System for implementing filter control, filter controlling method, and frequency characteristics controlling method

Patent metadata

Field	Value
Publication number	US-11228836-B2
Application number	US-202017028187-A
Country	US
Kind code	B2
Filing date	Sep 22, 2020
Priority date	Mar 23, 2018
Publication date	Jan 18, 2022
Grant date	Jan 18, 2022

Abstract

A system for implementing filter control includes an audio processing apparatus, an analog-to-digital converter, a digital-to-analog converter, a filter, and a processor. The processor is configured to receive parameters that define a frequency response in a given frequency bandwidth. The processor is also configured to generate, based on the parameters, a response curve representative of a frequency response of a filter. The processor is also configured to generate, based on the response curve, a filter coefficient of the filter. The lower inclined portion corresponds to, within the given frequency bandwidth, a frequency bandwidth that is lower than a frequency bandwidth corresponding to the upper inclined portion.

First claim

What is claimed is:

1. A system for implementing filter control comprising:
an audio processing apparatus;
an analog-to-digital converter;
a digital-to-analog converter;
a filter; and
a processor, the processor being configured to:
receive parameters that define a frequency response in a given frequency bandwidth,
wherein the given frequency bandwidth includes:
a lower inclined portion in which a gain changes;
an upper inclined portion in which the gain changes; and
a center inclined portion in which the gain changes and that is present between the lower inclined portion and the upper inclined portion;

generate, based on the parameters, a response curve representative of a frequency response of a filter; and
generate, based on the response curve, a filter coefficient of the filter, wherein
the lower inclined portion corresponds to, within the given frequency bandwidth, a frequency bandwidth that is lower than a frequency bandwidth corresponding to the upper inclined portion.

2. A filter controlling method implemented by a processor, the filter controlling method comprising:
receiving parameters that define a frequency response in a given frequency bandwidth,
wherein the given frequency bandwidth includes:
a lower inclined portion in which a gain changes;
an upper inclined portion in which the gain changes; and
a center inclined portion in which the gain changes and that is present between the lower inclined portion and the upper inclined portion;

generating, based on the parameters, a response curve representative of a frequency response of a filter; and
generating, based on the response curve, a filter coefficient of the filter, wherein
the lower inclined portion corresponds to, within the given frequency bandwidth, a frequency bandwidth that is lower than a frequency bandwidth corresponding to the upper inclined portion.

3. The filter controlling method according to claim 2 , wherein the parameters include a parameter that corresponds to a filter element of the filter.

4. The filter controlling method according to claim 2 , wherein the frequency response in a frequency bandwidth outside of the given frequency bandwidth has a reference level, irrespective of values of the parameters.

5. The filter controlling method according to claim 2 , wherein a gradient of the center inclined portion and the gain in the center inclined portion are defined by the specific parameter.

6. The filter controlling method according to claim 5 , wherein a position and a width of the center inclined portion, on the frequency axis, are further defined by the specific parameter.

7. The filter controlling method according to claim 2 , wherein the generating the response curve includes adjusting the response curve such that:
the response curve is continuous at a boundary between the lower inclined portion and the center inclined portion, and
the response curve is continuous at a boundary between the upper inclined portion and the center inclined portion.

8. A frequency characteristics controlling method implemented by a processor, the method comprising
providing a filter element that controls frequency characteristics of a sound signal in a specific frequency bandwidth,
the controlling of the frequency characteristics includes:
controlling, based on a first parameter and a second parameter, a position and a width of the specific frequency bandwidth on a frequency axis; and
controlling, based on a third parameter and a fourth parameter, a gradient of a frequency response in the specific frequency bandwidth, and a gain of the frequency response in the specific frequency bandwidth.

Assignees

• Yamaha Corp

Inventors

• Ishizuka Kenji
• Tamiya Kenichi
• Mita Takashi
• Kaneko Shinichiro

Classifications

• H04R3/04 Primary

  for correcting frequency response · CPC title

• H03H17/02

  Frequency selective networks {(digital computers for complex mathematical operations G06F17/10)} · CPC title