Home theater basics: AV power amplifier selection

A home theater system allows users to enjoy movies, listen to hifi music and karaoke entertainment at home. A home theater needs three parts: a signal source (blu-ray player, DVD player, hd player, HTPC, CD player, etc.), a power amplifier, and a terminal output device (projection, HDTV, hi-fi speaker, etc.).

Home theater basics: AV power amplifier selection

AV power amplifier is the core of audio playback, its role is multi - channel sound playback function. When it comes to multi-channel playback, the standard of surround sound is indispensable. When choosing an amplifier, it is important to pay attention to whether the amplifier has the current surround sound standard certification:

1. Dolby prologic surround sound.
2. Dolby Digital surround sound.
3. DTS surround sound.
4. THX Surround EX (7.1 channels).
5. Dts-es Discrete surround sound (6.1 channel), etc.


At the very least, a home AV amplifier should have the decoding and playback function of dolby digital surround sound, because dolby digital is the mandatory audio standard for PAL DVD set by DVD alliance in December 1997. Whether the AV amplifier has this function is the basic point of choice for users. Other certifications are a direct reflection of the amplifier level.

In addition to the obvious authentication, there are many indicators and parameters to evaluate the quality of an AV amplifier.

1. Output power: refers to the energy obtained on the speaker connected to the power amplifier. For the power amplifier, its rated power (the effective power that the power amplifier can continuously output under the condition of authenticity) is an effective index to evaluate the performance of the power amplifier.

2. Distortion: the output of the equipment cannot completely reproduce its input. The distortion of waveform or the increase or decrease of signal components are called distortion.

3. Dynamic range: the level difference between the strongest part of the signal and the weakest part of the signal.

4. Damping coefficient: the damping coefficient refers to the ratio of the load impedance to the output impedance of the amplifier, and is a performance index to measure the damping effect of the amplifier's internal resistance on the speaker.

5. Output impedance: the output impedance of the amplifier refers to the equivalent internal resistance of its output terminal to the speaker, which should be consistent with the rated input impedance of the speaker.

6. SNR: SNR refers to the decibel difference between the audio signal level and the noise level. The higher the signal-to-noise ratio, the lower the relative noise of the amplifier and the better the sound quality.

7. Degree of separation: degree of separation refers to the ability of the surround sound decoder in AV amplifier to restore the audio coding signal to various sound channel signals. In the amplifier with poor separation degree, the acoustic image positioning is inaccurate, the acoustic field is not full, the acoustic image consistency is poor and so on.

Perhaps these indicators are confusing, but the most intuitive ones are simply the driving capacity (that is, the amount of power) and the weight of the amplifier.
 
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