The rubber boot is a critical component of the speaker's suspension system, which is responsible for keeping the cone moving in a controlled manner. It helps to absorb the energy from the cone's movement and prevent it from bottoming out, which can damage the speaker and distort the sound.
In addition to its role in preventing distortion, the rubber boot also helps to improve the speaker's efficiency. This means that it can produce more sound from the same amount of power. This is because the rubber boot allows the cone to move more freely and efficiently, which increases the amount of air that it can displace.
As a result of its ability to prevent distortion and improve efficiency, the Scan-Speak rubber boot is a popular choice for high-performance speaker designs. It is particularly well-suited for woofers and subwoofers, which need to be able to handle the large amounts of power and excursion that are required to produce low frequencies.