Home theater systems usually operate with up to ten speakers.
Unlike a Hi-Fi system, a home theater is an extremely complex system.
The system consists of an amplifier, a CD or network player, and two identical speakers for stereo playback. A home theater system, on the other hand, consists of a subwoofer and up to nine additional speakers, whose transmission range should be precisely tuned to the frequencies of the subwoofer. The fine-tuning of woofers and tweeters/midrange drivers is also a challenge even with three-way speakers: the developer must ensure that the volume and phase of the woofers perfectly match those of the media and woofers. Only in this way can an absolutely linear frequency response be guaranteed. In home theater systems, it is much more difficult to set up the woofer—in most cases, a separate subwoofer. This should not only be set up for two tweeters and midrange speakers, but also for the left and right main speakers, the center speaker, and the two surround effects. It is therefore not enough to set up the correct number of identical speakers, as with a stereo system. This old-fashioned Hi-Fi approach does not apply to home theaters.
In a home theater, the individual speakers must perform completely different tasks, which are controlled by the electronics of the AV receiver. It is therefore important that home theater systems combine the electronic settings of the amplifier with the characteristics of the speaker. This is an example of the problem: An unlicensed speaker manufacturer divides the frequency range of its satellite subwoofer system at 100 Hz with an 18 dB crossover slope. This creates the basis for a harmonious interplay of the speakers. However, if this speaker set is now connected to an amplifier whose subwoofer output is designed for a crossover frequency of 90 Hz with a steep slope angle of 24 dB, the connection values do not match. Since there is no standardization, every manufacturer of AV receivers and speakers can do whatever they want. Deviations of 80 to 90 Hz are still justifiable, but the usual differences of 200 to 80 Hz also mean serious low-frequency errors.
Mixing of film soundtracks for movie theaters
However, there are still other fundamental differences between a Hi-Fi system and a home theater system. For example, the Hi-Fi sound of a CD is mixed from the beginning so that the music sounds best where it is usually heard: in the living room. In contrast, film media such as laser discs, DVDs, or Blu-ray discs contain the original soundtracks of the films, as they were mixed for playback in large movie theaters.
While the audience is far away from the front speakers of the theater, the distance to the screen area is relatively short. In order for film soundtracks to sound as good as possible in the home theater, the sound mixed for the cinema must be electronically processed in a decoder. However, since the home theater has smaller sources of interference and less audience noise and soft seats, the front speakers are not covered by the screen, and the high frequencies must be radiated much louder due to the large distances in the theater.
