Comparison JBL S2-1224SS vs Supra SRD-T30A

— Case Box. Literally "box". The simplest type of case, in fact, is a box of medium dimensions, designed for installation in the boot.

— Compact. This option means rather than the shape, but the size of the case — as the name implies, it includes devices that have small dimensions. Such subwoofers are as simple as possible to install, some models can be installed directly under the seat. At the same time, their sound quality and power are usually lower than those of full-size ones.

— Tube. The case is in the form of a pipe, on one of the ends of which a speaker is displayed. This form does not significantly affect the sound characteristics, it plays mainly an aesthetic role — subwoofers-pipes look quite stylish.

— Active. Subwoofer equipped with its own built-in amplifier. Such a subwoofer can be connected directly to the signal source, without any additional amplifiers; while the built-in amplifier, by definition, has characteristics that best match the parameters of the speaker. And when using other amplifiers, an active subwoofer reduces the load on them, which has a positive effect on sound quality and power. In addition, your own amplifier can be equipped with its own sound tuning tools and other additional features. On the other hand, all this affects the cost of the device, and active models are somewhat more difficult to install, because. require separate power supply.

— Passive. Subwoofers not equipped with their own amplifier. They are cheaper than active ones and easier to install. work without a separate power supply, however, the connection is fraught with some difficulties: for normal operation, an amplifier is needed, the characteristics of which (in particular power and impedance, see below) must optimally match the parameters of the subwoofer.

The average (root mean square — RMS) power of the input signal, at which the subwoofer is able to work continuously without negative consequences (damage, failure) for at least an hour. The rated power of the subwoofer must be greater than the power of the amplifier connected to it — in order to avoid overloads.

The maximum signal power that the subwoofer is able to withstand for a short time (up to several seconds) without any negative consequences. When selecting an amplifier-subwoofer pair, it is recommended to take a subwoofer with a maximum power of at least twice the maximum power of the amplifier. In general, the higher the maximum power, the more resistant the subwoofer is to overloads.

The range of audio frequencies reproduced by the subwoofer. It is believed that the human ear is capable of perceiving a frequency range of the order of 16 – 20,000 Hz, but in this case note that the subwoofer is designed to reproduce the lower frequency band (up to 200 Hz). Accordingly, in the case of the lower limit of the range, everything is simple: “the lower, the better”; the upper one should not be lower than the lower limit of the main car audio — otherwise there will be "gaps" in the frequencies, which will affect the sound quality.

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.

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.

Since the subwoofer was originally designed to reproduce bass, in fact, in this case, it implies the presence of its own volume control, which allows you to change it without affecting the signal source. This allows you to easily set the desired bass level relative to the rest of the sound of the audio system (for different cases, this ratio may be different).

The presence of a high-voltage input at the active (see "Type") subwoofer. Such an input greatly expands the possibilities for connection. Usually active subwoofers are connected via a linear (low-voltage) input directly to the radio. The high-voltage input allows you to connect the speaker to a separate power amplifier, like a passive subwoofer.