Do you know about the role of home theater power amplifier?

                               Do you know about the role of home theater power amplifier?

Creating a great home theater system starts with careful consideration of the various acoustic and optical components in an audiovisual room to create a great audiovisual space. With the introduction of audio-visual space design, we had a comprehensive discussion on the proportion and size of the room and the optimal reverberation time for multiple time periods. For the equally important audiovisual equipment, the following will unravel the mysteries of audiovisual equipment for everyone.

In home theater systems, ordinary audio-visual enthusiasts tend to focus on home theater speakers, home theater projectors and home theater projection screens, while ignoring the home theater amplifiers hidden behind them. Home theater amplifiers can actually be called A/V amplifiers or AV amplifiers, because it is different from traditional two-channel HiFi amplifiers. Line upscaling and digital processing can be said to be the control center of the entire home theater system. If you want to step into the wonderful world of home theater, you first need to know the home theater amplifier, which is also a key step in creating a home theater system.

The reason why the home theater amplifier is called an amplifier is that it has the function of audio amplification and is also the audio and video processing center of the home theater. On the one hand, it receives the video signal and multi-channel audio signal from the signal source and decodes, processes and transmits it. , on the other hand, transmits the processed audio and video signals to the home theater projector and home theater speakers. Home theater amplifiers can be divided into three types: pre-amplifiers, post-stage power amplifiers and combined amplifiers according to their working methods. The pre-amplifier can also be called the pre-processor, which is mainly responsible for the decoding and processing of audio and video signals, and also has a certain amplification effect. The post-stage power amplifier is mainly to achieve signal amplification and speaker drive. The combined amplifier combines the characteristics of a pre-amplifier and a power amplifier. Incorporated amplifiers are an easy and quick implementation for normal home use. For enthusiasts who pursue better sound and picture performance, the combination of front and rear is a better choice. Usually a pre-amp can be used with one or more mono, dual or multi-channel post amplifiers.

In the audio part, signal amplification and processing are two important links. First, we discuss the various types of AV amplifiers in terms of audio amplification. Ordinary stereo HiFi amplifiers can be divided into two types: tube amplifiers and transistor amplifiers according to different core amplification components. However, since the main purpose of the home theater amplifier is to play blockbuster movies, it is necessary to maintain a high-power sound pressure output for a long period of time. From the aspects of working stability, efficiency and safety of the amplifier, the volume is small. , transistor amplifiers with low calorific value and larger current output are more suitable for home theater amplifiers, so home theater amplifiers at this stage are all transistor amplifiers.

Transistor amplifiers can be divided into A, B, AB, D, G and H and other working modes according to the different working modes of the output stage. Among them, class AB and class D amplifiers are commonly used in home theater amplifiers. These types of amplification methods have their own characteristics, and each subsequent amplification method can be improved according to the shortcomings of the original type. For example, Class A has high-quality linear performance with low distortion but high power consumption. Class B improves the problem of power consumption, but leads to the problem of large distortion. AB, G, and H are the balance between low distortion and low power consumption. Class D is to improve the deficiencies of traditional analog amplification through the concept of digital amplification processing.

Audio signal processing is an important part that cannot be ignored in home theater amplifiers, mainly focusing on the pre-amplifier and the front-end part of the combined amplifier. The working method is to receive the audio signal from the signal source, analyze the signal type, process and decode it, convert it into an analog audio signal, and then hand it over to the amplifying part for processing.

The core part of audio signal processing lies in the decoding of various audio signal formats, such as decoding for high-definition audio formats, including Dolby TrueHD, DTS-HD Master Audio, LPCM, etc., in addition to various DSP sound effects processing, room automatic sound field Correction systems are all important components.

For decoding support for high-definition audio formats, after several years of development, almost all AV amplifiers can do it. In terms of DSP sound effect processing, there are currently two different implementation methods. One is that YAMAHA (YAMAHA) integrates it into the home theater amplifier by studying the sound environment of different scenes in various places, such as concert halls, theaters, etc. , when in use, simulate the sound effects of concert halls and theaters according to different program source scenes. The other is the processing of real-time sound expansion, such as Dolby Pro Logic IIz, Audyssey DSX and DTS Neo:X, etc., which analyzes the structure of the audio signal in real time, and expands the sound field through precise and accurate algorithms. Among them, Audyssey DSX and DTS Neo:X are two relatively new technologies that can expand conventional 7.1-channel signals into 11.1-channel output.

Maybe the friends who have just come into contact with the home theater system still don’t know how to get good sound effects. In short, it is necessary to adjust the relevant options in the amplifier according to the room environment and the placement of the speakers. At the same time, it is necessary to combine the sound pressure meter and tape measure. It is a rather tedious process. But now mainstream home theater amplifiers have added the automatic room sound field correction function. Just plug in the microphone that comes with the amplifier, and you can automatically set options such as the sound level, the distance between the speaker and the listening position, and the room EQ. , including MultEQ, MCACC and YPAO, etc. Taking MultEQ as an example, it can automatically correct various aspects such as the distance of the listening position, sound pressure, and room EQ, so as to minimize the impact of room sound field defects on the sound quality.

Network audio playback and intelligent wireless control are very hot functions recently, and major manufacturers such as Onkyo (Onkyo), Pioneer (Pioneer), Denon (Tianlong), Yamaha (Yamaha), etc. have all added these functions. Users can connect to the Internet through the home theater amplifier, listen to numerous Internet radio stations, and play shared high-definition lossless audio files in the local area network. Some models can also realize real-time upgrade of firmware through the network to improve various functions in the fuselage. Intelligent wireless network control is to use Android and iOS intelligent mobile platforms, such as mobile phones, tablet computers, etc., to control the home theater amplifier, providing users with another control method other than the remote control.

In addition to this, the processing of the signal also includes multi-room music playback. Most of the high-quality home theater amplifiers will be equipped with Zone2 (second zone) or Zone3 (third zone) functions. By setting up a complete music system in different rooms, a multi-room music playback system is completed. In addition, many models will also have IR, RS-232 or other intelligent control terminals. Through these terminals, they can be connected to the intelligent central control system at home, and the home theater amplifier can be integrated into the intelligent home control system.