Size
The size (diameter) of the main subwoofer speaker. In all types of subwoofers, this parameter primarily affects the power and depth of sound: the larger the speaker, the louder it is and the deeper the bass it can provide (ceteris paribus). However with an increase in the size and dimensions, they increase accordingly, which determines the installation possibilities. The latter is especially true in Free Air subwoofers (see "Execution"): some cars are initially equipped with "seats" for a certain size, and it is difficult to install models with other dimensions there.
Now on the market there are subwoofers with such popular sizes:
5" (13 cm),
6" (15.25 cm),
6.3" (16 cm),
6.5" (16.5 cm),
6.75" (17 cm),
8" (20 cm ),
8.25"(21cm) , 9" (23cm
), 10" (25cm
),
11" (27cm),
12"(30cm) ,
13" (33cm),
15"(38cm) ,
16 " (40 cm),
18" (46 cm).
Sensitivity
Sensitivity determines the loudness of the subwoofer when a signal of a certain power is connected to it: with equal signal power and impedance (see below), the subwoofer with the higher sensitivity will sound louder.
Impedance
The electrical resistance of a subwoofer when a signal is applied to it. This parameter is important primarily for selecting a subwoofer-amplifier pair: at a lower impedance than that of the amplifier, the subwoofer will distort the sound, at a higher impedance the sound will be too quiet.
For dual voice coil models (see above), the impedance is specified for one of the voice coils.
Resonant frequency
The natural frequency of the cone in the subwoofer speaker, namely the frequency with which the cone will oscillate if the speaker is suspended freely in the air and a single impulse is transmitted to the cone (for example, by clicking on it with your finger). In subwoofers, this parameter determines, in particular, the lower limit of the frequency range (see above): at frequencies below the resonant sound power drops sharply. Accordingly, for deep rich bass, the resonant frequency should be as low as possible. This parameter is also used to calculate the size of the enclosure for the subwoofer.
Woofer Diameter
Subwoofer main speaker size. The diameter of the woofer determines the size of the device (see above).