Sony Corporation

Sony United Kingdom Limited

Paul Anthony Frindle

John William East

Simon Irving Harrison

Peter Charles Eastty

William Edmund Kentish

John W Richards

Tetsuya Konishi

David Charles William Richards

A digital audio processor comprises at least one digital audio sample mapping module and produces a sequence of output digital audio sample values by applying a quasi time-invariant transfer function to each input digital audio sample value, the transfer function being arranged so that a ratio of root mean square signal level to peak signal magnitude is lower for the input digital audio signal than for a corresponding portion of the output digital audio signal.

Digital audio signal processing

A method of generating filter coefficients to provide a desired nth order filter response comprises adding one or more substantially co-located pole and zero pairs to form an (n&plus;m)th order filter having the desired nth order filter response.

Digital filter

A capacitive touch detection system, which can be used to inhibit motorized faders in an audio mixing system, includes touch detection circuits each having a respective conductive area for touch determination by detection of increased capacitance at the conductive area. The touch detection circuits are operable during predetermined active periods initiated by a clock generator which activates a pulse generator to produce an enable pulse EP1 for one detection circuit. The trailing edge of that enable pulse EP1 generates a non-overlapping enable pulse EP2 for the next detection circuit, and the process continues so that no more than one detection circuit is active at any time. This minimizes interaction between detection circuits if more than one conductive area is touched simultaneously.

Capacitive touch detection

An audio mixing console provides for a selected group of channels to be assigned to a bank of channel controls for a channel function (e.g., a solo mode) with a global function indicator for indicating that the predetermined channel function has been selected for at least one channel. A global function cancel button for canceling the channel function in all channels is provided. Various solo modes can be selected. A logic button includes a button member moveable between a raised position and a depressed position, a switch contact open in the raised position and closed in the depressed position and a logical latch (e.g., software-implemented) responsive to a first closing of the switch on a first depression of the button to change from an inactive state to an active state and to a second opening of the switch on a second release of the button to change from the active state to the inactive state. An automation mode controller is operable, in a first pass, to store on-going switch timing at which the user operable control is switched from off to on and off-going switch timings at which the switch is switched from on to off for automatically reproducing the control switchings in a subsequent pass.

Audio mixing console

An audio mixing console includes user controls which can be dynamically allocated to respective processing channels enabling a compact audio mixing console to be provided with full functionality, but with only a relatively small number of user operable controls including allocatable channel faders and allocatable audio signal processing control knobs and buttons, etc. Individual control values for the user operable control can be updated, maintained and retained for each of the processing channels which can be allocated to the individual user operable controls. Also, a single processing channel can be allocated to a user operable control on two sub-panels of the control panel and the user operable controls on both sub-panels can be used separately to control the processing within that channel. The resulting changes in the user operable control 'positions' are displayed as a result of the dual control of a processing function within a processing channel by respective user operable controls on the respective sub-panels.

An audio mixing console for processing a plurality of audio channels, in each of which a plurality of audio processing functions are to be performed, has a control panel including a plurality of input fields for selecting audio processing functions, displaying an audio processing function selected and indicating a selected order of audio processing functions for the audio processing channel stages. A stereo mode which can be selected at an input field links adjacent channels. Grouped side chain processes can be defined. A recording input matrix provides a track bounce facility for preserving a channel mix on re-recording a mix of previously recorded tracks. Values for cue faders can be loaded automatically from the main channel faders. Selectable delays can be provided at each processing stage to maintain channel alignment. Also, the chaining of analogue audio functions is provided.

Digital audio processing apparatus comprises: device for detecting the magnitude of an input digital audio signal; and a variable gain element for applying a gain to the input digital audio signal dependent on the detected magnitude of the input digital audio signal, in which:

Digital audio processing

Digital audio processing apparatus for applying a time-varying gain to an input digital audio signal over contiguous first, second and third time periods, in which: the applied gain changes at no more than a first maximum rate of change during the first time period; the applied gain changes at no more than a second maximum rate of change during the third time period; and during the second time period the rate of change of the applied gain varies monotonically from a substantially zero rate of change towards the second maximum rate of change.

Signal processing apparatus comprises at least one digital signal processing device mounted on a circuit board, for performing sample-based signal processing at a sampling frequency; and a switched mode power supply mounted on the circuit board, the switched mode power supply operating at a switching frequency derived from the sampling frequency of the digital signal processing device.

Signal processing apparatus and method with a clock signal generator for

An amplifier comprises a variable gain analog amplifier for amplifying an input analog signal to generate an intermediate analog signal, the gain of the analog amplifier being switchable between two or more discrete gain values. An analog to digital converter converts the intermediate analog signal into a corresponding intermediate digital signal and a variable gain digital amplifier amplifies the intermediate digital signal. A gain control circuit, responsive to a required gain, selects one of the discrete gain values of the analog amplifier and a gain value of the digital amplifier so that the sum of the selected gain values is substantially equal to the required gain; and whether the required gain is increasing or decreasing is detected. If the required gain is decreasing, a delay circuit delays, by a predetermined period longer than a gain switching period of the analog amplifier, a step change in the gain value of the digital amplifier when the gain control circuit changes the selected discrete gain value for the analog amplifier. This can avoid subjectively disturbing transient boosts in the overall system gain when the analog amplifier's gain is switched.

Hybrid analog and digital amplifier with a delayed step change in the

A linear control arrangement, of which a plurality may be provided in an audio mixing console, includes a fader potentiometer having a knob in which a tactile switch is recessed. The switch enables and inhibits recording and/or amending of the fader movement history, and allows ready overwriting or other amendment of existing fader movement data when required. The arrangement allows single finger operation of both the knob and the switch, as well as overcoming the need to provide separate space on the panel for the switch.

Linear control arrangements

In a digital-to-analog conversion system, an input digital signal D is separated by means of an inverter into first and second signal paths, one of which is the inverse of the other. A digital random noise signal R is then added to the direct and inverse signals to form combined digital signals R-D, R+D. The combined signals are converted into analog form by two identical D/A converter devices to provide analog signals R-D+E1, R+D+E2 (E1 and E2 representing the errors introduced in the conversion process), and these are then subtracted to form an analog output 2D-E1+E2. Thus the random noise components are removed from the analog output, and also the errors E1 and E2 tend to cancel each other leading to a reduction in distortion. Moreover, any remaining distortion is randomized and thus harmonic distortion is reduced. When the injected random noise signal has a greater resolution than the converter devices, there is also an overall increase in data resolution. A similar technique may also be applied to analog-to-digital conversion systems.

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Witney, United Kingdom

Paul Anthony Frindle