Features
Adjustable notch filter: LCR notch filter, also known as a wave stopper filter, the notch frequency and the amount of cut can be adjusted, the adaptability is wider, and it is more convenient for DIY. The function is to cut and trim the mid and high frequencies to meet the requirement of a flattering overall curve. The sound quality of the full-range speakers is too prominent, the sound is sharp, and the ears are harsh. Effective treatment has been done to make the sound soft, durable and highlight the low frequency!

Specification
Reference value: Inductance: 0.29MH, capacitance 4.7uF + adjustable 4.7uF, resistance 1.8K ohm,
Speaker impedance: 4-8 ohms
Size: 46*58MM
Suitable for speakers: full range speakers under 4 inches