Externally coupled loudspeaker system for a vehicle

Patent metadata

Field	Value
Publication number	US-10235985-B2
Application number	US-201615389561-A
Country	US
Kind code	B2
Filing date	Dec 23, 2016
Priority date	Dec 23, 2015
Publication date	Mar 19, 2019
Grant date	Mar 19, 2019

Abstract

A loudspeaker system is provided that includes a loudspeaker that is arranged in a baffle between a passenger compartment of a vehicle and the outside of the passenger compartment. The loudspeaker is configured to radiate an acoustical signal to the passenger compartment. The loudspeaker system further includes active noise control system wherein a microphone is acoustically coupled to the loudspeaker via a secondary path, and the loudspeaker is electrically coupled to the microphone via an active noise control filter.

First claim

What is claimed is:

1. A loudspeaker system comprising:
a loudspeaker that is arranged in a baffle between a passenger compartment of a vehicle and an outside of the passenger compartment, wherein the loudspeaker is configured to radiate an acoustical signal to the passenger compartment;
a passive noise reduction system configured to eliminate high frequency noise; and
an active noise control system, wherein:
a microphone is acoustically coupled to the loudspeaker via a secondary path,
the loudspeaker is electrically coupled to the microphone via an active noise control filter,
the loudspeaker comprises a first side and a second side and wherein the first side faces the passenger compartment of the vehicle and the second side faces an outside of the vehicle, and
the microphone is arranged at the first side of the loudspeaker and adjacent to the passive noise reduction system.

2. The loudspeaker system of claim 1 , wherein
the loudspeaker is connected to a loudspeaker input path;
the microphone is connected to a microphone output path;
a subtractor is connected downstream of the microphone output path and a first useful-signal path;
the active noise control filter is connected downstream of the subtractor;
an adder is connected between the active noise control filter and the loudspeaker input path and to a second useful-signal path; and
both of the first and second useful-signal paths are supplied with a useful signal to be reproduced.

3. The loudspeaker system of claim 2 , wherein
at least one of the first and second useful-signal paths comprises one or more spectrum shaping filters.

4. The loudspeaker system of claim 2 , wherein the active noise control filter is configured to eliminate low frequency noise.

5. The loudspeaker system of claim 1 , wherein the active noise control filter is configured to eliminate noise at frequencies below 1 kHz and the passive noise reduction system is configured to eliminate noise at frequencies above 1 kHz.

6. The loudspeaker system of claim 1 , wherein the active noise control filter is configured to eliminate noise at frequencies below 500 Hz and the passive noise reduction system is configured to eliminate noise at frequencies above 500 Hz.

7. The loudspeaker system of claim 1 , wherein the passive noise reduction system comprises at least one layer of insulation wool.

8. The loudspeaker system of claim 7 , wherein the microphone is enclosed by the at least one layer of insulation wool of the passive noise reduction system.

9. The loudspeaker system of claim 7 , wherein the at least one layer of insulation wool is arranged adjacent to a membrane of the loudspeaker and wherein:
the membrane is arranged between the passenger compartment and the layer of insulation wool,
the layer of insulation wool is arranged between the passenger compartment and the membrane, or
the membrane is arranged between two layers of insulation wool.

10. The loudspeaker system of claim 1 , wherein the baffle comprises an opening in which the loudspeaker is disposed.

11. A method for noise reducing sound reproduction comprising:
radiating an acoustical signal to an inside of a passenger compartment of a vehicle with a loudspeaker that is arranged in a baffle between the passenger compartment and an outside of the passenger compartment;
reducing a disturbing signal with an active noise control system comprising a microphone that is acoustically coupled to the loudspeaker via a secondary path, wherein the loudspeaker is electrically coupled to the microphone via an active noise control filter; and
eliminating high frequency noise via a passive noise reduction system, wherein:
the loudspeaker comprises a first side and a second side and wherein the first side faces the passenger compartment of the vehicle and the second side faces an outside of the vehicle, and
the microphone is arranged at the first side of the loudspeaker and adjacent to the passive noise reduction system.

12. The method of claim 11 further comprising:
supplying a loudspeaker input signal to the loudspeaker;
receiving the acoustical signal radiated by the loudspeaker to provide a microphone output signal;
subtracting the microphone output signal from a useful-signal to generate a filter input signal;
filtering the filter input signal in an active noise control filter to generate an error signal; and
adding the useful-signal to the error signal to generate the loudspeaker input signal.

13. A loudspeaker system comprising:
a loudspeaker arranged in a baffle and positioned between a passenger compartment of a vehicle and an outside of the passenger compartment, wherein the loudspeaker is configured to radiate an acoustical signal to the passenger compartment;
a passive noise reduction system configured to eliminate high frequency noise; and
an active noise control system including a microphone that is acoustically coupled to the loudspeaker via a secondary path and being configured to reduce a disturbing signal in the passenger compartment,
wherein the loudspeaker is electrically coupled to the microphone via an active noise control filter,
wherein the loudspeaker comprises a first side and a second side,
wherein the first side faces the passenger compartment of the vehicle and the second side faces an outside of the vehicle, and
wherein the microphone is arranged at the first side of the loudspeaker and adjacent to the passive noise reduction system.

14. The loudspeaker system of claim 13 , wherein
the loudspeaker is connected to a loudspeaker input path;
the microphone is connected to a microphone output path;
a subtractor is connected downstream of the microphone output path and a first useful-signal path;
the active noise control filter is connected downstream of the subtractor;
an adder is connected between the active noise control filter and the loudspeaker input path and to a second useful-signal path; and
both of the first and second useful-signal paths are supplied with a useful signal to be reproduced.

15. The loudspeaker system of claim 14 , wherein at least one of the first and second useful-signal paths comprises one or more spectrum shaping filters.

16. The loudspeaker system of claim 14 , wherein the active noise control filter is configured to eliminate low frequency noise.

Assignees

• Harman Becker Automotive Systems Gmbh

Inventors

• Christoph Markus
• Pfeffer Andreas

Classifications

• G10K11/162

  Selection of materials · CPC title

• G10K2210/509

  Hybrid, i.e. combining different technologies, e.g. passive and active · CPC title

• G10K2210/3026

  Feedback · CPC title

• H04R1/025

  Arrangements for fixing loudspeaker transducers, e.g. in a box, furniture · CPC title

• G10K2210/1282

  Automobiles · CPC title