Dolby Laboratories Licensing Corporation

Motorola Corporation

Dolby International Ab

Dolby Laboratories Corporation

Michael John Smithers

Alan Jeffrey Seefeldt

Brett Graham Crockett

Jeffrey Charles Riedmiller

C Phillip Brown

Corey I Cheng

David N Lathrop

David S McGrath

Charles Quito Robinson

Regunathan Radhakrishnan

Andrew Peter Reilly

Remi Samuel Audfray

Juan Felix Torres

Kenneth James Gundry

Garth Norman Showalter

Patrick David Saunders

Heiko Purnhagen

James J Croft, Iii

Michael Mead Truman

Mark R P Thomas

Stephen Decker Vernon

Simon Boland

Nicholas Luke Appleton

Farhad Farahani

Warren Mansfield

Mark Thomson

Marvin Pribadi

Jared Smith

William Thomas Rowley

Eugene Edward Radzik

Brian George Arnott

Zhenjie Wu

Jyri Tapani Pakarinen

Ho Young Sung

Some disclosed methods involve multi-band bass management. Some such examples may involve applying multiple high-pass and low-pass filter frequencies for the purpose of bass input management. Some disclosed methods treat at least some low-frequency signals as audio objects that can be panned. Some disclosed methods involve panning low and high frequencies separately. Following high-pass rendering, a power audit may determine a low-frequency deficit factor that is to be reproduced by subwoofers or other low-frequency-capable loudspeakers.

Methods and devices for bass management

A system and method of adjusting an audio output in one location so that its propagation into another location is reduced. As a first device in a first location generates sound, a second device in a second location detects the propagated sound. The first device then adjusts its output based on the detected sound.

Reducing unwanted sound transmission

An apparatus and method of excursion protection of a loudspeaker. The method includes attenuating selected bands in a transform domain, controlled by a feedback signal resulting from an excursion transfer function that has been modified according to the real-time operational characteristics of the loudspeaker. In this manner, the system reduces the amount of wideband attenuation needed to address the predicted excursion, resulting in a better listening experience.

Loudspeaker excursion protection

A speaker for transmitting reflected sound waves off an upper surface down to a listening environment, comprising: a cabinet containing a plurality of audio drivers, direct-firing drivers within the cabinet oriented to transmit sound along a horizontal axis substantially perpendicular to a front surface of the cabinet, and a pair of upward-firing slotted drivers placed proximate to ends of an top surface of the cabinet and oriented at an inclination angle relative to the horizontal axis. The slotted drivers are configured to create an overlapping reflected sound projection for high frequency sound when reflected down to a listening position located at a distance in front of the speaker pair. Such a speaker projects reflected sound that provides wider horizontal or side-to-side dispersion to better cover the listening area.

Upward firing loudspeaker having asymmetric dispersion for reflected sound rendering

Embodiments are directed to an upward-firing speaker that reflects sound off a ceiling to a listening location at a distance from a speaker. The reflected sound provides height cues to reproduce audio objects that have overhead audio components. The speaker comprises a direct-firing tweeter and an upward-firing full-range driver in a unitary enclosure for playback of front-channel and height-channel signals, respectively. A crossover passes high frequencies of a front-channel signal directly to the tweeter and combines low frequencies of the front-channel signal with the height channel signal to be played through the full-range driver. A virtual height filter is applied to the height channel signal to improve the perception of height for audio signals transmitted by the virtual height speaker to provide optimum reproduction of the overhead reflected sound.

Audio speaker with full-range upward firing driver for reflected sound projection

A dual wave-column, dual-driver loudspeaker enclosure is described. The two drivers are cross-coupled through their respective front and back sides by two single exit wave-columns. At the &#xbc; wavelength frequency of the waveguide length, both drivers resonate with the waveguides, and cone motion is minimized while output is maximized. At the &#xbd; wavelength frequency, the front wave of the first driver is in-phase with, the rear wave of the second driver such that the output is increased, reinforced, and smoothed at that frequency. At the &#x2153; wavelength frequency, the two wave-column mouth outputs exhibit acoustic mutual coupling, which boosts acoustic output and reduces cone motion at the critical maximum displacement frequency.

Multi-driver loudspeaker with cross-coupled dual wave-columns

Estimates of spectral magnitude and phase are obtained by an estimation process using spectral information from analysis filter banks such as the Modified Discrete Cosine Transform. The estimation process may be implemented by convolution-like operations with impulse responses. Portions of the impulse responses may be selected for use in the convolution-like operations to trade off between computational complexity and estimation accuracy. Mathematical derivations of analytical expressions for filter structures and impulse responses are disclosed.

Coding techniques using estimated spectral magnitude and phase derived from MDCT coefficients

An acoustic manifold for altering a sound wavefront shape from a loudspeaker having a substantially planar driver, comprising a mounting surface configured to attach to a front surface of a case surrounding the driver and having two vertical openings matching corresponding vertical openings in the case to allow sound from the driver to project therethrough, and a waveguide portion coupled to the mounting surface and having a structure channeling sound projected from the driver through the two vertical openings to be combined in one output area. The structure has a plurality of reflective surfaces configured to create output sound that has a consistent dispersion pattern over a defined area. The manifold is configured to increase a vertical and/or horizontal beamwidth of the projected sound so that listeners positioned off an axis of the loudspeaker will hear a wide range of audible frequencies at a substantially similar sound level.

Planar loudspeaker manifold for improved sound dispersion

Embodiments are directed to a virtual height filter for use with or in an upward-firing speaker system that reflects sound off a ceiling to a listening location at a distance from a speaker, and that provides height cues to reproduce audio objects that have overhead audio components. A virtual height filter based on a directional hearing model is applied to the upward-firing driver signal to improve the perception of height for audio signals transmitted by the virtual height speaker to provide optimum reproduction of the overhead reflected sound. The virtual height filter is provided by any one or combination of analog or digital filter circuits, or mechanical structures including speaker grill, enclosure, or driver design or configuration.

Passive and active virtual height filter systems for upward firing drivers

A soundbar speaker for transmitting reflected sound waves off an upper surface down to a listening environment, comprising: a cabinet containing a plurality of audio drivers, direct-firing drivers within the cabinet oriented to transmit sound along a horizontal axis substantially perpendicular to a front surface of the cabinet, and a pair of upward-firing slotted drivers placed proximate to ends of an top surface of the cabinet and oriented at an inclination angle relative to the horizontal axis. The slotted drivers are configured to create an overlapping reflected sound projection for high frequency sound when reflected down to a listening position located at a distance in front of the speaker pair. Such a speaker projects reflected sound that provides wider horizontal or side-to-side dispersion to better cover the listening area.

A device () and a method are proposed for tuning a frequency-dependent attenuation stage (), with the purpose of suppressing non-linear distortion occurring in an audio reproduction system () associated with the frequency-dependent attenuation stage. The device comprises a receiving section () adapted to receive data representing an output acoustic signal () from the audio reproduction system, recorded upon excitation of the audio reproduction system by a predetermined input data signal ()first distortion detection section () adapted to detect presence of non-linear distortion based on the received data and to apply psycho-acoustic compensation to the detected non-linear distortion and a control section () adapted to determine, based on the psycho-acoustically compensated non-linear distortion, control information () suitable for controlling the frequency-dependent attenuation stage.

Device and method for tuning a frequency-dependent attenuation stage

Systems and methods for leveling loudness variation in an audio signal are described. Embodiments use both a perceptual leveling algorithm and a standards-based loudness measure together to minimize audio process artifacts and ensure that the measured loudness of the processed audio is close to a required measure, according to a particular standard measurement of loudness. These systems and methods can be used either offline or in real-time.

System and method for leveling loudness variation in an audio signal

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Kareela, Australia

Michael John Smithers