Loudspeaker Manifold Layout for Compact Low-Frequency Output

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Solution Overview

Problem

Existing low-frequency sound reproduction systems face challenges in achieving high output, low distortion, and extended frequency response while maintaining a compact size, often sacrificing efficiency and transient response due to limitations in horn loading, manifold design, and the use of passive radiators or ports.

Innovation Solution

A loudspeaker system incorporating a speaker enclosure with a manifold and a woofer and acoustic vent, where the woofer and acoustic vent are positioned at a 180-degree or 90-degree angle, allowing for improved low-frequency efficiency and reduced distortion, and optionally using multiple manifolds and passive radiators or air ports to enhance performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If horn loading is used to provide high efficiency and low distortion, then output efficiency is improved, but system size becomes very large

Engineering Contradiction:
Improveoutput efficiencyVSAvoidsystem size
Core Design Contradiction:
ProductivityVSVolume of stationary object

Solution Approach 1:

The horn is divided into multiple segments or sections that are folded back on themselves, creating a compact configuration. The horn path is segmented into front section, middle section, and rear section that fold within a small enclosure volume while maintaining the acoustic path length needed for efficient low-frequency reproduction.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The folded horn structure nests multiple sections within each other, with the horn path folding back into the enclosure volume. The acoustic path is nested within a compact physical footprint, allowing long acoustic paths to fit within small enclosures.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Volume of stationary object

If multiple drivers, ports or passive radiators are included in a single horn throat to reduce size, then system size is reduced, but efficiency gain and air load effectiveness at low frequencies are severely restricted

Engineering Contradiction:
Improvesystem sizeVSAvoidefficiency gain
Core Design Contradiction:
Volume of stationary objectVSProductivity

Solution Approach 1:

Instead of combining multiple drivers in a single throat, the horn itself is segmented into multiple folded sections. Each section contributes to the overall acoustic path while maintaining proper air loading for low-frequency efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The horn extends in multiple spatial dimensions through folding, rather than simply increasing throat area. The acoustic path travels through three-dimensional space by folding, maintaining effectiveness at low frequencies while reducing the enclosure's external dimensions.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Volume of stationary object

If a folded horn is used to reduce overall size, then system size is reduced, but it remains very large compared to conventional sealed or ported enclosures

Engineering Contradiction:
Improveoverall sizeVSAvoidrelative compactness
Core Design Contradiction:
Volume of stationary objectVSProductivity

Solution Approach 1:

The horn is divided into multiple compact folded sections that fit within a small enclosure. The segmentation allows the long acoustic path to be packed into a volume comparable to conventional enclosures.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The horn utilizes three-dimensional folding to achieve compactness. By extending the acoustic path through multiple dimensions rather than a single linear direction, the overall enclosure size approaches that of conventional sealed or ported designs.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Productivity

If passive radiators with large surface area and high excursion capability are used, then low-frequency output is improved, but system size significantly increases

Engineering Contradiction:
Improvelow-frequency outputVSAvoidsystem size
Core Design Contradiction:
ProductivityVSVolume of stationary object

Solution Approach 1:

The passive radiator is completely removed from the system. Instead, a folded horn design provides the low-frequency output through acoustic resonance and air loading, eliminating the need for additional passive radiator components and their associated space requirements.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The mechanical passive radiator system is replaced with an acoustic field-based folded horn system. The folded horn uses acoustic pressure and air loading to produce low-frequency output without requiring large mechanical excursions or additional radiator surfaces.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

5Volume of stationary object

If very compact enclosures with multiple passive radiators are used, then system size is reduced, but efficiency becomes very low and requires very powerful amplifiers

Engineering Contradiction:
Improveenclosure sizeVSAvoidefficiency
Core Design Contradiction:
Volume of stationary objectVSProductivity

Solution Approach 1:

Passive radiators are removed entirely. The folded horn design provides efficient low-frequency reproduction through acoustic resonance and proper air loading, eliminating the need for multiple passive radiators and their associated inefficiencies.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The mechanical passive radiator system is replaced with an acoustic field system. The folded horn uses acoustic pressure waves and air loading to efficiently transfer energy to the air, providing high efficiency without requiring powerful amplifiers.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

The system achieves higher output efficiency and extended frequency response, particularly in the 20 to 100 Hz range, outperforming conventional designs by several dB, with reduced distortion and improved mechanical reliability.

Implementation Method 1

The voice coil assembly is an electric motor. When current flows through the voice coil wire, the coil moves according to Fleming's left hand rule, causing the coil to push or pull like a piston. The voice coil is typically cemented to the back of the speaker cone, which creates sound waves as it is pushed back and forth.

Methodology Applied
Scientific EffectAcoustic wave generation: Sound

Implementation Method 2

An acoustic vent is mounted on a second wall of the manifold, such that the woofer and the acoustic vent face each other at about a 180 degree angle or about a 90 angle.

Methodology Applied
Scientific EffectAir flow through opening:

Data Source

PatentUS9100739B2High output loudspeaker
Publication Date: 2015.08.04 VOXX INT CORP
  • US9100739B2 patent drawing
  • US9100739B2 patent drawing
  • US9100739B2 patent drawing

AI summary

A loudspeaker system includes a speaker enclosure having an opening in a front wall, and a speaker manifold mounted within the speaker enclosure and communicating with the opening. The speaker manifold includes a pair of substantially parallel side walls, a back wall, and top and bottom walls, defining a manifold chamber. The wall opposite the back wall is substantially open to define a manifold opening and to permit the communicating. The manifold opening is substantially in alignment with the front wall opening. A woofer is mounted on a first wall of the speaker manifold. An acoustic vent is mounted on a second wall of the manifold, such that the woofer and the acoustic vent face each other at one of about a 180 degree angle or about a 90 degree angle.