用于控制音质的NF型调制控制电路，因仅能进行低音和高音的增强和衰减，所以不能进行细微的频率特性的补偿。述有，如果想使可听频带域的任意频率均可变，一般使用被称为图形均衡器的装置。这里使用DSP的例子在不断增加，如果要使用简单的电路则使用OP放大器较好。这种图形均衡器是将补偿的中心频率分割为5～7份，分别进行控制，由5个RLC电路组成，十分实用。分割的各个频率是以可听频率范围为对称轴均等分配而决定。-NF-modulation control circuit to control the sound quality, bass and treble enhancement and attenuation, it is not due to only subtle frequency characteristics of compensation. Described there, if you want the audible frequency band domain at any frequency can be changed, the general use of the device is called a graphic equalizer. Example of using DSP is increasing, if you want to use a simple circuit using OP amplifier is better. The graphic equalizer is the center frequency of the compensation split 5-7, respectively, to control by five RLC circuit is very useful. The split frequency is audible frequency range for the axis of symmetry equalization allocation decisions.