8 Ohm 30W Subwoofer Speaker – 4 Inch Bass Driver for DIY Audio

The SWS-30W-8 is a 4-inch subwoofer speaker designed to reproduce low-frequency audio with an 8-ohm impedance load. An 8-ohm driver presents a lighter load to an amplifier than a 4-ohm equivalent, which makes it a practical choice for amplifiers that are not rated for low-impedance operation, for multi-speaker series configurations, and for projects where reduced current draw and lower heat generation are priorities. This 30W speaker is intended for bass reinforcement in compact audio systems, DIY speaker builds, car audio upgrades, and portable sound projects.

The driver features a 25.5mm voice coil, a cone diameter of 10cm (4 inches), a screw-to-screw mounting distance of 11.5cm, and an overall height of 6.5cm. The moving assembly is suspended to support bass reproduction, and the magnet structure is sized to deliver useful low-frequency output within the 30W continuous power rating. As with any passive subwoofer, an appropriate amplifier is required—the speaker does not include an onboard amp, crossover, or enclosure. The 8-ohm impedance also makes it possible to wire two units in parallel for a 4-ohm total load or in series for a 16-ohm load, giving builders flexibility in matching the driver to their amplifier and box design.

This 8 ohm bass driver speaker is suitable for use in home audio systems, computer speaker setups, portable Bluetooth speaker projects, stage monitors, and automotive sound systems where space is limited but bass output is still desired. Its compact 4-inch frame fits small enclosures and replacement applications, and the 30W rating provides a comfortable margin for typical listening levels when paired with a suitably rated amplifier.