Abstract: An amplifier system comprises a first amplifier arranged to receive an input signal and a second amplifier arranged to receive a proportion of the input signal. A first potential divider is arranged to receive the output signal of the second amplifier and to feed a proportion of the output signal to the first amplifier. The first amplifier is arranged to subtract the proportion of the output signal of the second amplifier from the input signal to produce a difference signal for amplification by the first amplifier. There is also disclosed a method of amplifying a signal.

Abstract: A satellite speaker system includes a side firing low mid driver mounted in a sub-enclosure which is vented into a second sub-enclosure through an acoustic resistance vent and to a third sub-enclosure through a variable aperture second vent. The vents further serve as pivots to allow the side-firing speaker to be rotated through a predetermined range, simultaneously varying the aperture of the second vent. The pivots are isolated by o-rings to provide an airtight seal to the sub-enclosures, as well as to provide vibration control. Third, fourth and fifth resistively damped vents allow the first and second sub-enclosure to establish acoustic communication with the environment. The front firing driver/s that reproduces the mid and high frequencies are mounted in a fourth sub-enclosure.

Abstract: A switch circuit for controlling the supply of electrical power from an electrical power source to a load includes a power supply switch comprising input, output and control terminals. The circuit further includes an electronic switching device connected to the control terminal of the power supply switch and having an activating input; a momentary switch coupled to the activating input of the electronic switching device; and a charge storage element coupled to the momentary switch. In a first mode, closing the momentary switch in excess of a triggering time charges the charge storage element and triggers the electronic storage device to turn on the circuit to supply power to the load. In a second mode, closing the momentary switch connects the charge storage element to the electronic switching device to turn off the electronic switching device and the power supply switch, thus interrupting the supply of power to the load.

Abstract: A pouch with an integrated stand for releasably holding therein an electronic device. The pouch comprises a body having a longitudinally extending upper strap and a longitudinally extending lower strap. There is a side at each end of the pouch extending between the upper strap and the lower strap; and a rear wall extending between the sides. A cover is hingedly connected to the rear wall and is moveable between a first position closing the pouch, and a plurality of open positions. The plurality of open position comprise a first open position wherein the cover supports the body in the first orientation, and a second open position wherein the body in a second orientation. The sides may be of reduced depth compared to sides of the electronic device to create an opening through which access may be had to controls of the electronic device on the sides of the electronic device when the cover is in the first position.

Abstract: A portable device comprising a body, at least one wall of the body being of a translucent material and having an outer surface, an inner surface and an outer peripheral edge surface. The outer surface is coated with a first non-translucent material, there being a plurality of outer openings in the first non-translucent material to form a plurality of control indications. The inner surface is coated with a second non-translucent material, there being at least one inner opening in the second non-translucent material for at least one light source. The first non-translucent coating and the second non-translucent coating cause internal reflection within the at least one wall except for the outer openings and the outer peripheral edge through which light from the at least one light source is able to pass.

Abstract: A portable speaker system includes a telescoping enclosure containing at least two drivers. The telescoping enclosure includes an inner section nested within an outer section. Each of the inner section and the outer section includes at least one speaker driver. The telescoping enclosure is configurable in at least two positions, a retracted or collapsed position and an extended position. By extending the telescoping enclosure, greater channel separation and greater internal volume for the enclosure is achieved.

Abstract: A method of modifying low frequency components of a digital audio signal having left and right channel signals, including the steps of: a) filtering the left and right channels signals using respective left and right high-pass filters to form left and right high-pass filtered signals; b) filtering the left and right channel signals using respective left and right band-pass filters to form left and right low frequency signals; c) modifying the amplitude of the left and right low frequency signals to give modified left and right low frequency signals whereby signals with amplitude a where 0<a<a1 are amplified by a first constant value C1, signals with amplitude a1?a<a2 are amplified proportional to 1/a, signals with amplitude a=2a are unchanged, signals with amplitude a2<a<a3 are attenuated proportional to 1/a, and signals with amplitude a=a3 are attenuated by a second constant value C2; and d) combining the modified band-pass filtered left and right signals with the respective left and right hig

Abstract: A multimedia console incorporating an alphanumeric keyboard, and a musical key-bed is described for generating multimedia work product conveniently when coupled with a digital personal computer or optionally as a stand alone music equipment. The musical key-bed is optionally detachably coupled with a protective cover for providing ergonomic support when said musical key-bed is not being used.

Abstract: A method of improving 3D sound reproduction is described, in which virtual sound sources to be positioned behind a listener 10 are filtered using an HF-cut filter in order to remove distracting high-frequency components caused by incomplete transaural crosstalk cancellation. Sound sources placed in the rearward hemisphere of reference sphere 30 are filtered by an amount dependent on the position of the sound source in order to provide a smooth transition between the filtered and unfiltered hemispheres. HF-cut filtering is at a maximum when the sound source is placed directly behind the listener, and is progressively reduced as the forward hemisphere is approached. The invention offers an advantage in that virtual sound images may be placed more effectively behind the listener, given improved realism of 3D effects.

Abstract: A method and apparatus for improving the audibility of sound from a loudspeaker located close to an ear, comprises the steps of detecting ambient acoustic noise arriving from other sound sources using a transducer that provides corresponding ambient sound signals, inverting the polarity of said ambient sound signals and combining them with the signals being fed to the loudspeaker to reduce the audibility of said ambient acoustic noise, and passing said ambient sound signals through a filter having a predetermined average transfer function that compensates for the spectral modification of sounds travelling from the loudspeaker to the ear caused by the proximity of the ear of a listener in use.

Abstract: A method of processing a single channel audio signal to provide an audio source signal having left and right channels corresponding to a sound source at a given direction in space, includes performing a binaural synthesis introducing a time delay between the channels corresponding to the inter-aural time difference for a signal coming from said given direction, and controlling the left ear signal magnitude and the right ear signal magnitude to be at respective values. These values are determined by choosing a position for the sound source relative to the position of the head of a listener in use, calculating the distance from the chosen position of the sound source to respective ears of the listener, and determining the corresponding left ear signal magnitude and right ear signal magnitude using the inverse square law dependence of sound intensity with distance to provide cues for perception of the distance of said sound source in use.

Abstract: A portable speaker system for use with a laptop computer is configured for attachment to a screen of a laptop computer or alternatively for a free standing configuration. The speaker system includes an acoustic chamber for containment of the sound reproducing mechanism, a second chamber, and a damped hinge mechanism for movable connecting the acoustic chamber and the second chamber.

Abstract: A base for supporting a camera or other electronic device includes a body member connected by a hinge mechanism to a support member and configured to rotate about a camera tilt axis. The support member is attachable to the base of a video camera. Two front legs are fixed in position relative to the body member. A rear leg is attached by a pivot connection to the body member. The base is configured such that the rear leg may be moved by pivoting the rear leg about the rear leg pivot axis to engage a back surface of a laptop screen or flat monitor or onto a flat horizontal surface. The camera tilt axis and the rear leg pivot axis are substantially parallel.

Abstract: A base for supporting a camera or other electronic device includes a body member connected by a hinge mechanism to a support member and configured to rotate about a camera tilt axis. The support member is attachable to the base of a video camera. Two front legs are fixed in position relative to the body member. A rear leg is attached by a pivot connection to the body member. The base is configured such that the rear leg may be moved by pivoting the rear leg about the rear leg pivot axis to engage a back surface of a laptop screen or flat monitor or onto a flat horizontal surface. The camera tilt axis and the rear leg pivot axis are substantially parallel.

Abstract: Auto-detection of audio formats is provided by using an auto-detect element to exploit differences among multiple formats to output a format select signal corresponding to the input to the auto-detect element. In a preferred embodiment, edge detection circuitry and a time counter are employed to recognize multiple audio formats automatically. The format select signal output from the auto-detect element is output to a multiplexer, or other switching means for switching among multiple input formats, so that the correct input signal processing is used. The auto-detect element removes the need for an external hardware select pin, thereby reducing the number of input pins to the circuit.

Abstract: An audio system and circuit are disclosed that are operable in either a first configuration and a second configuration. The first configuration includes sound processing circuitry, a primary connector, and a header. The second configuration adds an optional secondary connector to the header. The system and circuit mutes or turns off the audio signal at the primary connector and the main output contacts (if any) upon insertion of a plug into the secondary connector in the second configuration. The system and circuit also optionally mutes or turns off the audio signal at a main output contact upon insertion of a plug into the primary connector in each of the first and second configurations. The system may also employ logic switches or FETs to interrupt the audio signal upon insertion of a plug into the secondary connector. The system uses a simple switchless interconnection between the secondary circuit and the main system.

Abstract: A device for detecting a crack in an optical disc including a transmitter to propagate an optical signal through the optical disc and a receiver to detect the propagated signal. From the pattern generated from the received signal, a microcontroller makes an analysis to determine if a crack is present on the optical disc. The method may be incorporated into a conventional disc drive as a new crack detection mechanism.

Abstract: Original head-related transfer functions (HRTFs) are modified for a non-standard dimensioned head. The HRTF includes a near-ear response function, a far-ear response function, and an inter-aural time delay (ITD). The modified HRTF resembles an HRTF approximating that derived for a listener having different head and/or ear dimensions to the standard dimensions. The ITD value of the HRTF is multiplied by a given scaling factor independent of frequency. The near ear and/or far ear response function of the HRTF is multiplied by a constant scaling factor in the frequency domain independent of time delay, to expand or compress the functions in the frequency domain. The near ear and/or far ear response function of the HRTF are provided with a positive or negative offset value in the frequency domain. The amplitude of the near ear and/or far ear response function of the original HRTF(s) is (are) multiplied by a given gain factor.