1、CONTROL RANGE: The 7 band equalizer circuit has a control range of ±12dB. equalization bands: 60Hz, 150Hz, 400Hz, 1KHz, 3KHz, 6.5KHz, 15KHz, by TI or ST TL074. 2、BASIC PARAMETERS: 7 band sound equalizer preamplifier gain, 4580 classic op amp provides 5x amplification (14dB); input impedance is 20K, output impedance is 600Ω. 3、COMPATIBLE HEADPHONES: The ear amplifier part of the sound equalizer consists of NE5532 type 47 headphone driver circuit, easy to drive various types of headphones, adjustable high and low, with sound cable. 4、3.5MM INTERFACE: 3.5mm input interface supports 4 pole plug, the output terminal connects to a headset with microphone, which can be used for normal voice calls on a cell phone, and the other terminal has a Qunlian interface for choice. 5、ALUMINUM ALLOY MATERIAL: The 7 band car sound equalizer is made of aluminum alloy, high strength, stable performance, DC 5‑12V power supply, dual channel sound.