YLY-2088 400W Treble-Bass Crossover Dual 2-Way Speaker Audio Crossover Module

This is a 400W filter module for the speakers. Jumper A, B are used to control the audio effect of the bass range. A for lower limit while B for the upper limit of the bass audio range. For some speakers, when the Bass is turned up too much, the speaker will show distortion. When that happens: we remove the jumper cap of jumper A to limit super low Bass to bring distortion lower. When we remove the cap of jumper B, Bass is increased while the cap of Jumper B is on, Bass is decreased. Jumper C and D are used to control the Treble range. When the cap of both jumper C and D are on, the sound of the treble is loudest. When only cap C is on, the treble sound is lower. When only cap D is on, further lower. When both caps of C and D are removed, there is no treble sound.