Reflected sound rendering using downward firing drivers

Patent metadata

Field	Value
Publication number	US-9986338-B2
Application number	US-201515107031-A
Country	US
Kind code	B2
Filing date	Jan 6, 2015
Priority date	Jan 10, 2014
Publication date	May 29, 2018
Grant date	May 29, 2018

Abstract

Embodiments are directed to speakers and circuits that reflect sound off a wall surface ( 114 ) to a listening location at a distance from a speaker. The reflected sound ( 103 ) provides direct audio cues to reproduce audio objects that have direct audio components without the need for direct firing speakers. The speaker comprises sideward firing drivers ( 108 ) to reflect sound off of the wall surface ( 114 ) and represents a virtual direct speaker ( 116 ). A virtual direct filter is applied to the sideward-firing driver signal to improve the perception of direct audio transmitted by the sideward firing speaker ( 108 ) to provide optimum reproduction of the reflected sound. The virtual direct filter may be incorporated as part of a crossover circuit that separates the full band and sends high frequency sound to the sideward-firing driver ( 108 ).

First claim

What is claimed is:

1. A system for rendering sound using reflected sound elements, comprising:
a renderer generating main signal components of an audio signal intended to be reflected off of a side surface of a listening environment, and height signal components of the audio signal intended to be transmitted directly into the listening environment;
at least one speaker for playing the audio signal, and having at least one direct firing driver for transmission of the height signal components and at least one sideward firing driver for transmission of the main signal components;
a unitary cabinet containing both the sideward firing driver and the direct firing driver, wherein the sideward firing driver is disposed at an inclination angle of between 30 degrees and 45 degrees relative to a horizontal angle defined by the direct firing driver, and further wherein the sideward firing driver is coupled to the unitary cabinet through a movable apparatus;
a direct filter configured to at least partially remove directional cues from the at least one speaker location, and at least partially insert the directional cues from a reflected speaker location.

2. The system of claim 1 wherein the direct filter comprises a circuit embodied in one of: a component disposed between the renderer and the at least one speaker, a component provided as part of the renderer, and a component built into the at least one speaker.

3. The system of claim 1 wherein the audio signal comprises a full bandwidth signal, the system further comprising a crossover circuit configured to transmit high frequency components above a cutoff frequency to the direct firing driver and low frequency components below the cutoff frequency to the sideward firing driver.

4. The system of claim 1 wherein the direct firing driver is configured to transmit sound directly downward to a listening area in the listening environment.

5. The system of claim 1 wherein the direct firing and sideward firing drivers are provided in one of a unitary enclosure or separate enclosure system installed in a ceiling of the listening environment.

6. The system of claim 1 wherein the direct firing and sideward firing drivers are provided in one of a unitary enclosure or separate enclosure system mounted on a ceiling of the listening environment.

7. The system of claim 1 wherein the direct firing and sideward firing drivers comprise at least part of a surround sound system installed in a ceiling portion of the listening environment.

8. A system for rendering sound using reflected sound elements, comprising:
a speaker placed at a speaker location and comprising a housing enclosing a plurality of drivers, wherein a first driver of the plurality of drivers is a downward-firing driver configured to transmit sound waves along a first axis proximately perpendicular to the ground plane, and a second driver of the plurality of drivers is a sideward-firing driver oriented at a variable inclination angle relative to the ground plane and configured to reflect sound off a wall surface of a listening environment to produce a reflected speaker location;
a virtual direct filter applying a frequency response curve to an audio signal generated by a renderer and transmitted to the sideward-firing driver, wherein the virtual direct filter at least partially removes directional cues from the speaker location and at least partially inserts the directional cues from the reflected speaker location;
a location component configured to determine an optimum listening position within the listening environment;
a communication component configured to communicate the optimum listening position to the speaker; and
a control component configured to alter the inclination angle to reflect the sound waves off of the wall surface to the optimum listening position.

9. The system of claim 8 wherein the audio signal comprises a full bandwidth signal, the system further comprising a crossover coupled to the speaker, the crossover having a low-pass section configured to transmit low frequency signals below a threshold frequency to the sideward-firing driver, and a high-pass section configured to transmit high frequency signals above the threshold frequency to the direct firing driver.

10. The system of claim 9 wherein the virtual direct filter is integrated with the crossover as part of an integrated crossover/filter circuit.

11. The system of claim 10 wherein the crossover/filter circuit is one of: a digital component implemented as a digital signal processor (DSP) device or a logic gate circuit, and an analog circuit, and wherein the crossover/filter circuit is one of a: passive device network and an active device network.

12. The system of claim 8 further comprising a detection component configured to detect the presence of the virtual direct filter in the listening environment.

13. The system of claim 8 further comprising a bypass switch to bypass the virtual direct filter during a calibration process that prepares audio playback equipment to transmit the sound waves to the listening environment.

14. The system of claim 8 further comprising a room correction component performing a pre-emphasis filtering operation on the sound waves transmitted to the listening environment to compensate for the virtual direct filtering applied to the signal transmitted to the sideward-firing driver.

15. The system of claim 8 wherein the direct firing and sideward firing drivers are provided in one of a unitary enclosure or separate enclosure system installed in a ceiling of the listening environment.

16. The system of claim 8 wherein the direct firing and sideward firing drivers are provided in one of a unitary enclosure or separate enclosure system mounted on a ceiling of the listening environment.

17. The system of claim 8 wherein the direct firing and sideward firing drivers comprise at least part of a surround sound system installed in a ceiling portion of the listening environment.

18. A speaker for transmitting sound waves to be reflected off a wall surface of a listening environment, comprising:
a housing;
a sideward-firing driver within the housing and oriented at an inclination angle relative to a ground plane and configured to reflect sound off a reflection point on the wall surface of the listening environment;
a virtual direct filter applying a frequency response curve to a signal transmitted to the sideward-firing driver, wherein the virtual direct filter is configured to remove height cues present in sound waves transmitted directly through the listening environment in favor of height cues present in the sound reflected off the wall surface of the listening environment; and
a partially blocking baffle system blocking direct off-axis energy to the listening position from the sideward firing driver.

19. The speaker of claim 18 , further comprising a direct-firing driver within the housing configured to transmit sound waves along an axis proximately perpendicular to the ground plane.

Assignees

• Dolby Laboratories Licensing Corp

Inventors

• Mansfield Warren
• Radzik Eugene Edward
• Seefeldt Alan J
• Smith Jared
• Brown C Phillip
• Smithers Michael

Classifications

• H04S7/307

  Frequency adjustment, e.g. tone control (H04S7/301 takes precedence) · CPC title

• H04R2201/021

  Transducers or their casings adapted for mounting in or to a wall or ceiling · CPC title

• H04R1/345

  for loudspeakers · CPC title

• H04S2400/11

  Positioning of individual sound objects, e.g. moving airplane, within a sound field (H04S2420/13 takes precedence) · CPC title

• H04R5/04

  Circuit arrangements, {e.g. for selective connection of amplifier inputs/outputs to loudspeakers, for loudspeaker detection, or for adaptation of settings to personal preferences or hearing impairments (combinations of amplifiers H03F3/68; stereophonic systems H04S)} · CPC title