DROK Extremely Accurate AS30 Dual-channel 30 Segment LED Music Sound Audio Spectrum Level Display VU Meter, the Color Spectrum for Listening Music, Amplifier The AS30 Stereo spectrum analyzer is very responsive to rhythm, accurate, dynamic, has concise appearance and high display accuracy the music visualizer has been Reserved mounting holes and input port to connect external Leads for modification 7 kinds of classic display modes: 1 columnar mode; 2 columnar with peak mode; 3 columnar with peak, peak upward moving out mode; 4 mirror mode, from middle to both sides; 5 single point mode; 6 single peak upward moving out mode; 7 single peak mode Speed and gain: according to personal preferences to adjust the falling speed of 1-10 levels; 1-3 levels are gain attenuation, 4 level is 0 gain, 5-6 levels are gain amplification please adjust input volume and gain to make the LED spectrum display Amplitude at an appropriate range(4 level gain is the best) Key operation: short press the Key to switch among seven kinds of classic display modes; long press the Key for 1 second to adjust among 10-level speed; long press the Key for 3 seconds to switch among 6-level gain all settings has power-off memory function Powered by DC 5V, audio dual-channel input, please control the input level within 5V, too high will damage the chip; and it's better to use this spectrum analysers with filter Plate or shell to make the Brightness best