression. .
M&K's philosophy is to pursue transient responses as much as possible, rather than playing back the perfection of a sine wave. Compared with other subwoofers that use bass servers, you can easily find out that M&K's products can express outstanding music with clear and detailed details, whether on the dynamic or transient. Various products.
Usually the projector has certain regulations on 2 aspects:
a). Size: Usually the size is the size of a mobile phone.
b). Battery life: It is required to have at least 1-2 hours or more of battery life when it is not connected to power.
In addition, its general weight will not exceed 0.2Kg, and some do not even need fan cooling or ultra-small silent fan cooling. It can be carried with you (it can be put into your pocket), and the screen can be projected to 40-50 inches or more.
Advantage:
1. Completely replace the MP5 player, video, listening to songs, playing games, e-books, picture browsing, etc. MP5 video is affected by physical performance, the screen can not be bigger, and the screen of this thing is at least 20 inches.
2. Instead of the TV function, the machine can have a built-in CMMB function, or it can be directly connected to the set-top box to play the TV, and it can be used as a 21-inch TV during the day.
Look, it can be used as a 60-100-inch TV at night to achieve the effect of home theater; it is convenient to move and break through the traditional film and television space. Even if you are on the mountain, you can also share today's TV series, movies, and MTV with your lover.
3. Business office: instead of large projectors, it is used for company meetings; the price of large projectors is 4,000 to 14,000, and the lamp life is more than 1,000 hours, which is not convenient to carry. 30,000 hours, no need to change the bulb for 3 years, easy to carry, the salesman only needs to bring a micro projector to demonstrate the new product, which can achieve the demonstration effect.
4. Teaching: training meetings, classroom teaching; traditional projectors are not easy to carry. In school classrooms, due to the naughty students, projectors are not safe to place in the classroom and are easily damaged by students. The portability of micro projectors makes up for the teaching vacancies. In the future, teachers only need to store the materials in the projector and show them to students for teaching, saving the trouble of textbooks and handwriting with pens and chalks.
In addition, the micro-projection has no radiation, which can fully protect pregnant women and people with myopia. Its low power consumption function is 1/1,000,000 of the power consumption of color TVs. One day of electricity has completely impacted the indicators of safety, environmental protection, health, etc., and has made amazing contributions to future social development, standing at the peak of the green world as a leader.