Power
Rated power of the subwoofer. Technically, this is the highest average (rms) sound power at which the device can work normally (without sound distortion and damage to components) for an unlimited time. Simply put, the more powerful the subwoofer, the louder it is. The choice for this parameter depends primarily on the size of the space / room that is planned to be covered; detailed recommendations for different situations can be found in special sources.
Also, the power is directly related to the characteristics of the amplifier used with the subwoofer. For active subwoofers (see "Type"), this item actually indicates the nominal power of the built-in amplifier; the speaker itself can be more powerful, but it doesn't matter anymore. For passive models, the power rating corresponds to the highest amplifier power that can be connected to the speaker without the risk of damaging it at high volume.
Impedance
Subwoofer AC impedance. This parameter matters primarily when connected to an external amplifier: if the impedance is lower than that of the amplifier, sound distortion is possible, if the impedance is higher, the subwoofer may sound quieter than we would like.
Frequency range
The range of audio frequencies reproduced by the subwoofer. As a general rule, the wider the frequency range, the richer the sound and the more detail the speaker can convey. However, it is worth remembering that subwoofers as a class are designed for low and ultra-low frequencies in the range from 20 to 150 (sometimes 200) Hz. Therefore, in fact, a significant difference in sound is noticeable only with a large difference in the reproducible ranges (for example, 20-200 Hz and 50-150 Hz).
Also, do not forget that an extensive frequency range is not yet a guarantee of high-quality sound; and in some cases (for example, if the main speakers of the speaker also cope well with low frequencies), it may be completely redundant.
Speaker size
The diameter of the speaker(s) installed in the subwoofer.
It is believed that the larger the speaker (
15 inches or more), the more power it can produce and the deeper the bass sound on such acoustics. However, in modern subwoofers, manufacturers use various tricks to achieve good sound depth even with relatively small speaker sizes (
10 inches). Therefore, it is possible to unambiguously compare different models only if they differ significantly in this indicator; and even then in such cases it is worth paying attention not so much to the diameter of the speaker, but to the price category. The golden mean among sizes are
12-inch subwoofers.
