Component of a speaker driver that holds the voice coil and rear of the diaphragm in position near the magnet and also acts as a spring or bungee to return a moving diaphragm to its stationary position. The spider is essentially the equivalent to the speaker surround or suspension, but instead of taking a position at the front of the diaphragm, as the surround does, the spider works at the rear of the diaphragm. he spider is necessary to hold the voice coil in close proximity to the magnet without letting them touch. This essential function allows the voice coil and magnet to interact creating motion. The voice coil generates a magnetic field when current passes through it creating attractive and repulsive forces in relation to the stationary magnet. The spider connects to the diaphragm or to the voice coil and to the basket (the part of the speaker driver holding all the pieces together). The spider is flexible so that it allows the voice coil to move in relation to the magnet. hile the spider is flexible, however, it is also somewhat rigid in that it pulls back to its original, stationary position when the voice coil is not moving (when no signal is being applied to it). This helps to bring the speaker driver back to a zero point or resting position from which it can move forward and backward. he spider is round in shape, and most spiders have rings of hills and valleys moving outward from the diaphragm (corrugated design). The spider plays a vital role in the overall structure of the speaker driver holding the rear of the driver in place and bringing it to a rest when not being fed a signal.