Abstract: A quick release hold-down mechanism for releasably securing protective covers and expansion cards within a personal computer comprises a press plate for exerting a force upon the flange of a protective cover or the flange of an expansion card. A tension arm is operatively coupled to the press plate for holding the press plate in place. The tension arm is releasable to and securable within a fixed position such that the press plate maintains the force upon a surface of the expansion card or protective cover to maintain the expansion card or protective cover in its desired location. The tension arm is rotatably moved which causes the press plate to pivot through an arc, around a pivot means. By this rotatable motion of the tension arm, the press plate engages the surface of the installed protective cover or expansion card. More than one protective cover and expansion card can be installed and any number of either or both can be thus secured.

Abstract: A setup to be used in a home theater or sound reproduction system for handling low frequency sound signals with a signal source providing several full bandwidth digital sound channels and at least one digital low frequency subwoofer channel includes a delay-and level control unit at least for each full bandwidth signal channel, which is equipped for a speaker not capable of reproducing low frequency sounds. A first summing stage creates the sum channel by summing the delay-and level controlled signal channels. A second summing stage adds a low frequency subwoofer channel to the sum channel in order to create a digital bass channel. A DA-conversion, amplifying, lowpass-filtering and volume control unit processes the digital bass channel in order to create an analog bass channel.