Vertically Displaced Drivers for Surround Sound Beam-Forming

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Solution Overview

Problem

Existing surround sound systems in home entertainment require complex and costly setups with multiple speakers and obstructed paths for proper sound reflection, limiting speaker placement and increasing installation costs, while simulated surround sound systems fail to replicate the performance of actual surround sound implementations.

Innovation Solution

A beam-forming speaker system using two vertically displaced drivers operating in opposing polarity to direct surround sound as reflections, with an electronic network combining main and surround channel information to create beams that simulate a wider sound environment without the need for a large array of speakers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If actual surround sound implementations use multiple speakers placed behind the listener, then surround sound performance is improved, but device complexity and installation cost increase

Engineering Contradiction:

Improvesurround sound performanceVSAvoidspeaker arrangement complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple speaker functions into a single speaker unit by integrating vertically displaced drivers (first driver facing forward, second driver facing upward) within one speaker housing. This merging approach replicates the functionality of multiple separate speakers while reducing installation complexity and cost.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent transitions from horizontal speaker placement (traditional surround speakers placed behind the listener) to vertical driver displacement within a single speaker. The upward-facing second driver projects sound vertically to create ceiling reflections, adding a vertical dimension to sound projection that replaces the need for multiple horizontally distributed speakers.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Device complexity

If simulated surround sound systems use filtering and delays on stereo signals, then implementation simplicity is improved, but surround sound performance deteriorates

Engineering Contradiction:

Improvesystem implementation simplicityVSAvoidsurround sound performance

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent replaces electronic signal processing methods (filtering and delays) with a physical acoustic mechanism. Instead of using digital signal manipulation to create surround effects, the system uses the physical projection of sound waves vertically by the upward-facing driver to generate natural ceiling reflections, achieving authentic surround sound through acoustic physics rather than electronic simulation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If large horizontal arrays of speakers are used for beam-forming, then surround sound beam directionality is improved, but device complexity and cost increase

Engineering Contradiction:

Improvesound beam directionalityVSAvoidspeaker array complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the horizontal array configuration with a vertical driver displacement arrangement. By positioning the second driver vertically above the first driver and directing it upward at a specific angle, the system creates directed sound beams that reflect off the ceiling to reach the listener from apparent rear positions, achieving beam-forming functionality without requiring multiple horizontally distributed speakers.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution allows for effective simulation of surround sound without the complexity and cost of traditional systems, enabling diffuse sound reflections and improved sound reproduction by directing surround channel information away from the listener, creating a larger acoustic environment from a single speaker placement.

Implementation Method 1

direct surround sound as reflections

Methodology Applied

Scientific EffectSound wave reflection: Reflection

Implementation Method 2

beam-forming speaker system using two vertically displaced drivers operating in opposing polarity to direct surround sound as reflections

Methodology Applied

Scientific EffectAcoustic beam-forming:

Data Source

PatentUS7606377B2Method and system for surround sound beam-forming using vertically displaced drivers

Publication Date: 2009.10.20 CIRRUS LOGIC INC

AI summary

A method and system for surround sound beam-forming using vertically displaced drivers provides a low cost alternative to present external surround array systems. A pair of vertically displaced speaker drivers is supplied with surround and main channel information in a controlled phase relationship with respect to each driver such that the surround channel information is propagated in a directivity pattern substantially differing from that of the main channel information. The main channel information is generally directed at a listening area, while the surround channel information is directed away from the listening area and is substantially attenuated in the direction of the listening area, so that the surround channel information is heard as a diffuse reflected field. An electronic network provides for control of the surround channel phase relationship and combining of main and surround signals for providing inputs to individual power amplifiers for each driver.