For longer life, the woofer has a rubber surround and poly-cotton spider. The poly-cotton spider is about 10 times as wear resistant as a standard cotton spider.
All subwoofer designs, especially low cost subwoofers, involve tradeoffs in design. You cannot have a small subwoofer that goes very low, plays very loud and costs very little. Traditionally, the engineer decides what tradeoff he or she thinks is best for the consumer. The consumer has to take it or leave it.
The VTF series changes all that. It allows you, the user, to choose the tradeoff. If you enjoy music that is loud but does not have much deep bass, set the VTF series for max output. That way, you get maximum dynamic range with the lowest distortion. If you like music with deep bass, set it for maximum bass extension to reproduce the deep bass accurately. You can even switch between the two modes depending on what you play. That means effectively you get a subwoofer that can play loudly, and can play low, all in one, at one low price! HSU in America HSU in Canada