Skip to content

Audiophiles

What is a Passive Radiator? 2022

What is a Passive Radiator?

From the front, a passive radiator resembles a typical driver (speaker), but from the back, it appears to have been completely gutted. Look at the photo on the right. A passive radiator is a speaker that only has the cone, suspension, and frame; there is no magnet or electronic structure attached to it. However, a typical speaker can serve as a passive radiator; the “guts” are only unnecessary.

A passive radiator, as its name implies, is essentially a reactionary device. The physical forward/backward movement of the speaker has an impact on the internal air pressure of the enclosure when a driver (such as a subwoofer) is mounted to a sealed speaker box (enclosure). When a passive radiator is placed to the same speaker box as a driven speaker, the passive radiator starts to move forward and backward as if it were also a driven speaker due to changes in internal air pressure brought on by the driving speaker’s motion. Similar to a typical driver, the passive radiator generates sound frequencies when it moves.

How do Passive Radiators Work?

A straightforward tool called a passive radiator speaker boosts a speaker system’s low frequency response (bass). In a nutshell, the concept is that when used appropriately, a passive radiator can give a speaker system performance qualities that are comparable to those of a much bigger system.

To create audible bass frequencies, a lot of air must be moved. Larger woofers have traditionally produced bass that is louder and crisper. This tradition has been broken by passive radiator technology.

What are the Advantages of Passive Radiators?

Small sound systems are best suited for passive radiator designs. As the maker tunes with the interior pressure of the speaker cabinet, a passive radiator system resonates the low frequency. The speaker is more effective because it is passive.

When the volume is increased, the active driver travels with a higher amplitude. The likelihood of sound distortion is increasing as a result. A portion of the active driver’s movement is isolated by the passive radiator driver if one is fitted along with the speaker cabinet. It improves the bass response and enables the user to hear more volume without distortion.

To produce a low frequency at a larger sound pressure level, a speaker driver that is sizable and able to move in higher amplitude is needed. Practically speaking, a huge speaker driver cannot be used in a small sound apparatus.