Frequency characteristics determination device

A frequency characteristics determination device comprising:

• a setting section for setting a first pass point through which a frequency response curve of an audio signal should pass, and a second pass point whose frequency is higher than a frequency of the first pass point;
• a determination section for determining first and second direction points of a Bezier curve connecting the set first and second pass points based on the set first and second pass points;
• a comparing section for comparing a first frequency of the first direction point through which a tangent of the Bezier curve at the first pass point passes with a second frequency of the second direction point through which a tangent of the Bezier curve at the second pass point passes;
• a moving section for, when the comparing section determines that the first frequency is higher than the second frequency, moving at least one of the first and second direction points so that the first frequency is not more than the second frequency;
• a generation section for generating a Bezier curve based on the first and second pass points and the first and second direction points;
• and
• a changing section for changing the frequency response curve of the audio signal according to the Bezier curve generated by the generation section.

A recording medium in which a control program is stored, the control program allowing a computer installed into a frequency characteristics determination device to execute:

• a step of setting a first pass point through which a frequency response curve of an audio signal should pass and a second pass point whose frequency is higher than a frequency of the first pass point;
• a step of determining one or more direction points of a Bezier curve connecting the set first and second pass points based on the set first and second pass points;
• a step of determining whether frequencies of the determined one or more direction points are within a range between not less than the frequency of the first pass point and not more than the frequency of the second pass point;
• a step of moving the one or more direction points so that frequencies of the one or more direction points are within the range when the determination is made that the frequencies of the one or more direction points are out of the range;
• a step of generating a Bezier curve based on the one or more direction points and the first and second pass points;
• a step of changing the frequency response curve of the audio signal according to the generated Bezier curve.

A recording medium in which a control program is stored, the control program allowing a computer installed into a frequency characteristics determination device to execute:

• a step of setting a first pass point through which a frequency response curve of an audio signal should pass and a second pass point whose frequency is higher than a frequency of the first pass point;
• a step of determining first and second direction points of a Bezier curve connecting the set first and second pass points based on the set first and second pass points;
• a step of comparing a first frequency of the first direction point through which a tangent of the Bezier curve at the first pass point passes with a second frequency of the second direction point through which a tangent of the Bezier curve at the second pass point passes;
• a step of, when a determination is made that the first frequency is higher than the second frequency, moving at least one of the first and second direction points so that the first frequency is not more than the second frequency;
• a step of generating a Bezier curve based on the first and second pass points and the first and second direction points;
• and
• a step of changing the frequency response curve of the audio signal according to the generated Bezier curve.