Sound field correcting method in audio system

• US 20010017921A1
• Filed: 02/13/2001
• Published: 08/30/2001
• Est. Priority Date: 02/14/2000
• Status: Active Grant

• Current Assignee: Pioneer Corporation
• Original Assignee: Pioneer Corporation
• Inventors: Ohta, Yoshiki
• Granted Patent: US 7,068,799 B2
• Time in Patent Office: Days
• US Class Current: 381/98
• CPC Class Codes: H04S 3/00 Systems employing more than two channels, e.g. quadraphonic H04S5/00, H04S7/00 take precedence
• CPC Class Codes: H04S 7/301 Automatic calibration of stereophonic sound system, e.g. with test microphone
• CPC Class Codes: H04S 7/302 Electronic adaptation of stereophonic sound system to listener position or orientation H04S7/301 takes precedence
• CPC Class Codes: H04S 7/307 Frequency adjustment, e.g. tone control H04S7/301 takes precedence

Abstract

In correcting the sound field, the loudspeakers 6_FL to 6_WF are sounded by the noise. The attenuation factors of the inter-band attenuators ATF₁₁ to ATF_ki for adjusting gains of the band-pass filters BPF₁₁ to BPF_ki to the frequency in respective channels are corrected based on detection results of the reproduced sounds of the loudspeakers 6_FL to 6_WF. Then, the attenuation factors of the channel-to-channel attenuators ATG₁ to ATG₅ are corrected based on the detection results of the reproduced sounds of the loudspeakers 6_FL to 6_WF. Then, the delay times of the delay circuits DLY₁ to DLY₅ are corrected based on the detection results of the reproduced sounds of the loudspeakers 6_FL to 6_WF. Then, the attenuation factor of the channel-to-channel attenuator ATG_k is corrected based on the detection result of the reproduced sound of the loudspeaker 6_WF as the subwoofer, whereby the levels of the reproduced sounds reproduced by the loudspeakers 6_FL to 6_WF are adjusted to be made flat over the audio frequency band.

Claims

1. A sound field correcting method in an audio system, for supplying audio signals to a first sound generating means having a first reproducing frequency band and a second reproducing frequency band and a second sound generating means having the second reproducing frequency band respectively to reproduce thereof,

said correcting method comprising:

a first step of supplying a noise to said first sound generating means and then detecting a reproduced sound in the first reproducing frequency band and a reproduced sound in the second reproducing frequency band, that are reproduced by said first sound generating means;

a second step of supplying the noise to said second sound generating means and then detecting the reproduced sound in the second reproducing frequency band; and

a third step of adjusting levels of the audio signals supplied to said first sound generating means and said second sound generating means such that a sum of a spectrum average level of the reproduced sound in the second reproducing frequency band reproduced by said first sound generating means and detected by the first step and a spectrum average level of the reproduced sound in the second reproducing frequency band reproduced by said second sound generating means and detected by the second step and a spectrum average level of the reproduced sound in the first reproducing frequency band detected by the first step are set equal to a ratio of predetermined target characteristics.

3. The sound field correcting method in an audio system, according to

claim 1

or

2

, wherein

the first reproducing frequency band is substantially equal to an audio frequency band, and

the second reproducing frequency band is substantially equal to a low frequency band.

4. The sound field correcting method in an audio system, according to

claim 1

, wherein

the first reproducing frequency band is substantially equal to an audio frequency band, and

the second reproducing frequency band is substantially equal to a high frequency band.

2. A sound field correcting method in an audio system, for supplying audio signals to a first sound generating means having a first reproducing frequency band and a second reproducing frequency band and a second sound generating means having the second reproducing frequency band respectively to reproduce thereof,

said correcting method comprising:

a first step of supplying a noise to said first sound generating means and then detecting a reproduced sound in the first reproducing frequency band and a reproduced sound in the second reproducing frequency band, that are reproduced by said first sound generating means;

a second step of supplying the noise to said second sound generating means and then detecting the reproduced sound in the second reproducing frequency band; and

a third step of adjusting levels of the audio signals supplied to said first sound generating means and said second sound generating means such that a ratio of a sum of a spectrum average level of the reproduced sound in the second reproducing frequency band reproduced by said first sound generating means and detected by the first step and a spectrum average level of the reproduced sound in the second reproducing frequency band reproduced by said second sound generating means and detected by the second step to a spectrum average level of the reproduced sound in the first reproducing frequency band detected by the first step is set equal to a predetermined value.