Abstract: A method and apparatus for controlling acoustic gain during a non-speakerphone audio mode of computer system independent of acoustic gain during a speakerphone mode of the computer system is provided. The BIOS code of the computer system detects whether the computer system is in a speakerphone mode or a non-speakerphone audio mode. If the computer system is in a speakerphone mode, an upper gain limit is not applied to the microphone path of the computer system. If the computer system is in a non-speakerphone audio mode, a predetermined upper gain limit is applied to the microphone path of the computer system. The predetermined upper gain limit is preferably applied to the microphone path at either a microphone pre-amplifier or an audio mixer chip in the microphone path of the computer system.

Abstract: A stereo speaker system for portable computers which maximizes spatial impression by using rearward-firing speakers, mounted in the back of the display, in combination with forward-firing speakers mounted on the chassis or in the front side of the display.

Abstract: Piezoelectric speaker achieves radiation efficiency at low frequencies by using a piezoelectric speaker panel as a lumped parameter resonator. The speaker panel is mounted in a resonant system for generating translational motion. The resonant system includes suspension devices for suspending the panel to allow for translational motion of the panel and isolators for tuning the speaker panel to a predetermined frequency. At the predetermined frequency, the speaker panel achieves resonance in a low order mode, producing improved radiation efficiency at lower frequencies and translational motion of the panel not possible with a piezoelectric activator alone. The speaker panel may be included in a portable computer system, a desktop computer monitor, or other sound systems. In a portable computer system, a display screen or front speaker panel serves as a lumped parameter resonator, and the lid or rear speaker panel serves as a structure born vibration resonator.

Abstract: A portable computer system having a loudspeaker enclosure defined by a printed circuit board, a keyboard section cover and a gasket. A second enclosure is defined by an existing frame, the keyboard section cover and a second gasket. Advantageously, a loudspeaker mounting system provides positive urging of the speaker with the keyboard section cover and all other openings, such as the grill attachment apertures and any other openings, are sealed to achieve the total enclosure concept for a speaker system for a portable computer.

Abstract: A signal processing apparatus for processing data digital signals is disclosed. The signal processing apparatus includes a high-efficiency power switching amplifier that optimizes processing during low-power applications. A signal equalizer is further coupled to the power switching amplifier and has a plurality of signal bands for defining equalization characteristic desired for the signal processing system. A gain control unit is coupled to the signal equalizer for adjusting gain of the equalized input signal handled by the signal equalizer. Lastly, a digital amplitude compressor is coupled to the gain controller and the power switching amplifier and is programmable so as to compress only those signals having an amplitude greater than a first threshold level without compressing those signals that fall below that first threshold level. Typically, low-power applications cover wattage ranging from two to seven watts of power.

Abstract: A laptop computer is disclosed that includes an improved audio speaker system. The laptop computer typically is designed to have a first shell and a second shell that are attached together. Typically located within the first shell are a central processing unit, a keyboard, and other circuits such as a battery, a hard disk storage, and other connectors such as a PCMCIA slot. A video monitor is typically located in the second shell of the laptop computer and is coupled to the central processing unit via a system bust, or a video driver is provided that may be subsequently coupled to the CPU, such that the video driver drives the video monitor. Then, an audio speaker system is provided that in one embodiment is mounted in a back portion of the second shell that is located opposite the video monitor. This audio speaker system includes a transmission line comprising a first piezo speaker and a second piezo speaker.

Abstract: A portable computer docking station has a molded plastic housing within the interior of which are a ported speaker structure operative at low, mid and high frequencies, and a nonported speaker structure operative only at mid-to-high frequencies. The ported speaker structure has a ported enclosure section formed integrally with an exterior wall portion of the housing and having an open side. A first speaker is mounted on a lid member at an opening therein, with the lid member being secured to the ported enclosure section over the open side thereof with a seal member being sandwiched between the lid member and the enclosure section, and a sound absorbing structure being disposed within the enclosure section under the first speaker. The nonported speaker structure includes a second speaker supported on a second wall portion of the housing.

Abstract: A speaker system for use in a thin film video monitor apparatus is disclosed. The video monitor apparatus includes a thin film video display panel as well as a stiffening panel adjacent to the thin film video display panel. Next, a plurality of piezo speaker transducers are attached to one of the sides of the stiffening panel. The stiffening panel typically is composed of a material such as aluminum honeycomb sheets or a polycarbonate sheet. Other materials for use as the stiffener may include magnesium shells or ABS plastic. The speakers are defined so that a first sound channel and a second sound channel are provided, and these sound channels can define a left and right channel for proper stereo imaging. Between the video monitor and the stiffening panel is located an electromagnetic interference (EMI) shield.

Abstract: A portable computer system having a loudspeaker enclosure defined by a printed circuit board, a keyboard section cover and a gasket. A second enclosure is defined by an existing frame, the keyboard section cover and a second gasket. Advantageously, a loudspeaker mounting system provides positive urging of the speaker with the keyboard section cover and all other openings, such as the grill attachment apertures and any other openings, are sealed to achieve the total enclosure concept for a speaker system for a portable computer.