Created on 15.01.2008 14:22.
Updated 01.24.2021 16:17.
In order to choose the right speaker system for a home theater that best suits the conditions in which it will have to work, it is necessary to decide on the following parameters:
This is the power input range for passive speakers, and the power of the built-in amplifier for active speakers.
The unit of measure for power is Watt.
Lack of amplifier power affects both the volume and the dynamics of the playback. However, the output power of the amplifier should not be higher than the power of the acoustics, as this can lead to mechanical damage to the speakers. Based on the size of the room, a 60–80 W speaker system is sufficient for a room not exceeding 17 m². If the dimensions are 20–30 m², then the power should also be higher – about 100 watts. A large room (more than 30 m²) requires 150 W acoustics.
The higher the sensitivity of the system, the louder the sound it can produce at a given power. Using acoustics with high sensitivity, you can have a not too powerful amplifier, and vice versa. A value of 85 dB / W / m, for example, means that this system is capable of creating a sound pressure of 85 dB at a distance of 1 meter from a 1 Watt speaker. The sensitivity of conventional acoustics ranges from 84 to 102 dB.
Conventionally, the sensitivity of 84–88 dB can be called low, 89–92 dB – medium, 94–102 dB – high.
In order to increase the volume by 2 times, it is enough to increase the sensitivity by only 1 dB, while the power for this will have to be increased several times. In general, the higher the sensitivity, the better, but remember that a powerful amplifier can easily damage sensitive speakers.
Frequency Response Range
This is the frequency range within which this system has a flat frequency response, in other words, it can reliably reproduce an audio signal. It is known that the human hearing organs perceive sound with a frequency of 20 to 20,000 Hz.
However, the audio signal has a complex shape, that is, it contains components with different frequencies, including those outside the audible range.
Therefore, the developers of both amplifiers and loudspeakers try to achieve a frequency range that goes beyond 20,000 Hz for the most accurate reproduction.
If it is planned to use a subwoofer in the system (the range of reproducible frequencies is 2-250 Hz), then the frequency range of the rest of the acoustics may not cover the low-frequency interval. Otherwise, the speaker system must reproduce the entire sound range (20-40,000 Hz).
Type of shell
When choosing a speaker system, you should pay attention to the type of enclosure, which are: closed type, with a bass reflex, with a sound labyrinth.
The simplest is a closed-type case, which also improves the transient response of the speaker system. However, the presence of an enclosed space increases the frequency of the lower resonance, which negatively affects the transmission of low frequencies. Most modern speaker systems use a bass reflex enclosure type.
The next thing to pay attention to is the type of acoustics (floor, shelf). In terms of dimensions, these two types hardly differ, since the shelf acoustics, despite the name, are best fixed on special stands, which makes the advantage of compactness somewhat meaningless.
When choosing a floor-standing speaker, you can count on deeper and more powerful bass thanks to the large volume of the cabinet.
But for the same reason, that is, because of the size, it is much more difficult to ensure the rigidity of the case of a floor-standing speaker than a shelf speaker. To increase the rigidity, internal partitions, screeds, stiffeners are used, it is necessary to use chipboard of a large thickness, and this increases weight and cost.
The presence of an amplifier – an active or passive speaker system.
In order to make a choice in favor of this or that solution, it is not out of place to know that in active acoustics, each frequency band (that is, in fact, each speaker) is amplified by a separate amplifier, and crossover filters are active and are located at the input of the amplifiers, and not at the output.
Hence the following advantages of active home theater speakers:
- An active filter is easier to adjust than a passive one. Therefore, in the conditions of serial production, it provides the best filtration quality.
- The speakers are connected directly to the amplifiers for better sound quality.
- Active systems usually have a wider frequency range.
- Active speakers have a volume control, which increases ease of use.
The main disadvantage of active acoustic systems is the need to supply a linear signal and voltage to each speaker. Passive acoustics do not have this drawback, but, among other things, they require an external amplifier.