MULTIBAND DRC SYSTEM AND METHOD FOR CONTROLLING THE SAME

• US 20110110533A1
• Filed: 11/03/2010
• Published: 05/12/2011
• Est. Priority Date: 11/09/2009
• Status: Active Grant

• Current Assignee: N Citron, Inc.
• Original Assignee: NeoFidelity, Inc.
• Inventors: KIM, Min Soo, CHOI, Yeongha
• Granted Patent: US 8,600,076 B2
• Time in Patent Office: Days
• US Class Current: 381/99
• CPC Class Codes: H03G 9/005 of digital or coded signals
• CPC Class Codes: H03G 9/18 for tone control and volume expansion or compression

Abstract

A multiband DRC system and a method for controlling the same are disclosed. In accordance with the present invention, the system and the method are capable of increasing an overall loudness of an output signal by controlling thresholds and gains of plurality of DRCs included in the multiband DRC system according to frequency bands.

Claims

1. A multiband DRC system, comprising:

a filtering unit for dividing a digital audio signal into a first band audio signal through an N^th band audio signal according to (N−

1) crossover frequencies;

a first through an N^th DRC for dynamically compressing the first band audio signal through the N^th band audio signal, respectively; and

an adder for adding output signals of the first DRC through the N^th DRC.

2. The system in accordance with claim 1, further comprising a post DRC for dynamically compressing the output signal of the adder.

3. The system in accordance with claim 2, wherein the filtering unit includes a first through an N^th filter for dividing the digital audio signal into the first band audio signal through the N^th band audio signal, respectively, according to the (N−

1) crossover frequencies.

4. The system in accordance with claim 3, wherein each of the first DRC through the N^th DRC selects each a threshold of the first DRC through the N^th DRC according to a target THD and the (N−

1) crossover frequencies.

5. The system in accordance with claim 1, further comprising a gain controller for controlling gains of the first DRC through the N^th DRC according to an upper limit of differences between the gains.

6. The system in accordance with claim 5, wherein, when the difference between the gains of the L^th DRC and the M^th DRC exceeds the upper limit, the gain controller controls the differences between the gains to be lower than the upper limit by limiting the gain of one of the L^th DRC and the M^th DRC (where each of L and M is a natural number satisfying 1=<

L, M<

=N).

7. A method for controlling a multiband DRC system, comprising steps of:

(a) dividing a digital audio signal into a first band audio signal through an N^th band audio signal according to (N−

1) crossover frequencies;

(b) dynamically compressing the first band audio signal through the N^th band audio signal by inputting a first DRC through an N^th DRC, respectively; and

(c) adding the first band audio signal through the N^th band audio signal dynamically compressed in the step (b).

8. The method in accordance with claim 7, further comprising dynamically compressing the first band audio signal through the N^th band audio signal added in the step (c).

9. The method in accordance with claim 7, wherein the step (a) comprises:

(a-1) selecting a target THD and the crossover frequency; and

(a-2) dividing the digital audio signal into the first band audio signal through the N^th band audio signal according to the (N−

1) crossover frequencies.

10. The method in accordance with claim 9, wherein the step (b) comprises:

(b-1) selecting each a threshold of the first DRC through the N^th DRC according to the target THD and the (N−

1) crossover frequencies; and

(b-2) dynamically compressing the first band audio signal through the N^th band audio signal inputted the first DRC through the N^th DRC, respectively, according to the threshold.

11. The method in accordance with claim 7, wherein the step (b) comprises:

(b-1) inputting the first band audio signal through the N^th band audio signal to the first DRC through the N^th DRC, respectively;

(b-2) selecting gains of the first DRC through the N^th DRC according to an upper limit of differences between the gains; and

(b-3) dynamically compressing the first band audio signal through the N^th band audio signal according to the gains selected in the step (b-2).

12. The method in accordance with claim 11, wherein the step (b-2) comprises, when the difference between the gains of the L^th DRC and the M^th DRC exceeds the upper limit, controlling the differences between the gains to be lower than the upper limit by limiting the gain of one of the L^th DRC and the M^th DRC (where each of L and M is a natural number satisfying 1=<

L, M<

=N).