Speaker Device And Filter Coefficient Generating Device Therefor

• US 20130039512A1
• Filed: 04/26/2010
• Published: 02/14/2013
• Est. Priority Date: 04/26/2010
• Status: Active Grant

• Current Assignee: TOA Corporation
• Original Assignee: TOA Corporation
• Inventors: Miyata, Satoshi, Suetsugu, Toshimitsu
• Granted Patent: US 9,118,997 B2
• Time in Patent Office: Days
• US Class Current: 381/97
• CPC Class Codes: H04R 1/403 loud-speakers
• CPC Class Codes: H04R 27/00 Public address systems circuits for preventing acoustic reaction H04R3/02; circuits for distributing signals to loudspeakers H04R3/12; monitoring or testing arrangements for public address systems H04R29/007; amplifiers H03F
• CPC Class Codes: H04R 3/12 for distributing signals to two or more loudspeakers specially adapted for hearing aids H04R25/407

Abstract

To provide a speaker device that can form a substantially uniform sound field over a range from a long distance to a short distance without significantly increasing a calculation load. A plurality of FIR filters 21 to 2n perform delay control of respective speakers so as to increase a delay time difference between adjacent speakers 51 to 5n in a line array speaker 5 toward one end of the line array speaker 5, and thereby over a wide range from a long distance to a short distance, a sound filed 12 is formed. Also, by adding a common shift delay time Dc to filter coefficients for the FIR filters 21 to 2n, the delay time difference between adjacent speakers 51 to 5n is made less than a sampling period of a sound signal to form a wide and uniform sound field 12.

Claims

1. A speaker device comprising:

a line array speaker that includes a plurality of speakers arranged on a same plane at predetermined intervals;

a plurality of FIR filters that correspond to said speakers and each delay a common digital sound signal; and

a plurality of D/A converters that each convert said delayed digital sound signal to an analog sound signal, wherein

said FIR filters delay said digital sound signal so as to increase a ratio of a delay time difference to the arrangement interval between adjacent speakers toward one end of said line array speaker.

2. The speaker device according to claim 1, wherein

said FIR filters delay said digital sound signal such that a minimum value among the delay time differences between the adjacent speakers becomes less than a sampling period of said digital sound signal.

3. The speaker device according to claim 2, wherein

said FIR filters delay said digital sound signal so as to virtually array said speakers on a clothoid curve.

4. The speaker device according to claim 3, comprising

an IIR filter that is adapted to control an amplitude characteristic of said digital sound signal, wherein

said digital sound signal is inputted to said FIR filters through said IIR filter.

5. The speaker device according to claim 4, wherein

said FIR filters compensate for a phase characteristic of said IIR filter.

6. The speaker device according to claim 1, comprising

filter coefficient storage means adapted to rewritably hold filter coefficients for said FIR filters.

7. A filter coefficient generating device for a speaker device that,

to a speaker device comprising:

a line array speaker that includes a plurality of speakers arranged on a same plane at predetermined intervals;

a plurality of FIR filters that correspond to said speakers and each delay a common digital sound signal;

a plurality of D/A converters that each convert said delayed digital sound signal to an analog sound signal; and

filter coefficient storage means adapted to rewritably hold filter coefficients for said FIR filters,

supplies the filter coefficients for said FIR filters, the filter coefficient generating device comprising;

frequency characteristics determination means adapted to, on a basis of user operation, determine frequency characteristics of each of said FIR filters;

filter coefficient calculation means adapted to perform an inverse Fourier transform of said frequency characteristics to obtain each of the filter coefficients for said FIR filters, and generates the filter coefficients for said FIR filters such that a minimum value among delay time differences between adjacent speakers becomes less than a sampling period of said digital sound signal; and

delay shift means adapted to add a common shift delay time to each of said filter coefficients.