First, the audio system installation and debugging method
The audio system is a very important part of the home theater, in addition to good visual effects , sound surround and accurate sound image positioning is the most important thing, therefore, how to install and configure the home theater sound system becomes particularly important. In the process of setting up a home theater, after choosing the speakers that suit you, the next job is to place, install, and debug the speakers. Since the home theater system has a set of strict specifications in the installation, placement and debugging of speakers, it means that users can only get the ideal sound by following these specifications to install and debug the speakers.
1. Installation of front channel speakers
The front channel consists of two main speakers and a center speaker, referred to as LCR channel. These three speakers are responsible for most of the sound in the software. Therefore, it is very important during installation. According to THX’s example, the best way to install LCR speakers is to install all three speakers at the same height and at the ear level of the listener when sitting, so as to obtain the best sound field and correct vocal dialogue positioning . However, this is not necessarily the case for the home environment of the vast majority of consumers. For example, consumers who do not use sound-transmitting screens or who use televisions cannot install them as described above. For this part of consumers, you can try to install the center speaker on the upper or lower edge of the display device, and then adjust the radiation direction of the speaker. However, there is one thing that must be noted in this approach, that is, the angle between the installation height of the center speaker and the L and channel-only speakers cannot be too large by 10 degrees, so as not to damage the sound image positioning and sound field of the vocal dialogue.
In addition to the above installation methods, users can also try to install the LCR channel speakers on the upper or lower edge of the display device at the same time. Then, make the same adjustment to the radiation directions of the three speakers, so that an ideal front sound field can also be obtained.
2. Installation of Surround Speakers
The currently available surround speakers include dipole radiation speakers and traditional direct radiation speakers. For the current 7.1 channel AV system, 4 surround speakers are required. In general, 4 dipole radiating speakers or 4 direct radiating speakers can be configured, or dipole speakers can be used for side channels, and direct radiating speakers are used for rear channels. There are also some specific requirements for these speakers to be installed. For example, direct radiation speakers point the radiation direction to the listening position like the front LCR channel, and for dipole speakers, you need to point the “zero zone” of the speaker to the listening position. In terms of the installation height of the speaker, according to the example of THX, the installation height is about 1.8m-2.2m, then consumers need to use the speaker bracket to fix the speaker on the wall. Therefore, consumers can go to the shop selling racks in the electrical city to buy some suitable speaker brackets to install the speakers. If you can’t find a suitable bracket, you can consider customizing one according to your own speakers, but the cost will be relatively high. However, at present, some speaker manufacturers will launch corresponding speaker brackets according to their products when producing speakers, so as to facilitate consumers to purchase and use. For example, M&K, Genelec and other professional manufacturers have launched corresponding speaker accessories.
3. Setting and placement of subwoofer speakers
The subwoofer speakers are mainly used to make up for the lack of low frequency lower limit of the main speakers. , it can also play a role in increasing the low frequency energy. Therefore, consumers must set the low frequency crossover point of the AV amplifier before use. When setting the crossover point, it should be set according to the speakers you choose. For example, if you choose a home theater speaker with THX certification such as M&K, Atlanta, etc., then you can set all the crossover points at 80Hz. As with other speakers, you have to set the crossover point of each channel according to the low frequency response of each speaker. After the crossover point is set, the subwoofer can be positioned. So where is the best place to place the subwoofer in the room? Since the low frequency below 80Hz is almost non-directional, in theory, the subwoofer can be placed anywhere in the room at will. But in fact, consumers need to try to listen to the subwoofer in different positions in the room to find the best placement point. Under normal circumstances, consumers can place the subwoofer in the front.
4. General debugging of the speaker system
Finally, let’s talk about the overall debugging of the speaker system. First measure the distance between each speaker and the human ear (generally the distance between the tweeter and the human ear), and input the measured distance value into the AV amplifier. Then consumers use a sound pressure meter at the listening position to measure the output sound pressure of each channel, and independently adjust the output level of each channel in the AV amplifier according to the reading, so that the sound pressure of each channel reaches 80dB reference sound pressure value. Then the speaker setup is basically complete.
After completing the above two steps, it can be considered that the basic debugging has been completed for the ordinary consumers of Dajiafen. However, for some consumers who pursue better results, it is recommended to use an equalizer to correct the frequency response curve of the room. Why is it so open? Mainly because the frequency response curve of the listening environment of most consumers is not ideal. Of course, some people think that adding an additional equalizer will affect the sound quality, but if the frequency response curve of the room is not ideal, it will seriously affect the overall sound balance, and finally lead to the deterioration of the overall sound effect. Therefore, in a relatively unsatisfactory listening environment, using an equalizer is a good choice.
Before using an equalizer, the first condition is to understand the frequency response curve of your room. At this time, you can find a friend who is engaged in acoustic measurement to help you measure the frequency response curve of the room. Then, make corresponding attenuation or gain on the equalizer according to the room frequency response curve. However, it should be noted that when adjusting the equalizer, it should not be too flattened. This is because adjusting the gain of the corresponding frequency band in the equalizer actually increases the output level of a certain frequency. If too much gain is adjusted for a certain frequency, the amplifier will be caused by the excessive level given by the front end. Burn out, so be careful when adjusting.
Second, the connection method of the audio system
Since the general home theater X.1 speakers are passive, they are all powered by the power amplifier. The speaker unit is driven, so in addition to selecting the appropriate power amplifier, the selection of audio cables is also particularly important. Only by ensuring that the road is smooth and smooth without interference can the quality of the transmitted signal be ensured. Now there are many optional wire brands on the market, such as foreign superspace, Xiansheng, Zhigao, Yabao, etc. Domestic Huamin is also good, and try to choose the smaller the DC resistance, the better, the higher the degree of pure copper, the better Good and preferably larger than 2.5 square wire, the brand’s finished wire and loose wire are optional and not difficult to make. Wire investment should be moderate, and the investment ratio should generally not exceed 20% of the total audio volume.
General audio connection method
Video output device (Blu-ray player, DVD player, HD player, HTPC) → HDMI cable or optical fiber (same as axis)→Amplifier→Speaker/Subwoofer.
The connection is only the foundation of the home theater system. Being able to make sound and see the picture is half the success. How to debug and how to deal with the simple indoor audition structure in the later stage is also a very important part.
III. Requirements for placement of X.1 speakers
The placement of main speakers and surrounds requires multiple auditions or the use of professional equipment. The best effect, but the general family experience and equipment are limited, but we can also achieve better audio-visual effects through some simple methods. First, the two main speakers must be on the same level, and generally excellent speakers do not need to face each other. The listener only needs to be placed in parallel, and the listener should ensure a better stereo effect in the superimposed area of the two speakers. Surrounding is also an indispensable part of building a home theater system. The 5.1 or even 7.1 THX standard requires higher requirements for surround. Since the surround speakers are generally bookshelf boxes, if the surround is supported by brackets, the height of the speakers is generally slightly lower. It is higher than the height of the listener’s ears when they sit down. If it is mounted on the wall, the angle of the surround can be adjusted appropriately, and the directivity can be matched to achieve the best surround effect. In the X.1 system, the center mainly plays the function of audio playback such as movie dialogue. It is recommended to place it below the TV or projector, and the angle is slightly raised. A central placement behind the curtain would be the best option.
Four. Subwoofer placement and debugging
The subwoofer is a particularly important aspect of the home theater system. For low-frequency sound, the directivity of the sound is poor, so the placement requirements for the subwoofer are low. However, since it mainly works at low frequencies, it is recommended to place the subwoofer on the floor of marble or ceramic tiles to increase the degree of diving and the sense of speed. . When placing the subwoofer, you must pay attention to avoid resonance and affect the sound quality.
Five, home decoration to improve the sound effect
In ordinary families, the living room is generally used as a simple audio-visual room. The effect will have a bad influence. The sound effect will be improved to a certain extent by decorating or adding some simple items. First of all, since the living room is generally open and the house reverberates, it is necessary to make a certain indoor attraction through some decorations, such as Laying carpets on the ground, especially tiled floors, hanging some decorations on the walls, and using some large green plants for sound absorption in the corners of the house are all methods to prevent audio reflection. Some items that increase indoor sound absorption can absorb a large amount of sound in the room. It can reduce the reverberation time and reduce indoor noise to achieve the effect of reducing the reverberation and improving the sound effect.
Of course, if the audio-visual effects are considered at the beginning of the decoration and the sound absorption and diffusion of the walls are completed in advance, the effect of the theater will be achieved, but the engineering and cost are still unacceptable to ordinary families.
