Recently, I saw that many friends were vague about the concepts of subwoofer and lfe, so I wanted to write an article on bass first. After all, bass has a great impact on the effect of home theater.
An American home theater designer once said that bass is like salt. Less salt makes the food tasteless; But too much of it masks the freshness of the food. The same is true of bass. If there is a lack of low frequency, the appeal and impact of audio-visual programs will be greatly reduced; If there are too many low frequencies, it will affect the definition of audio-visual programs. Therefore, appropriate is the most ideal.
The speaker configuration you can see in the AV Amplifier / decoder today, such as channel large, small and other settings, is bass management.
Bass management originated from the combination of satellite speaker + subwoofer launched by M & K and triad in the 1980s. At the same time, Dolby lab has also launched a low-frequency distribution system, which allows the AV power amplifier / decoder to distribute the low-frequency signal of the central channel to other channels for playback.
In 1990, Lucas pictures introduced the thx certification standard, which requires that each channel in the home theater can reach the maximum sound pressure level (low frequency) of 105dB at the audience position, so as to meet the standard of film studio. However, after the introduction of the standard, it was found that it is unrealistic to achieve the highest sound pressure level of 105dB for each channel in the low frequency band in the family. Unless the customer uses a very large speaker (dual 12 inch or 15 inch subwoofer). Therefore, thx developed a simple low-frequency management system, allowing a single subwoofer to be responsible for the low-frequency restoration of all main channels (L / C / s). In this way, while experiencing the surging bass in the family, the volume of the main box is greatly reduced.
In 1995, Dolby laboratory and DTS launched an independent 5.1 channel system respectively, adding an independent channel - lfe (low frequency effects), which is translated into low frequency effect channel in Chinese. When playing the signal of this channel, the maximum sound pressure level at the audience position can reach 115dB. If you don't experience the legendary feeling of "low-frequency beating your heart", it can only show that your system is less than 115dB. The living room party is almost impossible. If you can get there, it is estimated that not only the whole building, but also the neighbors of the whole community will come to you for trouble. How does 115dB feel? Have you been to the disco? Just like that.